GdaClient

GdaClient — Database client access

Functions

Signals

void event-notification Run Last

Types and Values

Object Hierarchy

    GObject
    ╰── GdaClient

Description

This class is the main entry point for libgda client applications. It provides the way by which client applications open connections. Thus, before using any other database-oriented function in libgda, applications must create a GdaClient object (via gda_client_new), and, once created, open the connections from it.

GdaClient also provides a way to treat several connections as if they were only one (a connection pool), which allows applications to, for instance, commit/rollback a transaction in all the connections being managed by a unique GdaClient object, or obtain the list of all tables in all opened connections.

Database creation and destruction is done through a GdaClient object uding the gda_client_create_database() and gda_client_drop_database() methods. Note however that depending on the provider, an opened connection may be required in order to create or destroy a database.

Functions

gda_client_new ()

GdaClient *
gda_client_new (void);

Creates a new GdaClient object, which is the entry point for libgda client applications. This object, once created, can be used for opening new database connections and activating other services available to GDA clients.

Returns

the newly created object.


gda_client_declare_connection ()

void
gda_client_declare_connection (GdaClient *client,
                               GdaConnection *cnc);

Declares the cnc to client . This function should not be used directly

Parameters

client

a GdaClient object

 

cnc

a GdaConnection object

 

gda_client_open_connection ()

GdaConnection *
gda_client_open_connection (GdaClient *client,
                            const gchar *dsn,
                            const gchar *username,
                            const gchar *password,
                            GdaConnectionOptions options,
                            GError **error);

This function is the way of opening database connections with libgda.

Establishes a connection to a data source. The connection will be opened if no identical connection is available in the GdaClient connection pool, and re-used if available. If you dont want to share the connection, specify GDA_CONNECTION_OPTIONS_DONT_SHARE as one of the flags in the options parameter.

The username and password used to actually open the connection are the first non-NULL string being chosen by order from

  • the username or password
  • the username or password sprcified in the DSN definition
  • the USERNAME= and PASSWORD= parts of the connection string in the DSN definition

If a new GdaConnection is created, then the caller will hold a reference on it, and if a GdaConnection already existing is used, then the reference count of that object will be increased by one.

Parameters

client

a GdaClient object.

 

dsn

data source name.

 

username

user name or NULL

 

password

password for username , or NULL

 

options

options for the connection (see GdaConnectionOptions).

 

error

a place to store an error, or NULL

 

Returns

the opened connection if successful, NULL if there was an error.


gda_client_open_connection_from_string ()

GdaConnection *
gda_client_open_connection_from_string
                               (GdaClient *client,
                                const gchar *provider_id,
                                const gchar *cnc_string,
                                const gchar *username,
                                const gchar *password,
                                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 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. Do not add extra whitespace after the semicolumn separator. The possible keys depend on the provider, but these keys should work with all providers: USER, PASSWORD, HOST, DATABASE, PORT

The username and password used to actually open the connection are the first non-NULL string being chosen by order from

  • the username or password
  • the USERNAME= and PASSWORD= parts of the cnc_string

Parameters

client

a GdaClient object.

 

provider_id

provider ID to connect to.

 

cnc_string

connection string.

 

username

user name.

 

password

password for username .

 

options

options for the connection (see GdaConnectionOptions).

 

error

a place to store an error, or NULL

 

Returns

the opened connection if successful, NULL if there is an error.


gda_client_get_connections ()

const GList *
gda_client_get_connections (GdaClient *client);

Gets the list of all open connections in the given GdaClient object. The GList returned is an internal pointer, so DON'T TRY TO FREE IT.

Parameters

client

a GdaClient object.

 

Returns

a GList of GdaConnection objects; dont't modify that list


gda_client_find_connection ()

GdaConnection *
gda_client_find_connection (GdaClient *client,
                            const gchar *dsn,
                            const gchar *username,
                            const gchar *password);

Looks for an open connection given a data source name (per libgda configuration), a username and a password.

This function iterates over the list of open connections in the given GdaClient and looks for one that matches the given data source name, username and password.

Parameters

client

a GdaClient object.

