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GNOME Data Access 3.0 manual | ![]() |
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GdaServerProvider; GdaServerProviderInfo; const gchar* gda_server_provider_get_version (GdaServerProvider *provider); GdaServerProviderInfo* gda_server_provider_get_info (GdaServerProvider *provider, GdaConnection *cnc); gboolean gda_server_provider_open_connection (GdaServerProvider *provider, GdaConnection *cnc, GdaQuarkList *params, const gchar *username, const gchar *password); gboolean gda_server_provider_close_connection (GdaServerProvider *provider, GdaConnection *cnc); const gchar* gda_server_provider_get_server_version (GdaServerProvider *provider, GdaConnection *cnc); const gchar* gda_server_provider_get_database (GdaServerProvider *provider, GdaConnection *cnc); gboolean gda_server_provider_change_database (GdaServerProvider *provider, GdaConnection *cnc, const gchar *name); gboolean gda_server_provider_supports_operation (GdaServerProvider *provider, GdaConnection *cnc, GdaServerOperationType type, GdaParameterList *options); GdaServerOperation* gda_server_provider_create_operation (GdaServerProvider *provider, GdaConnection *cnc, GdaServerOperationType type, GdaParameterList *options, GError **error); gchar* gda_server_provider_render_operation (GdaServerProvider *provider, GdaConnection *cnc, GdaServerOperation *op, GError **error); gboolean gda_server_provider_perform_operation (GdaServerProvider *provider, GdaConnection *cnc, GdaServerOperation *op, GError **error); GList* gda_server_provider_execute_command (GdaServerProvider *provider, GdaConnection *cnc, GdaCommand *cmd, GdaParameterList *params); GdaObject* gda_server_provider_execute_query (GdaServerProvider *provider, GdaConnection *cnc, GdaQuery *query, GdaParameterList *params); gchar* gda_server_provider_get_last_insert_id (GdaServerProvider *provider, GdaConnection *cnc, GdaDataModel *recset); gboolean gda_server_provider_begin_transaction (GdaServerProvider *provider, GdaConnection *cnc, const gchar *name, GdaTransactionIsolation level, GError **error); gboolean gda_server_provider_commit_transaction (GdaServerProvider *provider, GdaConnection *cnc, const gchar *name, GError **error); gboolean gda_server_provider_rollback_transaction (GdaServerProvider *provider, GdaConnection *cnc, const gchar *name, GError **error); gboolean gda_server_provider_add_savepoint (GdaServerProvider *provider, GdaConnection *cnc, const gchar *name, GError **error); gboolean gda_server_provider_rollback_savepoint (GdaServerProvider *provider, GdaConnection *cnc, const gchar *name, GError **error); gboolean gda_server_provider_delete_savepoint (GdaServerProvider *provider, GdaConnection *cnc, const gchar *name, GError **error); gboolean gda_server_provider_supports_feature (GdaServerProvider *provider, GdaConnection *cnc, GdaConnectionFeature feature); GdaDataModel* gda_server_provider_get_schema (GdaServerProvider *provider, GdaConnection *cnc, GdaConnectionSchema schema, GdaParameterList *params, GError **error); GdaDataHandler* gda_server_provider_get_data_handler_gtype (GdaServerProvider *provider, GdaConnection *cnc, GType for_type); GdaDataHandler* gda_server_provider_get_data_handler_dbms (GdaServerProvider *provider, GdaConnection *cnc, const gchar *for_type); GValue* gda_server_provider_string_to_value (GdaServerProvider *provider, GdaConnection *cnc, const gchar *string, GType prefered_type, gchar **dbms_type); gchar* gda_server_provider_value_to_sql_string (GdaServerProvider *provider, GdaConnection *cnc, GValue *from); const gchar* gda_server_provider_get_default_dbms_type (GdaServerProvider *provider, GdaConnection *cnc, GType type); gchar* gda_server_provider_escape_string (GdaServerProvider *provider, GdaConnection *cnc, const gchar *str); gchar* gda_server_provider_unescape_string (GdaServerProvider *provider, GdaConnection *cnc, const gchar *str);
The GdaServerProvider class is a virtual class which all the DBMS providers must inherit, and implement its virtual mathods.
