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GNOME Data Access 4 manual | ![]() |
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Top | Description | Object Hierarchy | Implemented Interfaces | Properties | Signals |
GdaConnection; enum GdaConnectionOptions; enum GdaConnectionError; #define GDA_CONNECTION_ERROR GdaConnection * gda_connection_open_from_dsn (const gchar *dsn
,const gchar *auth_string
,GdaConnectionOptions options
,GError **error
); GdaConnection * gda_connection_open_from_string (const gchar *provider_name
,const gchar *cnc_string
,const gchar *auth_string
,GdaConnectionOptions options
,GError **error
); gboolean gda_connection_open (GdaConnection *cnc
,GError **error
); void gda_connection_close (GdaConnection *cnc
); void gda_connection_close_no_warning (GdaConnection *cnc
); gboolean gda_connection_is_opened (GdaConnection *cnc
); GdaSqlParser * gda_connection_create_parser (GdaConnection *cnc
); gchar * gda_connection_value_to_sql_string (GdaConnection *cnc
,GValue *from
); gchar * gda_connection_quote_sql_identifier (GdaConnection *cnc
,const gchar *id
); gchar * gda_connection_statement_to_sql (GdaConnection *cnc
,GdaStatement *stmt
,GdaSet *params
,GdaStatementSqlFlag flags
,GSList **params_used
,GError **error
); gboolean gda_connection_statement_prepare (GdaConnection *cnc
,GdaStatement *stmt
,GError **error
); GObject * gda_connection_statement_execute (GdaConnection *cnc
,GdaStatement *stmt
,GdaSet *params
,GdaStatementModelUsage model_usage
,GdaSet **last_insert_row
,GError **error
); GdaDataModel * gda_connection_statement_execute_select (GdaConnection *cnc
,GdaStatement *stmt
,GdaSet *params
,GError **error
); GdaDataModel * gda_connection_statement_execute_select_full (GdaConnection *cnc
,GdaStatement *stmt
,GdaSet *params
,GdaStatementModelUsage model_usage
,GType *col_types
,GError **error
); GdaDataModel * gda_connection_statement_execute_select_fullv (GdaConnection *cnc
,GdaStatement *stmt
,GdaSet *params
,GdaStatementModelUsage model_usage
,GError **error
,...
); gint gda_connection_statement_execute_non_select (GdaConnection *cnc
,GdaStatement *stmt
,GdaSet *params
,GdaSet **last_insert_row
,GError **error
); GSList * gda_connection_repetitive_statement_execute (GdaConnection *cnc
,GdaRepetitiveStatement *rstmt
,GdaStatementModelUsage model_usage
,GType *col_types
,gboolean stop_on_error
,GError **error
); GSList * gda_connection_batch_execute (GdaConnection *cnc
,GdaBatch *batch
,GdaSet *params
,GdaStatementModelUsage model_usage
,GError **error
); gboolean gda_connection_begin_transaction (GdaConnection *cnc
,const gchar *name
,GdaTransactionIsolation level
,GError **error
); gboolean gda_connection_commit_transaction (GdaConnection *cnc
,const gchar *name
,GError **error
); gboolean gda_connection_rollback_transaction (GdaConnection *cnc
,const gchar *name
,GError **error
); gboolean gda_connection_add_savepoint (GdaConnection *cnc
,const gchar *name
,GError **error
); gboolean gda_connection_rollback_savepoint (GdaConnection *cnc
,const gchar *name
,GError **error
); gboolean gda_connection_delete_savepoint (GdaConnection *cnc
,const gchar *name
,GError **error
); guint gda_connection_async_statement_execute (GdaConnection *cnc
,GdaStatement *stmt
,GdaSet *params
,GdaStatementModelUsage model_usage
,GType *col_types
,gboolean need_last_insert_row
,GError **error
); GObject * gda_connection_async_fetch_result (GdaConnection *cnc
,guint task_id
,GdaSet **last_insert_row
,GError **error
); gboolean gda_connection_async_cancel (GdaConnection *cnc
,guint task_id
,GError **error
); GdaTransactionStatus * gda_connection_get_transaction_status (GdaConnection *cnc
); GdaConnectionOptions gda_connection_get_options (GdaConnection *cnc
); GdaServerProvider * gda_connection_get_provider (GdaConnection *cnc
); const gchar * gda_connection_get_provider_name (GdaConnection *cnc
); const gchar * gda_connection_get_dsn (GdaConnection *cnc
); const gchar * gda_connection_get_cnc_string (GdaConnection *cnc
); const gchar * gda_connection_get_authentication (GdaConnection *cnc
); const GList * gda_connection_get_events (GdaConnection *cnc
); GdaServerOperation * gda_connection_create_operation (GdaConnection *cnc
,GdaServerOperationType type
,GdaSet *options
,GError **error
); gboolean gda_connection_perform_operation (GdaConnection *cnc
,GdaServerOperation *op
,GError **error
); enum GdaConnectionFeature; gboolean gda_connection_supports_feature (GdaConnection *cnc
,GdaConnectionFeature feature
); GdaMetaStore * gda_connection_get_meta_store (GdaConnection *cnc
); gboolean gda_connection_update_meta_store (GdaConnection *cnc
,GdaMetaContext *context
,GError **error
); enum GdaConnectionMetaType; GdaDataModel * gda_connection_get_meta_store_data (GdaConnection *cnc
,GdaConnectionMetaType meta_type
,GError **error
,gint nb_filters
,...
); GdaDataModel * gda_connection_get_meta_store_data_v (GdaConnection *cnc
,GdaConnectionMetaType meta_type
,GList *filters
,GError **error
); GdaStatement * gda_connection_parse_sql_string (GdaConnection *cnc
,const gchar *sql
,GdaSet **params
,GError **error
); GdaDataModel * gda_connection_execute_select_command (GdaConnection *cnc
,const gchar *sql
,GError **error
); gint gda_connection_execute_non_select_command (GdaConnection *cnc
,const gchar *sql
,GError **error
); gboolean gda_connection_insert_row_into_table (GdaConnection *cnc
,const gchar *table
,GError **error
,...
); gboolean gda_connection_insert_row_into_table_v (GdaConnection *cnc
,const gchar *table
,GSList *col_names
,GSList *values
,GError **error
); gboolean gda_connection_update_row_in_table (GdaConnection *cnc
,const gchar *table
,const gchar *condition_column_name
,GValue *condition_value
,GError **error
,...
