GdaServerProvider

GdaServerProvider — Base class for all the DBMS providers

Synopsis

                    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);

Object Hierarchy

  GObject
   +----GdaServerProvider
         +----GdaSqliteProvider

Description

The GdaServerProvider class is a virtual class which all the DBMS providers must inherit, and implement its virtual mathods.

Details

GdaServerProvider

typedef struct _GdaServerProvider GdaServerProvider;


GdaServerProviderInfo

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;


gda_server_provider_get_version ()

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.

gda_server_provider_get_info ()

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

gda_server_provider_open_connection ()

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.

username :

user name for logging in.

password :

password for authentication.

Returns :

TRUE if no error occurred

gda_server_provider_close_connection ()

gboolean            gda_server_provider_close_connection
                                                        (GdaServerProvider *provider,
                                                         GdaConnection *cnc);

gda_server_provider_get_server_version ()

const gchar *       gda_server_provider_get_server_version
                                                        (GdaServerProvider *provider,
                                                         GdaConnection *cnc);

gda_server_provider_get_database ()

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.

gda_server_provider_change_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.

gda_server_provider_supports_operation ()

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

gda_server_provider_create_operation ()

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:

  • parameters which ID is a path in the resulting GdaServerOperation object, to initialize some value
  • parameters which may change the contents of the GdaServerOperation, see this section for more information

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

gda_server_provider_render_operation ()

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.

gda_server_provider_perform_operation ()

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

gda_server_provider_execute_command ()

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

gda_server_provider_execute_query ()

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

gda_server_provider_get_last_insert_id ()

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.

gda_server_provider_begin_transaction ()

gboolean            gda_server_provider_begin_transaction
                                                        (GdaServerProvider *provider,
                                                         GdaConnection *cnc,
                                                         const gchar *name,
                                                         GdaTransactionIsolation level,
                                                         GError **error);

name :

the name of the transation to start

error :

a place to store errors, or NULL

gda_server_provider_commit_transaction ()

gboolean            gda_server_provider_commit_transaction
                                                        (GdaServerProvider *provider,
                                                         GdaConnection *cnc,
                                                         const gchar *name,
                                                         GError **error);

name :

the name of the transation to commit

error :

a place to store errors, or NULL

gda_server_provider_rollback_transaction ()

gboolean            gda_server_provider_rollback_transaction
                                                        (GdaServerProvider *provider,
                                                         GdaConnection *cnc,
                                                         const gchar *name,
                                                         GError **error);

name :

the name of the transation to commit

error :

a place to store errors, or NULL

gda_server_provider_add_savepoint ()

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

gda_server_provider_rollback_savepoint ()

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

gda_server_provider_delete_savepoint ()

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

gda_server_provider_supports_feature ()

gboolean            gda_server_provider_supports_feature
                                                        (GdaServerProvider *provider,
                                                         GdaConnection *cnc,
                                                         GdaConnectionFeature feature);

gda_server_provider_get_schema ()

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

Returns :

a new GdaDataModel, or NULL if an error occurred.

gda_server_provider_get_data_handler_gtype ()

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

gda_server_provider_get_data_handler_dbms ()

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

gda_server_provider_string_to_value ()

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

Returns :

a new GValue, or NULL

gda_server_provider_value_to_sql_string ()

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.

gda_server_provider_get_default_dbms_type ()

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

gda_server_provider_escape_string ()

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

gda_server_provider_unescape_string ()

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