typedef struct { gchar *provider_name; /* equal to the return of gda_connection_get_provider() */ /* * TRUE if all comparisons of names can be done on the lower case versions of the objects names */ gboolean is_case_insensitive; /* * TRUE to suppose that there are implicit casts available for data types which have * the same gda type */ gboolean implicit_data_types_casts; /* * TRUE if writing "... FROM mytable AS alias..." is ok, and FALSE if we need to write this as * "... FROM mytable alias..." */ gboolean alias_needs_as_keyword; /* TRUE is tables can be aliased in SELECT queries*/ gboolean supports_alias; /* TRUE if it is possible to write "SELECT table.field ..." or if it is only possible * to write "SELECT field..." */ gboolean supports_prefixed_fields; /* TRUE if non lower case identifiers must be surrounded by double quotes to distinguish them * with their lower case equivalent, that is TRUE if by default the non lower case identifiers * are converted into lower case. */ gboolean quote_non_lc_identifiers; /* reserved for extensions */ gboolean reserved[20]; } GdaServerProviderInfo;
const gchar* gda_server_provider_get_version (GdaServerProvider *provider);
Get the version of the given provider.
provider : |
a GdaServerProvider object. |
Returns : | a string containing the version identification. |
GdaServerProviderInfo* gda_server_provider_get_info (GdaServerProvider *provider, GdaConnection *cnc);
Retreive some information specific to the provider. The returned GdaServerProviderInfo structure must not be modified
provider : |
a GdaServerProvider object. |
cnc : |
a GdaConnection, or NULL
|
Returns : | a GdaServerProviderInfo pointer or NULL if an error occurred
|
gboolean gda_server_provider_open_connection (GdaServerProvider *provider, GdaConnection *cnc, GdaQuarkList *params, const gchar *username, const gchar *password);
Tries to open a new connection on the given GdaServerProvider object.
provider : |
a GdaServerProvider object. |
cnc : |
a GdaConnection object. |
params : |
|
username : |
user name for logging in. |
password : |
password for authentication. |
Returns : | TRUE if no error occurred |
gboolean gda_server_provider_close_connection (GdaServerProvider *provider, GdaConnection *cnc);
provider : |
|
cnc : |
|
Returns : |
const gchar* gda_server_provider_get_server_version (GdaServerProvider *provider, GdaConnection *cnc);
provider : |
|
cnc : |
|
Returns : |
const gchar* gda_server_provider_get_database (GdaServerProvider *provider, GdaConnection *cnc);
Proxy the call to the get_database method on the GdaServerProvider class to the corresponding provider.
provider : |
a GdaServerProvider object. |
cnc : |
a GdaConnection object. |
Returns : | the name of the current database. |
gboolean gda_server_provider_change_database (GdaServerProvider *provider, GdaConnection *cnc, const gchar *name);
Proxy the call to the change_database method on the " GdaServerProvider class to the corresponding provider.
provider : |
a GdaServerProvider object. |
cnc : |
a GdaConnection object. |
name : |
database name. |
Returns : | TRUE if successful, FALSE otherwise.
|
gboolean gda_server_provider_supports_operation (GdaServerProvider *provider, GdaConnection *cnc, GdaServerOperationType type, GdaParameterList *options);
Tells if provider
supports the type
of operation on the cnc
connection, using the
(optional) options
parameters.
provider : |
a GdaServerProvider object |
cnc : |
a GdaConnection object which would be used to perform an action |
type : |
the type of operation requested |
options : |
a list of named parameters, or NULL
|
Returns : | TRUE if the operation is supported |
GdaServerOperation* gda_server_provider_create_operation (GdaServerProvider *provider, GdaConnection *cnc, GdaServerOperationType type, GdaParameterList *options, GError **error);
Creates a new GdaServerOperation object which can be modified in order to perform the type
type of
action. The options
can contain:
provider : |
a GdaServerProvider object |
cnc : |
a GdaConnection object which will be used to perform an action |
type : |
the type of operation requested |
options : |
an optional list of parameters |
error : |
a place to store an error, or NULL
|
Returns : | a new GdaServerOperation object, or NULL in the provider does not support the type type
of operation or if an error occurred
|
gchar* gda_server_provider_render_operation (GdaServerProvider *provider, GdaConnection *cnc, GdaServerOperation *op, GError **error);
Creates an SQL statement (possibly using some specific extensions of the DBMS) corresponding to the
op
operation.
provider : |
a GdaServerProvider object |
cnc : |
a GdaConnection object which will be used to perform an action |
op : |
a GdaServerOperation object |
error : |
a place to store an error, or NULL
|
Returns : | a new string, or NULL if an error occurred or operation cannot be rendered as SQL.
|
gboolean gda_server_provider_perform_operation (GdaServerProvider *provider, GdaConnection *cnc, GdaServerOperation *op, GError **error);
Performs the operation described by op
.