); gboolean gda_connection_update_row_in_table_v (GdaConnection *cnc
,const gchar *table
,const gchar *condition_column_name
,GValue *condition_value
,GSList *col_names
,GSList *values
,GError **error
); gboolean gda_connection_delete_row_from_table (GdaConnection *cnc
,const gchar *table
,const gchar *condition_column_name
,GValue *condition_value
,GError **error
);
"auth-string" gchar* : Read / Write "cnc-string" gchar* : Read / Write "dsn" gchar* : Read / Write "events-history-size" gint : Read / Write "execution-timer" gboolean : Read / Write "is-wrapper" gboolean : Read / Write / Construct Only "meta-store" GdaMetaStore* : Read / Write "monitor-wrapped-in-mainloop" gboolean : Read / Write "options" GdaConnectionOptions : Read / Write "provider" GdaServerProvider* : Read / Write "thread-owner" gpointer : Read / Write
"conn-closed" :Run Last
"conn-opened" :Run First
"conn-to-close" :Run First
"dsn-changed" :Run Last
"error" :Run Last
"transaction-status-changed" :Run Last
Each connection to a database is represented by a GdaConnection object. A connection is created (and opened)
using gda_connection_open_from_dsn()
if a data source has been defined, or gda_connection_open_from_string()
otherwise.
It is not recommended to create a GdaConnection object using g_object_new()
as the results are unpredictable (some
parts won't correctly be initialized).
Use the connection object to execute statements, use transactions, get meta data information, ...
If supported by the database provider being used, statements can be executed asynchronously instead of blocking the execution thread untill the execution of a statement is finished. Each database provider is free to implement this feature as it wishes (using the API or using threads). The steps involved to execute a statement are then:
Request the statement execution using
gda_connection_async_statement_execute()
which returns an
execution ID to be used to identify a specific request
Do some useful things (that is why async. statements' excution are for)
Use one or more times
gda_connection_async_fetch_result()
to see
if the execution is finished, using the request ID
Use gda_connection_async_cancel()
to cancel
the execution of a statement
The GdaConnection object implements its own locking mechanism so it is thread-safe. However ad some database
providers rely on an API which does not support threads or supports it only partially, the connections
opened using those providers will only be accessible from the thread which created them (any other thread will
be blocked trying to access the connection, use the
gda_lockable_try_lock()
If a connection really needs to be accessed by several threads at once, then it is possible to pass the GDA_CONNECTION_OPTIONS_THREAD_SAFE flag when opening it. This flag requests that the real connection be created and really accessed in a private sub thread.
typedef enum { GDA_CONNECTION_OPTIONS_NONE = 0, GDA_CONNECTION_OPTIONS_READ_ONLY = 1 << 0, GDA_CONNECTION_OPTIONS_SQL_IDENTIFIERS_CASE_SENSITIVE = 1 << 1, GDA_CONNECTION_OPTIONS_THREAD_SAFE = 1 << 2, GDA_CONNECTION_OPTIONS_THREAD_ISOLATED = 1 << 3, GDA_CONNECTION_OPTIONS_AUTO_META_DATA = 1 << 4 } GdaConnectionOptions;
Specifies some aspects of a connection when opening it.
Additional information about the GDA_CONNECTION_OPTIONS_SQL_IDENTIFIERS_CASE_SENSITIVE flag:
For example without this flag, if the table name specified in a GdaServerOperation to create a table is MyTable, then usually the database will create a table named mytable, whereas with this flag, the table will be created as MyTable (note that in the end the database may still decide to name the table mytable or differently if it can't do otherwise).
Libgda will not apply this rule when parsing SQL code, the SQL code being parsed has to be conform to the database it will be used with
Additional information about the GDA_CONNECTION_OPTIONS_THREAD_SAFE and GDA_CONNECTION_OPTIONS_THREAD_ISOLATED flags: The GDA_CONNECTION_OPTIONS_THREAD_SAFE flag specifies that it has to be able to use the returned connection object from several threads at once (locking is ensured by the GdaConnection itself). Depending on the database provider's implementation and on the native libraries it uses, the "normal" connection object might not respect this requirement, and in this case a specific thread is started and used as the unique thread which will manipulate the actual connection, while a "wrapper connection" is actually returned and used by the caller (that wrapper connection passes method calls from the calling thread to the actual connection's specific thread, and gets the results back).
The GDA_CONNECTION_OPTIONS_THREAD_ISOLATED forces using a specific thread and a "wrapper connection" even if the
"normal" connection would itself be thread safe; this is useful for example to be sure the asynchronous API can
always be used (see gda_connection_async_statement_execute()
).
Having a specific thread and a "wrapper connection" definitely has an impact on the performances (because it involves messages passing between threads for every method call), so using the GDA_CONNECTION_OPTIONS_THREAD_SAFE or GDA_CONNECTION_OPTIONS_THREAD_ISOLATED flags should be carefully considered.
Note about the GDA_CONNECTION_OPTIONS_AUTO_META_DATA
flag:
Every time a DDL statement is successfully executed, the associated mate data, if defined, will be updated, which has a impact on performances
If a transaction is started and some DDL statements are executed and the transaction is not rolled back or committed, then the meta data may end up being wrong
no specific aspect | |
this flag specifies that the connection to open should be in a read-only mode (this policy is not correctly enforced at the moment) | |
this flag specifies that SQL identifiers submitted as input to Libgda have to keep their case sensitivity. | |
this flag specifies that the connection to open will be used by several threads at once so it has to be thread safe | |
this flag specifies that the connection to open will be used by several threads at once and requests that the real connection be used only in a sub thread created specifically for it | |
this flags specifies that if a GdaMetaStore has been associated to the connection, then it is kept up to date with the evolutions in the database's structure. Be aware however that there are some drawbacks explained below. |
typedef enum { GDA_CONNECTION_DSN_NOT_FOUND_ERROR, GDA_CONNECTION_PROVIDER_NOT_FOUND_ERROR, GDA_CONNECTION_PROVIDER_ERROR, GDA_CONNECTION_NO_CNC_SPEC_ERROR, GDA_CONNECTION_NO_PROVIDER_SPEC_ERROR, GDA_CONNECTION_OPEN_ERROR, GDA_CONNECTION_STATEMENT_TYPE_ERROR, GDA_CONNECTION_CANT_LOCK_ERROR, GDA_CONNECTION_TASK_NOT_FOUND_ERROR, GDA_CONNECTION_UNSUPPORTED_THREADS_ERROR, GDA_CONNECTION_CLOSED_ERROR, GDA_CONNECTION_META_DATA_CONTEXT_ERROR } GdaConnectionError;
GdaConnection * gda_connection_open_from_dsn (const gchar *dsn
,const gchar *auth_string
,GdaConnectionOptions options
,GError **error
);
This function is the way of opening database connections with libgda, using a pre-defined data source (DSN),
see gda_config_define_dsn()
for more information about how to define a DSN. If you don't want to define
a DSN, it is possible to use gda_connection_open_from_string()
instead of this method.
The dsn
string must have the following format: "[<username>[:<password>]@]<DSN>"
(if <username> and/or <password> are provided, and auth_string
is NULL
, then these username
and passwords will be used). Note that if provided, <username> and <password>
must be encoded as per RFC 1738, see gda_rfc1738_encode()
for more information.
