![]() |
![]() |
![]() |
GNOME Data Access 4 manual | ![]() |
---|---|---|---|---|
Top | Description | Object Hierarchy | Properties | Signals |
GdaStatement; enum GdaStatementSqlFlag; enum GdaStatementModelUsage; enum GdaStatementError; GdaStatement * gda_statement_new (void
); GdaStatement * gda_statement_copy (GdaStatement *orig
); gchar * gda_statement_serialize (GdaStatement *stmt
); gboolean gda_statement_get_parameters (GdaStatement *stmt
,GdaSet **out_params
,GError **error
); #define gda_statement_to_sql (stmt, params, error) gchar * gda_statement_to_sql_extended (GdaStatement *stmt
,GdaConnection *cnc
,GdaSet *params
,GdaStatementSqlFlag flags
,GSList **params_used
,GError **error
); GdaSqlStatementType gda_statement_get_statement_type (GdaStatement *stmt
); gboolean gda_statement_is_useless (GdaStatement *stmt
); gboolean gda_statement_check_structure (GdaStatement *stmt
,GError **error
); gboolean gda_statement_check_validity (GdaStatement *stmt
,GdaConnection *cnc
,GError **error
); gboolean gda_statement_normalize (GdaStatement *stmt
,GdaConnection *cnc
,GError **error
);
The GdaStatement represents a single SQL statement (multiple statements can be grouped in a GdaBatch object).
A GdaStatement can either be built by describing its constituing parts using a GdaSqlBuilder object, or from an SQL statement using a GdaSqlParser object.
A GdaConnection can use a GdaStatement to:
prepare it for a future execution, the preparation step involves converting the GdaStatement
object into a structure used by the database's own API, see gda_connection_statement_prepare()
execute it using gda_connection_statement_execute_select()
if it is known that the statement is a
selection statement, gda_connection_statement_execute_non_select()
if it is not a selection statement, or
gda_connection_statement_execute()
when the type of expected result is unknown.
Note that it is possible to use the same GdaStatement object at the same time with several GdaConnection objects.
typedef enum { GDA_STATEMENT_SQL_PARAMS_AS_VALUES = 0, GDA_STATEMENT_SQL_PRETTY = 1 << 0, GDA_STATEMENT_SQL_PARAMS_LONG = 1 << 1, GDA_STATEMENT_SQL_PARAMS_SHORT = 1 << 2, GDA_STATEMENT_SQL_PARAMS_AS_COLON = 1 << 3, GDA_STATEMENT_SQL_PARAMS_AS_DOLLAR = 1 << 4, GDA_STATEMENT_SQL_PARAMS_AS_QMARK = 1 << 5, GDA_STATEMENT_SQL_PARAMS_AS_UQMARK = 1 << 6 } GdaStatementSqlFlag;
Specifies how the general rendering is done
rendering will replace parameters with their values | |
rendering will include newlines and indentation to make it easy to read | |
parameters will be rendered using the "/* name:<param_name> ... */" syntax | |
parameters will be rendered using the "##<param_name>..." syntax | |
parameters will be rendered using the ":<param_name>" syntax | |
parameters will be rendered using the "$<param_number>" syntax where parameters are numbered starting from 1 | |
parameters will be rendered using the "?<param_number>" syntax where parameters are numbered starting from 1 | |
parameters will be rendered using the "?" syntax |
typedef enum { GDA_STATEMENT_MODEL_RANDOM_ACCESS = 1 << 0, GDA_STATEMENT_MODEL_CURSOR_FORWARD = 1 << 1, GDA_STATEMENT_MODEL_CURSOR_BACKWARD = 1 << 2, GDA_STATEMENT_MODEL_CURSOR = GDA_STATEMENT_MODEL_CURSOR_FORWARD | GDA_STATEMENT_MODEL_CURSOR_BACKWARD, GDA_STATEMENT_MODEL_ALLOW_NOPARAM = 1 << 3 } GdaStatementModelUsage;
These flags specify how the GdaDataModel returned when executing a GdaStatement will be used
access to the data model will be random (usually this will result in a data model completely stored in memory) | |
access to the data model will be done using a cursor moving forward | |
access to the data model will be done using a cursor moving backward | |
access to the data model will be done using a cursor (moving both forward and backward) | |
specifies that the data model should be executed even if some parameters required to execute it are invalid (in this case the data model will have no row, and will automatically be re-run when the missing parameters are once again valid) |
typedef enum { GDA_STATEMENT_PARSE_ERROR, GDA_STATEMENT_SYNTAX_ERROR, GDA_STATEMENT_NO_CNC_ERROR, GDA_STATEMENT_CNC_CLOSED_ERROR, GDA_STATEMENT_EXEC_ERROR, GDA_STATEMENT_PARAM_TYPE_ERROR, GDA_STATEMENT_PARAM_ERROR } GdaStatementError;
GdaStatement * gda_statement_new (void
);
Creates a new GdaStatement object
Returns : |
the new object |
GdaStatement * gda_statement_copy (GdaStatement *orig
);
Copy constructor
|
a GdaStatement to make a copy of |
Returns : |
a the new copy of orig . [transfer full]
|
gchar * gda_statement_serialize (GdaStatement *stmt
);
Creates a string representing the contents of stmt
.