provider : |
a GdaServerProvider object |
cnc : |
a GdaConnection object which will be used to perform an action |
op : |
a GdaServerOperation object |
error : |
a place to store an error, or NULL
|
Returns : | TRUE if no error occurred |
GList* gda_server_provider_execute_command (GdaServerProvider *provider, GdaConnection *cnc, GdaCommand *cmd, GdaParameterList *params);
Executes one or more SQL statements stored in command
, and returns a list of
GdaDataModel and/or GdaParameterList (or NULL
) objects for each SQL statement
in command
following the rule (the number and order of items contained in the returned list is the
same as the number and order of SQL queries in command
if there is no error,
otherwise it depends on the execution options in params
):
A GdaDataModel is in the list if the statement was a SELECT statement and the statement was successufully executed
A GdaParameterList is in the list if the statement was not a SELECT statement and the statement was successufully executed. In this case (if the provider supports it), then the GdaParameterList may contain:
a (gint) GdaParameter named "IMPACTED_ROWS"
a (GObject) GdaParameter named "EVENT" which contains a GdaConnectionEvent
NULL
is in the list if the correcponding statement could not be executed
See the documentation of the gda_connection_execute_command()
for information
about the params
list of parameters.
For every executed statement, a GdaDataModel, a GdaParameterList or NULL
will be appended to the returned list.
The returned list may contain fewer items than the cmd
command contained statements depending on the
options of command
(see gda_command_set_options()
).
provider : |
a GdaServerProvider object |
cnc : |
a GdaConnection object using |
cmd : |
a GdaCommand |
params : |
a GdaParameterList containing a list of optional parameters |
Returns : | a new list, or NULL
|
GdaObject* gda_server_provider_execute_query (GdaServerProvider *provider, GdaConnection *cnc, GdaQuery *query, GdaParameterList *params);
Executes the query
query, and returns:
A GdaDataModel if the query was a SELECT statement and the statement was successufully executed
A GdaParameterList if the query was not a SELECT query and the query was successufully executed. In this case (if the provider supports it), then the GdaParameterList may contain:
a (gint) GdaParameter named "IMPACTED_ROWS"
a (GObject) GdaParameter named "EVENT" which contains a GdaConnectionEvent
NULL
is in the list if the query could not be executed
The differences between this function and gda_server_provider_execute_command()
are:
Only one query can be executed at a time
If the database provider supports it, prepared statements can be used
Blobs are handled correctly (because blobs are usually not handled using SQL)
provider : |
a GdaServerProvider object |
cnc : |
a GdaConnection object using |
query : |
a GdaQuery |
params : |
a GdaParameterList object obtained using gda_query_get_parameter_list(query )
|
Returns : | a new (GdaDataModel or GdaParameterList) object, or NULL
|
gchar* gda_server_provider_get_last_insert_id (GdaServerProvider *provider, GdaConnection *cnc, GdaDataModel *recset);
Retrieve from the given GdaServerProvider the ID of the last inserted row. A connection must be specified, and, optionally, a result set. If not NULL, the provider should try to get the last insert ID for the given result set.
Beware however that the interpretation and usage of this value depends on the DBMS type being used, see the limitations of each DBMS for more information.
provider : |
a GdaServerProvider object. |
cnc : |
connection to act upon. |
recset : |
resultset to get the last insert ID from. |
Returns : | a string representing the ID of the last inserted row, or NULL if an error occurred or no row has been inserted. It is the caller's reponsibility to free the returned string. |
gboolean gda_server_provider_begin_transaction (GdaServerProvider *provider, GdaConnection *cnc, const gchar *name, GdaTransactionIsolation level, GError **error);
provider : |
|
cnc : |
|
name : |
the name of the transation to start |
level : |
|
error : |
a place to store errors, or NULL
|
Returns : |
gboolean gda_server_provider_commit_transaction (GdaServerProvider *provider, GdaConnection *cnc, const gchar *name, GError **error);
provider : |
|
cnc : |
|
name : |
the name of the transation to commit |
error : |
a place to store errors, or NULL
|
Returns : |
gboolean gda_server_provider_rollback_transaction (GdaServerProvider *provider, GdaConnection *cnc, const gchar *name, GError **error);
provider : |
|
cnc : |
|
name : |
the name of the transation to commit |
error : |
a place to store errors, or NULL
|
Returns : |
gboolean gda_server_provider_add_savepoint (GdaServerProvider *provider, GdaConnection *cnc, const gchar *name, GError **error);
provider : |
a GdaServerProvider object |
cnc : |
a GdaConnection object |
name : |
name of the savepoint to add |
error : |
a place to store errors or NULL
|
Returns : | TRUE if no error occurred |
gboolean gda_server_provider_rollback_savepoint (GdaServerProvider *provider, GdaConnection *cnc, const gchar *name, GError **error);
provider : |
a GdaServerProvider object |
cnc : |
a GdaConnection object |
name : |
name of the savepoint to rollback to |
error : |
a place to store errors or NULL
|
Returns : | TRUE if no error occurred |
gboolean gda_server_provider_delete_savepoint (GdaServerProvider *provider, GdaConnection *cnc, const gchar *name, GError **error);
provider : |
a GdaServerProvider object |
cnc : |
a GdaConnection object |
name : |
name of the savepoint to delete |
error : |
a place to store errors or NULL
|
Returns : | TRUE if no error occurred |
gboolean gda_server_provider_supports_feature (GdaServerProvider *provider, GdaConnection *cnc, GdaConnectionFeature feature);
provider : |
|
cnc : |
|
feature : |
|
Returns : |
GdaDataModel* gda_server_provider_get_schema (GdaServerProvider *provider, GdaConnection *cnc, GdaConnectionSchema schema, GdaParameterList *params, GError **error);
Get a GdaDataModel containing the requested information. See this section for more
information on the columns of the returned GdaDataModel depending on requested schema
, and for the possible
parameters of params
, see the
get_schema()
virtual method for providers for more details.