The auth_string
can contain the authentication information for the server
to accept the connection. It is a string containing semi-colon seperated named value, usually
like "USERNAME=...;PASSWORD=..." where the ... are replaced by actual values. Note that each
name and value must be encoded as per RFC 1738, see gda_rfc1738_encode()
for more information.
The actual named parameters required depend on the provider being used, and that list is available
as the auth_params
member of the GdaProviderInfo structure for each installed
provider (use gda_config_get_provider_info()
to get it). Also one can use the "gda-sql-4.0 -L" command to
list the possible named parameters.
This method may fail with a GDA_CONNECTION_ERROR domain error (see the GdaConnectionError error codes)
or a GDA_CONFIG_ERROR
domain error (see the GdaConfigError error codes).
|
data source name. |
|
authentication string, or NULL . [allow-none]
|
|
options for the connection (see GdaConnectionOptions). |
|
a place to store an error, or NULL
|
Returns : |
a new GdaConnection if connection opening was successful or NULL if there was an error. [transfer full]
|
GdaConnection * gda_connection_open_from_string (const gchar *provider_name
,const gchar *cnc_string
,const gchar *auth_string
,GdaConnectionOptions options
,GError **error
);
Opens a connection given a provider ID and a connection string. This
allows applications to open connections without having to create
a data source (DSN) in the configuration. The format of cnc_string
is
similar to PostgreSQL and MySQL connection strings. It is a semicolumn-separated
series of <key>=<value> pairs, where each key and value are encoded as per RFC 1738,
see gda_rfc1738_encode()
for more information.
The possible keys depend on the provider, the "gda-sql-4.0 -L" command can be used to list the actual keys for each installed database provider.
For example the connection string to open an SQLite connection to a database
file named "my_data.db" in the current directory would be "DB_DIR=.;DB_NAME=my_data"
.
The cnc_string
string must have the following format:
"[<provider>://][<username>[:<password>]@]<connection_params>"
(if <username> and/or <password> are provided, and auth_string
is NULL
, then these username
and passwords will be used, and if <provider> is provided and provider_name
is NULL
then this
provider will be used). Note that if provided, <username>, <password> and <provider>
must be encoded as per RFC 1738, see gda_rfc1738_encode()
for more information.
The auth_string
must contain the authentication information for the server
to accept the connection. It is a string containing semi-colon seperated named values, usually
like "USERNAME=...;PASSWORD=..." where the ... are replaced by actual values. Note that each
name and value must be encoded as per RFC 1738, see gda_rfc1738_encode()
for more information.
The actual named parameters required depend on the provider being used, and that list is available
as the auth_params
member of the GdaProviderInfo structure for each installed
provider (use gda_config_get_provider_info()
to get it). Similarly to the format of the connection
string, use the "gda-sql-4.0 -L" command to list the possible named parameters.
Additionally, it is possible to have the connection string
respect the "<provider_name>://<real cnc string>" format, in which case the provider name
and the real connection string will be extracted from that string (note that if provider_name
is not NULL
then it will still be used as the provider ID).\
This method may fail with a GDA_CONNECTION_ERROR domain error (see the GdaConnectionError error codes)
or a GDA_CONFIG_ERROR
domain error (see the GdaConfigError error codes).
|
provider ID to connect to, or NULL . [allow-none]
|
|
connection string. |
|
authentication string, or NULL . [allow-none]
|
|
options for the connection (see GdaConnectionOptions). |
|
a place to store an error, or NULL
|
Returns : |
a new GdaConnection if connection opening was successful or NULL if there was an error. [transfer full]
|
gboolean gda_connection_open (GdaConnection *cnc
,GError **error
);
Tries to open the connection.
|
a GdaConnection object |
|
a place to store errors, or NULL
|
Returns : |
TRUE if the connection is opened, and FALSE otherwise. |
void gda_connection_close (GdaConnection *cnc
);
Closes the connection to the underlying data source, but first emits the "conn-to-close" signal.
|
a GdaConnection object. |
void gda_connection_close_no_warning (GdaConnection *cnc
);
Closes the connection to the underlying data source, without emiting any warning signal.
|
a GdaConnection object. |
gboolean gda_connection_is_opened (GdaConnection *cnc
);
Checks whether a connection is open or not.
|
a GdaConnection object. |
Returns : |
TRUE if the connection is open, FALSE if it's not. |
GdaSqlParser * gda_connection_create_parser (GdaConnection *cnc
);
Creates a new parser object able to parse the SQL dialect understood by cnc
.
If the GdaServerProvider object internally used by cnc
does not have its own parser,
then NULL
is returned, and a general SQL parser can be obtained
using gda_sql_parser_new()
.
|
a GdaConnection object |
Returns : |
a new GdaSqlParser object, or NULL . [transfer full]
|
gchar * gda_connection_value_to_sql_string (GdaConnection *cnc
,GValue *from
);
Produces a fully quoted and escaped string from a GValue
|
a GdaConnection object. |
|
GValue to convert from |
Returns : |
escaped and quoted value or NULL if not supported. |
gchar * gda_connection_quote_sql_identifier (GdaConnection *cnc
,const gchar *id
);
Use this method to get a correctly quoted (if necessary) SQL identifier which can be used
in SQL statements, from id
. If id
is already correctly quoted for cnc
, then a copy of id
may be returned.
This method may add double quotes (or other characters) around id
:
if id
is a reserved SQL keyword (such as SELECT, INSERT, ...)
if id
contains non allowed characters such as spaces, or if it starts with a digit
in any other event as necessary for cnc
, depending on the the options passed when opening the cnc
connection, and specifically the
GDA_CONNECTION_OPTIONS_SQL_IDENTIFIERS_CASE_SENSITIVE option.
One can safely pass an already quoted id
to this method, either with quoting characters allowed by cnc
or using the
double quote (") character.
|
a GdaConnection object |
|
an SQL identifier |
Returns : |
a new string, to free with g_free() once not needed anymore |
Since 4.0.3
gchar * gda_connection_statement_to_sql (GdaConnection *cnc
,GdaStatement *stmt
,GdaSet *params
,GdaStatementSqlFlag flags
,GSList **params_used
,GError **error
);
Renders stmt
as an SQL statement, adapted to the SQL dialect used by cnc
|
a GdaConnection object |
|
a GdaStatement object |
|
a GdaSet object (which can be obtained using gda_statement_get_parameters() ), or NULL . [allow-none]
|
|
SQL rendering flags, as GdaStatementSqlFlag OR'ed values |
|
a place to store the list of individual GdaHolder objects within params which have been used. [allow-none][element-type Gda.Holder][out][transfer container]
|
|
a place to store errors, or NULL
|
Returns : |
a new string, or NULL if an error occurred |
gboolean gda_connection_statement_prepare (GdaConnection *cnc
,GdaStatement *stmt
,GError **error
);
Ask the database accessed through the cnc
connection to prepare the usage of stmt
. This is only useful
if stmt
will be used more than once (however some database providers may always prepare statements
before executing them).