|
a GdaStatement object |
Returns : |
a string containing the serialized version of stmt
|
gboolean gda_statement_get_parameters (GdaStatement *stmt
,GdaSet **out_params
,GError **error
);
Get a new GdaSet object which groups all the execution parameters
which stmt
needs. This new object is returned though out_params
.
Note that if stmt
does not need any parameter, then out_params
is set to NULL
.
|
a GdaStatement object |
|
a place to store a new GdaSet object, or NULL . [out][allow-none][transfer full]
|
|
a place to store errors, or NULL
|
Returns : |
TRUE if no error occurred. |
#define gda_statement_to_sql(stmt,params,error) gda_statement_to_sql_extended ((stmt), NULL, (params), GDA_STATEMENT_SQL_PARAMS_SHORT, NULL, (error))
gchar * gda_statement_to_sql_extended (GdaStatement *stmt
,GdaConnection *cnc
,GdaSet *params
,GdaStatementSqlFlag flags
,GSList **params_used
,GError **error
);
Renders stmt
as an SQL statement, with some control on how it is rendered.
If cnc
is not NULL
, then the rendered SQL will better be suited to be used by cnc
(in particular
it may include some SQL tweaks and/or proprietary extensions specific to the database engine used by cnc
):
in this case the result is similar to calling gda_connection_statement_to_sql()
.
|
a GdaStatement object |
|
a GdaConnection object, or NULL . [allow-none]
|
|
parameters contained in a single GdaSet object, or NULL . [allow-none]
|
|
a set of flags to control the rendering |
|
a place to store the list of actual GdaHolder objects in params used to do the rendering, or NULL . [element-type GdaHolder][out][transfer container][allow-none]
|
|
a place to store errors, or NULL
|
Returns : |
a new string if no error occurred. [transfer full] |
GdaSqlStatementType gda_statement_get_statement_type (GdaStatement *stmt
);
Get the type of statement held by stmt
. It returns GDA_SQL_STATEMENT_NONE if
stmt
does not hold any statement
|
a GdaStatement object |
Returns : |
the statement type. [transfer none] |
gboolean gda_statement_is_useless (GdaStatement *stmt
);
Tells if stmt
is composed only of spaces (that is it has no real SQL code), and is completely
useless as such.
|
a GdaStatement object |
Returns : |
TRUE if executing stmt does nothing |
gboolean gda_statement_check_structure (GdaStatement *stmt
,GError **error
);
Checks that stmt
's structure is correct.
|
a GdaStatement object |
|
a place to store errors, or NULL
|
Returns : |
TRUE if stmt 's structure is correct |
gboolean gda_statement_check_validity (GdaStatement *stmt
,GdaConnection *cnc
,GError **error
);
If cnc
is not NULL
then checks that every object (table, field, function) used in stmt
actually exists in cnc
's database
If cnc
is NULL
, then cleans anything related to cnc
in stmt
.
See gda_sql_statement_check_validity()
for more information.
|
a GdaStatement object |
|
a GdaConnection object, or NULL . [allow-none]
|
|
a place to store errors, or NULL
|
Returns : |
TRUE if every object actually exists in cnc 's database |
gboolean gda_statement_normalize (GdaStatement *stmt
,GdaConnection *cnc
,GError **error
);
"Normalizes" some parts of stmt
, see gda_sql_statement_normalize()
for more
information.
|
a GdaStatement object |
|
a GdaConnection object |
|
a place to store errors, or NULL
|
Returns : |
TRUE if no error occurred |
"structure"
property "structure" gpointer : Read / Write
This property changes or queries the internal GdaSqlStatement structure. A copy is made when either setting or getting that property.
"checked"
signalvoid user_function (GdaStatement *stmt,
GdaConnection *arg1,
gboolean arg2,
gpointer user_data) : Run First
Gets emitted whenever the structure and contents
of stmt
have been verified (emitted after gda_statement_check_validity()
).
|
the GdaStatement object |
|
user data set when the signal handler was connected. |
"reset"
signalvoid user_function (GdaStatement *stmt,
gpointer user_data) : Run First
Gets emitted whenever the stmt
has changed
This signal is emitted whenever the internal GdaSqlStatement structure has changed
|
the GdaStatement object |
|
user data set when the signal handler was connected. |