provider : |
a GdaServerProvider object |
cnc : |
a GdaConnection object, or NULL
|
schema : |
the requested kind of information |
params : |
optional parameters |
error : |
|
Returns : | a new GdaDataModel, or NULL if an error occurred.
|
GdaDataHandler* gda_server_provider_get_data_handler_gtype (GdaServerProvider *provider, GdaConnection *cnc, GType for_type);
Find a GdaDataHandler object to manipulate data of type for_type
.
provider : |
a server provider. |
cnc : |
a GdaConnection object, or NULL
|
for_type : |
a GType |
Returns : | a GdaDataHandler, or NULL if the provider does not support the requested for_type data type
|
GdaDataHandler* gda_server_provider_get_data_handler_dbms (GdaServerProvider *provider, GdaConnection *cnc, const gchar *for_type);
Find a GdaDataHandler object to manipulate data of type for_type
.
provider : |
a server provider. |
cnc : |
a GdaConnection object, or NULL
|
for_type : |
a DBMS type definition |
Returns : | a GdaDataHandler, or NULL if the provider does not know about the for_type type
|
GValue* gda_server_provider_string_to_value (GdaServerProvider *provider, GdaConnection *cnc, const gchar *string, GType prefered_type, gchar **dbms_type);
Use provider
to create a new GValue from a single string representation.
The prefered_type
can optionnaly ask provider
to return a GValue of the requested type
(but if such a value can't be created from string
, then NULL
is returned);
pass G_TYPE_INVALID if any returned type is acceptable.
The returned value is either a new GValue or NULL
in the following cases:
- string
cannot be converted to prefered_type
type
- the provider does not handle prefered_type
- the provider could not make a GValue from string
provider : |
a server provider. |
cnc : |
a GdaConnection object. |
string : |
the SQL string to convert to a value |
prefered_type : |
a GType |
dbms_type : |
|
Returns : | a new GValue, or NULL
|
gchar* gda_server_provider_value_to_sql_string (GdaServerProvider *provider, GdaConnection *cnc, GValue *from);
Produces a fully quoted and escaped string from a GValue
provider : |
a server provider. |
cnc : |
a GdaConnection object, or NULL
|
from : |
GValue to convert from |
Returns : | escaped and quoted value or NULL if not supported. |
const gchar* gda_server_provider_get_default_dbms_type (GdaServerProvider *provider, GdaConnection *cnc, GType type);
Get the name of the most common data type which has type
type.
The returned value may be NULL
either if the provider does not implement that method, or if
there is no DBMS data type which could contain data of the g_type
type (for example NULL
may be
returned if a DBMS has integers only up to 4 bytes and a G_TYPE_INT64 is requested).
provider : |
a server provider. |
cnc : |
a GdaConnection object or NULL
|
type : |
a GType value type |
Returns : | the name of the DBMS type, or NULL
|
gchar* gda_server_provider_escape_string (GdaServerProvider *provider, GdaConnection *cnc, const gchar *str);
Escapes str
for use within an SQL command (to avoid SQL injection attacks). Note that the returned value still needs
to be enclosed in single quotes before being used in an SQL statement.
provider : |
a server provider. |
cnc : |
a GdaConnection object, or NULL
|
str : |
a string to escape |
Returns : | a new string suitable to use in SQL statements |
gchar* gda_server_provider_unescape_string (GdaServerProvider *provider, GdaConnection *cnc, const gchar *str);
Unescapes str
for use within an SQL command. This is the exact opposite of gda_server_provider_escape_string()
.
provider : |
a server provider. |
cnc : |
a GdaConnection object, or NULL
|
str : |
a string to escape |
Returns : | a new string |