This function is also useful to make sure stmt
is fully understood by the database before actually executing it.
Note however that it is also possible that gda_connection_statement_prepare()
fails when
gda_connection_statement_execute()
does not fail (this will usually be the case with statements such as
"SELECT * FROM ##tablename::string" because database usually don't allow variables to be used in place of a
table name).
|
a GdaConnection |
|
a GdaStatement object |
|
a place to store errors, or NULL
|
Returns : |
TRUE if no error occurred. |
GObject * gda_connection_statement_execute (GdaConnection *cnc
,GdaStatement *stmt
,GdaSet *params
,GdaStatementModelUsage model_usage
,GdaSet **last_insert_row
,GError **error
);
Executes stmt
.
As stmt
can, by desing (and if not abused), contain only one SQL statement, the
return object will either be:
a GdaDataSelect object (which is also a GdaDataModel) if stmt
is a SELECT statement
(usually a GDA_SQL_STATEMENT_SELECT, see GdaSqlStatementType)
containing the results of the SELECT. The resulting data model is by default read only, but
modifications can be enabled, see the GdaDataSelect's documentation for more information.
a GdaSet for any other SQL statement which correctly executed. In this case (if the provider supports it), then the GdaSet may contain value holders named:
a (gint) GdaHolder named "IMPACTED_ROWS"
a (GObject) GdaHolder named "EVENT" which contains a GdaConnectionEvent
If last_insert_row
is not NULL
and stmt
is an INSERT statement, then it will contain (if the
provider used by cnc
supports it) a new GdaSet object composed of value holders named "+<column number>"
starting at column 0 which contain the actual inserted values. For example if a table is composed of an 'id' column
which is auto incremented and a 'name' column then the execution of a "INSERT INTO mytable (name) VALUES ('joe')"
query will return a GdaSet with two holders:
one with the '+0' ID which may for example contain 1 (note that its "name" property should be "id")
one with the '+1' ID which will contain 'joe' (note that its "name" property should be "name")
This method may fail with a GDA_SERVER_PROVIDER_ERROR
domain error (see the GdaServerProviderError error codes).
Note1: If stmt
is a SELECT statement which has some parameters and if params
is NULL
, then the statement can't
be executed and this method will return NULL
.
Note2: If stmt
is a SELECT statement which has some parameters and if params
is not NULL
but contains some
invalid parameters, then the statement can't be executed and this method will return NULL
, unless the
model_usage
has the GDA_STATEMENT_MODEL_ALLOW_NOPARAM flag.
Note3: If stmt
is a SELECT statement which has some parameters and if params
is not NULL
but contains some
invalid parameters and if model_usage
has the GDA_STATEMENT_MODEL_ALLOW_NOPARAM flag, then the returned
data model will contain no row but will have all the correct columns (even though some of the columns might
report as GDA_TYPE_NULL). In this case, if (after this method call) any of params
' parameters change
then the resulting data model will re-run itself, see the GdaDataSelect's
auto-reset property for more information.
Note4: if model_usage
does not contain the GDA_STATEMENT_MODEL_RANDOM_ACCESS or
GDA_STATEMENT_MODEL_CURSOR_FORWARD flags, then the default will be to return a random access data model
Note5: If stmt
is a SELECT statement which returns blob values (of type GDA_TYPE_BLOB
), then an implicit
transaction will have been started by the database provider, and it's up to the caller to close the transaction
(which will then be locked) once all the blob ressources have been
liberated (when the returned data model is destroyed). See the section about
Binary large objects (BLOBs) for more information.
Also see the provider's limitations, and the Advanced GdaDataSelect usage sections.
|
a GdaConnection |
|
a GdaStatement object |
|
a GdaSet object (which can be obtained using gda_statement_get_parameters() ), or NULL . [allow-none]
|
|
in the case where stmt is a SELECT statement, specifies how the returned data model will be used |
|
a place to store a new GdaSet object which contains the values of the last inserted row, or NULL . [out][transfer full][allow-none]
|
|
a place to store errors, or NULL
|
Returns : |
a GObject, or NULL if an error occurred. [transfer full]
|
GdaDataModel * gda_connection_statement_execute_select (GdaConnection *cnc
,GdaStatement *stmt
,GdaSet *params
,GError **error
);
Executes a selection command on the given connection. The gda_execute_select_command()
method can be easier
to use if one prefers to use some SQL directly.
This function returns a GdaDataModel resulting from the SELECT statement, or NULL
if an error occurred.
This function is just a convenience function around the gda_connection_statement_execute()
function.
See the documentation of the gda_connection_statement_execute()
for information
about the params
list of parameters.
|
a GdaConnection object. |
|
a GdaStatement object. |
|
a GdaSet object (which can be obtained using gda_statement_get_parameters() ), or NULL . [allow-none]
|
|
a place to store an error, or NULL
|
Returns : |
a GdaDataModel containing the data returned by the
data source, or NULL if an error occurred. [transfer full]
|
GdaDataModel * gda_connection_statement_execute_select_full (GdaConnection *cnc
,GdaStatement *stmt
,GdaSet *params
,GdaStatementModelUsage model_usage
,GType *col_types
,GError **error
);
Executes a selection command on the given connection.
This function returns a GdaDataModel resulting from the SELECT statement, or NULL
if an error occurred.
This function is just a convenience function around the gda_connection_statement_execute()
function.
See the documentation of the gda_connection_statement_execute()
for information
about the params
list of parameters.
|
a GdaConnection object. |
|
a GdaStatement object. |
|
a GdaSet object (which can be obtained using gda_statement_get_parameters() ), or NULL . [allow-none]
|
|
specifies how the returned data model will be used as a GdaStatementModelUsage enum |
|
an array of GType to request each returned GdaDataModel's column's GType, terminated with the G_TYPE_NONE
value. Any value left to 0 will make the database provider determine the real GType. col_types can also be NULL if no
column type is specified. [array][allow-none]
|
|
a place to store an error, or NULL
|
Returns : |
a GdaDataModel containing the data returned by the
data source, or NULL if an error occurred. [transfer full]
|
GdaDataModel * gda_connection_statement_execute_select_fullv (GdaConnection *cnc
,GdaStatement *stmt
,GdaSet *params
,GdaStatementModelUsage model_usage
,GError **error
,...
);
Executes a selection command on the given connection.
This function returns a GdaDataModel resulting from the SELECT statement, or NULL
if an error occurred.
This function is just a convenience function around the gda_connection_statement_execute()
function.
