| Top | |
|
|
|
| GdaStatement | |
| enum | GdaStatementSqlFlag |
| enum | GdaStatementModelUsage |
| enum | GdaStatementError |
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.
gchar *
gda_statement_serialize (GdaStatement *stmt);
Creates a string representing the contents 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.
stmt |
a GdaStatement object |
|
out_params |
[out][allow-none][transfer full] | |
error |
a place to store errors, or |
#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().
stmt |
a GdaStatement object |
|
cnc |
a GdaConnection object, or |
[allow-none] |
params |
[allow-none] | |
flags |
a set of flags to control the rendering |
|
params_used |
a place to store the list of actual GdaHolder objects in |
[element-type GdaHolder][out][transfer container][allow-none] |
error |
a place to store errors, or |
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
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.
gboolean gda_statement_check_structure (GdaStatement *stmt,GError **error);
Checks that 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.
stmt |
a GdaStatement object |
|
cnc |
a GdaConnection object, or |
[allow-none] |
error |
a place to store errors, or |
gboolean gda_statement_normalize (GdaStatement *stmt,GdaConnection *cnc,GError **error);
"Normalizes" some parts of stmt
, see gda_sql_statement_normalize() for more
information.
stmt |
a GdaStatement object |
|
cnc |
a GdaConnection object |
|
error |
a place to store errors, or |
Specifies rendering options
|
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 |
||
|
time and timestamp with a timezone information are converted to GMT before rendering, and rendering does not show the timezone information |
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) |
||
|
specifies that the data model's contents will be fully loaded into the client side (the memory of the process using Libgda), not requiring the server any more to access the data (the default behaviour is to access the server any time data is to be read, and data is cached in memory). This flag is useful only if used in conjunction with the GDA_STATEMENT_MODEL_RANDOM_ACCESS flag (otherwise an error will be returned). |
“checked” signalvoid user_function (GdaStatement *gdastatement, GdaConnection *arg1, gboolean arg2, gpointer user_data)
Gets emitted whenever the structure and contents
of the statement have been verified (emitted after gda_statement_check_validity()).
Flags: Run First
“reset” signalvoid user_function (GdaStatement *gdastatement, gpointer user_data)
Gets emitted whenever the statement has changed
Flags: Run First