See the documentation of the gda_connection_statement_execute()
for information
about the params
list of parameters.
|
a GdaConnection object. |
|
a GdaStatement object. |
|
a GdaSet object (which can be obtained using gda_statement_get_parameters() ), or NULL . [allow-none]
|
|
specifies how the returned data model will be used as a GdaStatementModelUsage enum |
|
a place to store an error, or NULL
|
|
a (-1 terminated) list of (column number, GType) specifying for each column mentioned the GType of the column in the returned GdaDataModel. |
Returns : |
a GdaDataModel containing the data returned by the
data source, or NULL if an error occurred. [transfer full]
|
gint gda_connection_statement_execute_non_select (GdaConnection *cnc
,GdaStatement *stmt
,GdaSet *params
,GdaSet **last_insert_row
,GError **error
);
Executes a non-selection statement on the given connection. The gda_execute_non_select_command()
method can be easier
to use if one prefers to use some SQL directly.
This function returns the number of rows affected by the execution of stmt
, or -1
if an error occurred, or -2 if the connection's provider does not return the number of rows affected.
This function is just a convenience function around the gda_connection_statement_execute()
function.
See the documentation of the gda_connection_statement_execute()
for information
about the params
list of parameters.
See gda_connection_statement_execute()
form more information about last_insert_row
.
|
a GdaConnection object. |
|
a GdaStatement object. |
|
a GdaSet object (which can be obtained using gda_statement_get_parameters() ), or NULL . [allow-none]
|
|
a place to store a new GdaSet object which contains the values of the last inserted row, or NULL . [out][transfer full][allow-none]
|
|
a place to store an error, or NULL
|
Returns : |
the number of rows affected (>=0) or -1 or -2 |
GSList * gda_connection_repetitive_statement_execute (GdaConnection *cnc
,GdaRepetitiveStatement *rstmt
,GdaStatementModelUsage model_usage
,GType *col_types
,gboolean stop_on_error
,GError **error
);
Executes the statement upon which rstmt
is built. Note that as several statements can actually be executed by this
method, it is recommended to be within a transaction.
If error
is not NULL
and stop_on_error
is FALSE
, then it may contain the last error which occurred.
|
a GdaConnection |
|
a GdaRepetitiveStatement object |
|
specifies how the returned data model will be used as a GdaStatementModelUsage enum |
|
an array of GType to request each returned GdaDataModel's column's GType, see gda_connection_statement_execute_select_full() for more information. [array][allow-none]
|
|
set to TRUE if the method has to stop on the first error. |
|
a place to store errors, or NULL
|
Returns : |
a new list of GObject pointers (see gda_connection_statement_execute() for more information about what they
represent), one for each actual execution of the statement upon which rstmt is built. If stop_on_error is FALSE , then
the list may contain some NULL pointers which refer to statements which failed to execute. [transfer full][element-type GObject]
|
Since 4.2
GSList * gda_connection_batch_execute (GdaConnection *cnc
,GdaBatch *batch
,GdaSet *params
,GdaStatementModelUsage model_usage
,GError **error
);
Executes all the statements contained in batch
(in the order in which they were added to batch
), and
returns a list of GObject objects, at most one GObject for each statement; see gda_connection_statement_execute()
for details about the returned objects.
If one of the statement fails, then none of the subsequent statement will be executed, and the method returns the list of GObject created by the correct execution of the previous statements. If a transaction is required, then it should be started before calling this method.
|
a GdaConnection object |
|
a GdaBatch object which contains all the statements to execute |
|
a GdaSet object (which can be obtained using gda_batch_get_parameters() ), or NULL . [allow-none]
|
|
specifies how the returned data model(s) will be used, as a GdaStatementModelUsage enum |
|
a place to store errors, or NULL
|
Returns : |
a new list of GObject objects. [transfer full][element-type GObject] |
gboolean gda_connection_begin_transaction (GdaConnection *cnc
,const gchar *name
,GdaTransactionIsolation level
,GError **error
);
Starts a transaction on the data source, identified by the
name
parameter.
Before starting a transaction, you can check whether the underlying
provider does support transactions or not by using the
gda_connection_supports_feature()
function.
|
a GdaConnection object. |
|
the name of the transation to start, or NULL . [allow-none]
|
|
the requested transaction level (GDA_TRANSACTION_ISOLATION_UNKNOWN if not specified) |
|
a place to store errors, or NULL
|
Returns : |
TRUE if the transaction was started successfully, FALSE
otherwise. |
gboolean gda_connection_commit_transaction (GdaConnection *cnc
,const gchar *name
,GError **error
);
Commits the given transaction to the backend database. You need to call
gda_connection_begin_transaction()
first.
|
a GdaConnection object. |
|
the name of the transation to commit, or NULL . [allow-none]
|
|
a place to store errors, or NULL
|
Returns : |
TRUE if the transaction was finished successfully,
FALSE otherwise. |
gboolean gda_connection_rollback_transaction (GdaConnection *cnc
,const gchar *name
,GError **error
);
Rollbacks the given transaction. This means that all changes
made to the underlying data source since the last call to
#gda_connection_begin_transaction()
or #gda_connection_commit_transaction()
will be discarded.
|
a GdaConnection object. |
|
the name of the transation to commit, or NULL . [allow-none]
|
|
a place to store errors, or NULL
|
Returns : |
TRUE if the operation was successful, FALSE otherwise. |
gboolean gda_connection_add_savepoint (GdaConnection *cnc
,const gchar *name
,GError **error
);
Adds a SAVEPOINT named name
.
|
a GdaConnection object |
|
name of the savepoint to add. [allow-none] |
|
a place to store errors or NULL
|
Returns : |
TRUE if no error occurred |
gboolean gda_connection_rollback_savepoint (GdaConnection *cnc
,const gchar *name
,GError **error
);
Rollback all the modifications made after the SAVEPOINT named name
.
|
a GdaConnection object |
|
name of the savepoint to rollback to. [allow-none] |
|
a place to store errors or NULL
|
Returns : |
TRUE if no error occurred |
gboolean gda_connection_delete_savepoint (GdaConnection *cnc
,const gchar *name
,GError **error
);
Delete the SAVEPOINT named name
when not used anymore.
|
a GdaConnection object |
|
name of the savepoint to delete. [allow-none] |
|
a place to store errors or NULL
|
Returns : |
TRUE if no error occurred |
guint gda_connection_async_statement_execute (GdaConnection *cnc
,GdaStatement *stmt
,GdaSet *params
,GdaStatementModelUsage model_usage
,GType *col_types
,gboolean need_last_insert_row
,GError **error
);
This method is similar to gda_connection_statement_execute()
but is asynchronous as it method returns
immediately with a task ID. It's up to the caller to use gda_connection_async_fetch_result()
regularly to check
if the statement's execution is finished.
It is possible to call the method several times to request several statements to be executed asynchronously, the statements will be executed in the order in which they were requested.
The parameters, if present, are copied and can be discarded or modified before the statement is actually executed.
The stmt
object is not copied but simply referenced (for performance reasons), and if it is modified before
it is actually executed, then its execution will not occur. It is however safe to call g_object_unref()
on it if
it's not needed anymore.
The execution failure of any statement has no impact on the execution of other statements except for example if the connection has a transaction started and the failure invalidates the transaction (as decided by the database server).
|
a GdaConnection |
|
a GdaStatement object |
|
a GdaSet object (which can be obtained using gda_statement_get_parameters() ), or NULL . [allow-none]
|
|
in the case where stmt is a SELECT statement, specifies how the returned data model will be used |
|
an array of GType to request each returned GdaDataModel's column's GType, terminated with the G_TYPE_NONE. [array][allow-none] |
|
TRUE if the values of the last interted row must be computed |
|
a place to store errors, or NULL
|
Returns : |
a task ID, or 0 if an error occurred (not an error regarding stmt itself as its execution has not yet started
but any other error) |
Since 4.2
GObject * gda_connection_async_fetch_result (GdaConnection *cnc
,guint task_id
,GdaSet **last_insert_row
,GError **error
);
Use this method to obtain the result of the execution of a statement which has been executed asynchronously by
calling gda_connection_async_statement_execute()
. This function is non locking and will return NULL
(and no
error will be set) if the statement has not been executed yet.
If the statement has been executed, this method returns the same value as gda_connection_statement_execute()
would have if the statement had been
executed synchronously.
|
a GdaConnection |
|
a task ID returned by gda_connection_async_statement_execute()
|
|
a place to store a new GdaSet object which contains the values of the last inserted row, or NULL . [out][transfer full][allow-none]
|
|
a place to store errors, or NULL
|
Returns : |
a GObject, or NULL if an error occurred. [transfer full]
|
Since 4.2
gboolean gda_connection_async_cancel (GdaConnection *cnc
,guint task_id
,GError **error
);
Requests that a task be cancelled. This operation may of may not have any effect
depending on the task's status, even if it returns TRUE
. If it returns FALSE
,
then the task has not been cancelled.
|
a GdaConnection |
|
a task ID returned by gda_connection_async_statement_execute()
|
|
a place to store errors, or NULL
|
Returns : |
TRUE if no error occurred |
Since 4.2
GdaTransactionStatus * gda_connection_get_transaction_status
(GdaConnection *cnc
);
Get the status of cnc
regarding transactions. The returned object should not be modified
or destroyed; however it may be modified or destroyed by the connection itself.
If NULL
is returned, then no transaction has been associated with cnc
|
a GdaConnection object |
Returns : |
a GdaTransactionStatus object, or NULL . [transfer none]
|
GdaConnectionOptions gda_connection_get_options (GdaConnection *cnc
);
Gets the GdaConnectionOptions used to open this connection.
|
a GdaConnection object. |
Returns : |
the connection options. |
GdaServerProvider * gda_connection_get_provider (GdaConnection *cnc
);
Gets a pointer to the GdaServerProvider object used to access the database
|
a GdaConnection object |
Returns : |
the GdaServerProvider (NEVER NULL). [transfer none] |
const gchar * gda_connection_get_provider_name (GdaConnection *cnc
);
Gets the name (identifier) of the database provider used by cnc
|
a GdaConnection object |
Returns : |
a non modifiable string |
const gchar * gda_connection_get_dsn (GdaConnection *cnc
);
|
a GdaConnection object |
Returns : |
the data source name the connection object is connected to. |
const gchar * gda_connection_get_cnc_string (GdaConnection *cnc
);
Gets the connection string used to open this connection.
The connection string is the string sent over to the underlying database provider, which describes the parameters to be used to open a connection on the underlying data source.
|
a GdaConnection object. |
Returns : |
the connection string used when opening the connection. |
const gchar * gda_connection_get_authentication (GdaConnection *cnc
);
Gets the user name used to open this connection.
|
a GdaConnection object. |
Returns : |
the user name. |
const GList * gda_connection_get_events (GdaConnection *cnc
);
Retrieves a list of the last errors occurred during the connection. The returned list is chronologically ordered such as that the most recent event is the GdaConnectionEvent of the first node.
Warning: the cnc
object may change the list if connection events occur
|
a GdaConnection. |
Returns : |
a GList of GdaConnectionEvent objects (the list should not be modified). [transfer none][element-type Gda.ConnectionEvent] |
GdaServerOperation * gda_connection_create_operation (GdaConnection *cnc
,GdaServerOperationType type
,GdaSet *options
,GError **error
);
Creates a new GdaServerOperation object which can be modified in order
to perform the type type of action. It is a wrapper around the gda_server_provider_create_operation()
method.
|
a GdaConnection object |
|
the type of operation requested |
|
an optional list of parameters. [allow-none] |
|
a place to store an error, or NULL
|
Returns : |
a new GdaServerOperation object, or NULL in the connection's provider does not support the type type
of operation or if an error occurred. [transfer full]
|
gboolean gda_connection_perform_operation (GdaConnection *cnc
,GdaServerOperation *op
,GError **error
);
Performs the operation described by op
(which should have been created using
gda_connection_create_operation()
). It is a wrapper around the gda_server_provider_perform_operation()
method.
|
a GdaConnection object |
|
a GdaServerOperation object |
|
a place to store an error, or NULL
|
Returns : |
TRUE if no error occurred |
typedef enum { GDA_CONNECTION_FEATURE_AGGREGATES, GDA_CONNECTION_FEATURE_BLOBS, GDA_CONNECTION_FEATURE_INDEXES, GDA_CONNECTION_FEATURE_INHERITANCE, GDA_CONNECTION_FEATURE_NAMESPACES, GDA_CONNECTION_FEATURE_PROCEDURES, GDA_CONNECTION_FEATURE_SEQUENCES, GDA_CONNECTION_FEATURE_SQL, GDA_CONNECTION_FEATURE_TRANSACTIONS, GDA_CONNECTION_FEATURE_SAVEPOINTS, GDA_CONNECTION_FEATURE_SAVEPOINTS_REMOVE, GDA_CONNECTION_FEATURE_TRIGGERS, GDA_CONNECTION_FEATURE_UPDATABLE_CURSOR, GDA_CONNECTION_FEATURE_USERS, GDA_CONNECTION_FEATURE_VIEWS, GDA_CONNECTION_FEATURE_XA_TRANSACTIONS, GDA_CONNECTION_FEATURE_MULTI_THREADING, GDA_CONNECTION_FEATURE_LAST } GdaConnectionFeature;
Used in gda_connection_supports_feature()
and gda_server_provider_supports_feature()
to test if a connection
or a database provider supports some specific feature.
test for aggregates support | |
test for BLOBS (binary large objects) support | |
test for indexes support | |
test for tables inheritance support | |
test for namespaces support | |
test for functions support | |
test for sequences support | |
test for SQL language (even specific to the database) support | |
test for transactions support | |
test for savepoints within transactions support | |
test if savepoints can be removed | |
test for triggers support | |
test for updatable cursors support | |
test for users support | |
test for views support | |
test for distributed transactions support | |
test for native multi-threading support | |
not used |
gboolean gda_connection_supports_feature (GdaConnection *cnc
,GdaConnectionFeature feature
);
Asks the underlying provider for if a specific feature is supported.
|
a GdaConnection object. |
|
feature to ask for. |
Returns : |
TRUE if the provider supports it, FALSE if not. |
GdaMetaStore * gda_connection_get_meta_store (GdaConnection *cnc
);
Get or initializes the GdaMetaStore associated to cnc
|
a GdaConnection object |
Returns : |
a GdaMetaStore object. [transfer none] |
gboolean gda_connection_update_meta_store (GdaConnection *cnc
,GdaMetaContext *context
,GError **error
);
Updates cnc
's associated GdaMetaStore. If context
is not NULL
, then only the parts described by
context
will be updated, and if it is NULL
, then the complete meta store will be updated. Detailed
explanations follow:
In order to keep the meta store's contents in a consistent state, the update process involves updating the contents of all the tables related to one where the contents change. For example the "_columns" table (which lists all the columns of a table) depends on the "_tables" table (which lists all the tables in a schema), so if a row is added, removed or modified in the "_tables", then the "_columns" table's contents needs to be updated as well regarding that row.
If context
is NULL
, then the update process will simply overwrite any data that was present in all the
meta store's tables with new (up to date) data even if nothing has changed, without having to build the
tables' dependency tree. This is the recommended way of proceeding when dealing with a meta store which
might be outdated.
On the other hand, if context
is not NULL
, then a tree of the dependencies has to be built (depending on
context
) and only some parts of the meta store are updated following that dependencies tree. Specifying a
context may be useful for example in the following situations:
One knows that a database object has changed (for example a table created), and
may use the context
to request that only the information about that table be updated
One is only interested in the list of views, and may request that only the information about views may be updated
When context
is not NULL
, and contains specified SQL identifiers (for example the "table_name" of the "_tables"
table), then each SQL identifier has to match the convention the GdaMetaStore has adopted regarding
case sensitivity, using gda_connection_quote_sql_identifier()
or gda_meta_store_sql_identifier_quote()
.
see the
meta data section about SQL identifiers for more information, and the documentation about the
gda_sql_identifier_quote()
function which will be most useful.
Note however that usually more information will be updated than strictly requested by
the context
argument.
For more information, see the Database structure section, and the Update the meta data about a table howto.
|
a GdaConnection object. |
|
description of which part of cnc 's associated GdaMetaStore should be updated, or NULL . [allow-none]
|
|
a place to store errors, or NULL
|
Returns : |
TRUE if no error occurred |
typedef enum { GDA_CONNECTION_META_NAMESPACES, GDA_CONNECTION_META_TYPES, GDA_CONNECTION_META_TABLES, GDA_CONNECTION_META_VIEWS, GDA_CONNECTION_META_FIELDS, GDA_CONNECTION_META_INDEXES } GdaConnectionMetaType;
Used with gda_connection_get_meta_store_data()
to describe what meta data to extract from
a connection's associated GdaMetaStore.
lists the namespaces (or schemas for PostgreSQL) | |
lists the database types | |
lists the tables | |
lists the views | |
lists the table's or view's fields | |
lists the table's indexes |
GdaDataModel * gda_connection_get_meta_store_data (GdaConnection *cnc
,GdaConnectionMetaType meta_type
,GError **error
,gint nb_filters
,...
);
Retrieves data stored in cnc
's associated GdaMetaStore object. This method is useful
to easily get some information about the meta-data associated to cnc
, such as the list of
tables, views, and other database objects.
Note: it's up to the caller to make sure the information contained within cnc
's associated GdaMetaStore
is up to date using gda_connection_update_meta_store()
(it can become outdated if the database's schema
is modified).
For more information about the returned data model's attributes, or about the meta_type
and ... filter arguments,
see this description.
Also, when using filters involving data which are SQL identifiers, make sure each SQL identifier
is represented using the GdaMetaStore convention, using gda_meta_store_sql_identifier_quote()
or
gda_meta_store_sql_identifier_quote()
.
See the
meta data section about SQL identifiers for more information, and the documentation about the
gda_sql_identifier_quote()
function which will be most useful.
|
a GdaConnection object. |
|
describes which data to get. |
|
a place to store errors, or NULL
|
|
the number of filters in the @... argument |
|
a list of (filter name (gchar *), filter value (GValue*)) pairs specifying
the filter to apply to the returned data model's contents (there must be nb_filters pairs) |
Returns : |
a GdaDataModel containing the data required. The caller is responsible
for freeing the returned model using g_object_unref() . [transfer full]
|
GdaDataModel * gda_connection_get_meta_store_data_v (GdaConnection *cnc
,GdaConnectionMetaType meta_type
,GList *filters
,GError **error
);
see gda_connection_get_meta_store_data
|
a GdaConnection object. |
|
describes which data to get. |
|
a GList of GdaHolder objects. [element-type GdaHolder] |
|
a place to store errors, or NULL
|
Returns : |
a GdaDataModel containing the data required. The caller is responsible
for freeing the returned model using g_object_unref() . [transfer full]
|
GdaStatement * gda_connection_parse_sql_string (GdaConnection *cnc
,const gchar *sql
,GdaSet **params
,GError **error
);
This function helps to parse a SQL string which uses parameters and store them at params
.
|
a GdaConnection object, or NULL . [allow-none]
|
|
an SQL command to parse, not NULL
|
|
a place to store a new GdaSet, for parameters used in SQL command, or NULL . [out][allow-none][transfer full]
|
|
a place to store errors, or NULL
|
Returns : |
a GdaStatement representing the SQL command, or NULL if an error occurred. [transfer full]
|
Since 4.2.3
GdaDataModel * gda_connection_execute_select_command (GdaConnection *cnc
,const gchar *sql
,GError **error
);
Execute a SQL SELECT command over an opened connection.
|
an opened connection |
|
a query statement that must begin with "SELECT" |
|
a place to store errors, or NULL
|
Returns : |
a new GdaDataModel if successful, NULL otherwise. [transfer full]
|
Since 4.2.3
gint gda_connection_execute_non_select_command (GdaConnection *cnc
,const gchar *sql
,GError **error
);
This is a convenience function to execute a SQL command over the opened connection. For the
returned value, see gda_connection_statement_execute_non_select()
's documentation.
|
an opened connection |
|
a query statement that must not begin with "SELECT" |
|
a place to store errors, or NULL
|
Returns : |
the number of rows affected or -1, or -2 |
Since 4.2.3
gboolean gda_connection_insert_row_into_table (GdaConnection *cnc
,const gchar *table
,GError **error
,...
);
This is a convenience function, which creates an INSERT statement and executes it using the values provided. It internally relies on variables which makes it immune to SQL injection problems.
The equivalent SQL command is: INSERT INTO <table> (<column_name> [,...]) VALUES (<column_name> = <new_value> [,...]).
|
an opened connection |
|
table's name to insert into |
|
a place to store errors, or NULL
|
|
a list of string/GValue pairs with the name of the column to use and the
GValue pointer containing the value to insert for the column (value can be NULL ), finished by a NULL . There must be
at least one column name and value |
Returns : |
TRUE if no error occurred |
Since 4.2.3
gboolean gda_connection_insert_row_into_table_v (GdaConnection *cnc
,const gchar *table
,GSList *col_names
,GSList *values
,GError **error
);
col_names
and values
must have length (>= 1).
This is a convenience function, which creates an INSERT statement and executes it using the values provided. It internally relies on variables which makes it immune to SQL injection problems.
The equivalent SQL command is: INSERT INTO <table> (<column_name> [,...]) VALUES (<column_name> = <new_value> [,...]).
|
an opened connection |
|
table's name to insert into |
|
a list of column names (as const gchar *). [element-type utf8] |
|
a list of values (as GValue). [element-type GValue] |
|
a place to store errors, or NULL
|
Returns : |
TRUE if no error occurred, FALSE otherwise |
Since 4.2.3
gboolean gda_connection_update_row_in_table (GdaConnection *cnc
,const gchar *table
,const gchar *condition_column_name
,GValue *condition_value
,GError **error
,...
);
This is a convenience function, which creates an UPDATE statement and executes it using the values provided. It internally relies on variables which makes it immune to SQL injection problems.
The equivalent SQL command is: UPDATE <table> SET <column_name> = <new_value> [,...] WHERE <condition_column_name> = <condition_value>.
|
an opened connection |
|
the table's name with the row's values to be updated |
|
the name of the column to used in the WHERE condition clause |
|
the condition_column_type 's GType |
|
a place to store errors, or NULL
|
|
a list of string/GValue pairs with the name of the column to use and the
GValue pointer containing the value to update the column to (value can be NULL ), finished by a NULL . There must be
at least one column name and value |
Returns : |
TRUE if no error occurred, FALSE otherwise |
Since 4.2.3
gboolean gda_connection_update_row_in_table_v (GdaConnection *cnc
,const gchar *table
,const gchar *condition_column_name
,GValue *condition_value
,GSList *col_names
,GSList *values
,GError **error
);
col_names
and values
must have length (>= 1).
This is a convenience function, which creates an UPDATE statement and executes it using the values provided. It internally relies on variables which makes it immune to SQL injection problems.
The equivalent SQL command is: UPDATE <table> SET <column_name> = <new_value> [,...] WHERE <condition_column_name> = <condition_value>.
|
an opened connection |
|
the table's name with the row's values to be updated |
|
the name of the column to used in the WHERE condition clause |
|
the condition_column_type 's GType |
|
a list of column names (as const gchar *). [element-type utf8] |
|
a list of values (as GValue). [element-type GValue] |
|
a place to store errors, or NULL
|
Returns : |
TRUE if no error occurred, FALSE otherwise |
Since 4.2.3
gboolean gda_connection_delete_row_from_table (GdaConnection *cnc
,const gchar *table
,const gchar *condition_column_name
,GValue *condition_value
,GError **error
);
This is a convenience function, which creates a DELETE statement and executes it using the values provided. It internally relies on variables which makes it immune to SQL injection problems.
The equivalent SQL command is: DELETE FROM <table> WHERE <condition_column_name> = <condition_value>.
|
an opened connection |
|
the table's name with the row's values to be updated |
|
the name of the column to used in the WHERE condition clause |
|
the condition_column_type 's GType |
|
a place to store errors, or NULL
|
Returns : |
TRUE if no error occurred, FALSE otherwise |
Since 4.2.3
"auth-string"
property "auth-string" gchar* : Read / Write
Authentication string to use.
Default value: NULL
"cnc-string"
property "cnc-string" gchar* : Read / Write
Connection string to use.
Default value: NULL
"events-history-size"
property "events-history-size" gint : Read / Write
Defines the number of GdaConnectionEvent objects kept in memory which can
be fetched using gda_connection_get_events()
.
Allowed values: >= 5
Default value: 5
Since 4.2
"execution-timer"
property "execution-timer" gboolean : Read / Write
Computes execution times for each statement executed.
Default value: FALSE
Since 4.2.9
"is-wrapper"
property "is-wrapper" gboolean : Read / Write / Construct Only
Tells if the connection acts as a thread wrapper around another connection, making it completely thread safe.
Default value: FALSE
Since 4.2
"meta-store"
property"meta-store" GdaMetaStore* : Read / Write
GdaMetaStore used by the connection.
"monitor-wrapped-in-mainloop"
property "monitor-wrapped-in-mainloop" gboolean : Read / Write
Useful only when there is a mainloop and when the connection acts as a thread wrapper around another connection, it sets up a timeout to handle signals coming from the wrapped connection.
If the connection is not a thread wrapper, then this property has no effect.
Default value: FALSE
Since 4.2
"conn-closed"
signalvoid user_function (GdaConnection *cnc,
gpointer user_data) : Run Last
Gets emitted when the connection to the database has been closed
|
the GdaConnection |
|
user data set when the signal handler was connected. |
"conn-opened"
signalvoid user_function (GdaConnection *cnc,
gpointer user_data) : Run First
Gets emitted when the connection has been opened to the database
|
the GdaConnection |
|
user data set when the signal handler was connected. |
"conn-to-close"
signalvoid user_function (GdaConnection *cnc,
gpointer user_data) : Run First
Gets emitted when the connection to the database is about to be closed
|
the GdaConnection |
|
user data set when the signal handler was connected. |
"dsn-changed"
signalvoid user_function (GdaConnection *cnc,
gpointer user_data) : Run Last
Gets emitted when the DSN used by cnc
has been changed
|
the GdaConnection |
|
user data set when the signal handler was connected. |
"error"
signalvoid user_function (GdaConnection *cnc,
GdaConnectionEvent *event,
gpointer user_data) : Run Last
Gets emitted whenever a connection event occurs. Check the nature of event
to
see if it's an error or a simple notification
|
the GdaConnection |
|
a GdaConnectionEvent object |
|
user data set when the signal handler was connected. |
"transaction-status-changed"
signalvoid user_function (GdaConnection *cnc,
gpointer user_data) : Run Last
Gets emitted when the transaction status of cnc
has changed (a transaction has been
started, rolled back, a savepoint added,...)
|
the GdaConnection |
|
user data set when the signal handler was connected. |