 

dsn

data source name.

 

username

user name.

 

password

password for username .

 

Returns

a pointer to the found connection, or NULL if it could not be found.


gda_client_close_all_connections ()

void
gda_client_close_all_connections (GdaClient *client);

Closes all connections opened by the given GdaClient object.

Parameters

client

a GdaClient object.

 

gda_client_notify_event ()

void
gda_client_notify_event (GdaClient *client,
                         GdaConnection *cnc,
                         GdaClientEvent event,
                         GdaParameterList *params);

Notifies an event to the given GdaClient's listeners. The event can be anything (see GdaClientEvent) ranging from a connection opening operation, to changes made to a table in an underlying database.

Parameters

client

a GdaClient object.

 

cnc

a GdaConnection object where the event has occurred.

 

event

event ID.

 

params

parameters associated with the event.

 

gda_client_notify_error_event ()

void
gda_client_notify_error_event (GdaClient *client,
                               GdaConnection *cnc,
                               GdaConnectionEvent *error);

Notifies the given GdaClient of the GDA_CLIENT_EVENT_ERROR event.

Parameters

client

a GdaClient object.

 

cnc

a GdaConnection object.

 

error

the error to be notified.

 

gda_client_notify_connection_opened_event ()

void
gda_client_notify_connection_opened_event
                               (GdaClient *client,
                                GdaConnection *cnc);

Notifies the given GdaClient of the GDA_CLIENT_EVENT_CONNECTION_OPENED event.

Parameters

client

a GdaClient object.

 

cnc

a GdaConnection object.

 

gda_client_notify_connection_closed_event ()

void
gda_client_notify_connection_closed_event
                               (GdaClient *client,
                                GdaConnection *cnc);

Notifies the given GdaClient of the GDA_CLIENT_EVENT_CONNECTION_CLOSED event.

Parameters

client

a GdaClient object.

 

cnc

a GdaConnection object.

 

gda_client_begin_transaction ()

gboolean
gda_client_begin_transaction (GdaClient *client,
                              const gchar *name,
                              GdaTransactionIsolation level,
                              GError **error);

Starts a transaction on all connections being managed by the given GdaClient. It is important to note that this operates on all connections opened within a GdaClient, which could not be what you're looking for.

To execute a transaction on a unique connection, use gda_connection_begin_transaction, gda_connection_commit_transaction and gda_connection_rollback_transaction.

Parameters

client

a GdaClient object.

 

name

the name of the transation to start

 

error

a place to store errors, or NULL

 

Returns

TRUE if all transactions could be started successfully, or FALSE if one of them fails.


gda_client_commit_transaction ()

gboolean
gda_client_commit_transaction (GdaClient *client,
                               const gchar *name,
                               GError **error);

Commits a running transaction on all connections being managed by the given GdaClient. It is important to note that this operates on all connections opened within a GdaClient, which could not be what you're looking for.

To execute a transaction on a unique connection, use gda_connection_begin_transaction, gda_connection_commit_transaction and gda_connection_rollback_transaction.

Parameters

client

a GdaClient object.

 

name

the name of the transation to commit

 

error

a place to store errors, or NULL

 

Returns

TRUE if all transactions could be committed successfully, or FALSE if one of them fails.


gda_client_rollback_transaction ()

gboolean
gda_client_rollback_transaction (GdaClient *client,
                                 const gchar *name,
                                 GError **error);

Cancels a running transaction on all connections being managed by the given GdaClient. It is important to note that this operates on all connections opened within a GdaClient, which could not be what you're looking for.

To execute a transaction on a unique connection, use gda_connection_begin_transaction, gda_connection_commit_transaction and gda_connection_rollback_transaction.

Parameters

client

a GdaClient object.

 

name

the name of the transation to rollback

 

error

a place to store errors, or NULL

 

Returns

TRUE if all transactions could be cancelled successfully, or FALSE if one of them fails.


gda_client_get_dsn_specs ()

gchar *
gda_client_get_dsn_specs (GdaClient *client,
                          const gchar *provider);

Get an XML string representing the parameters which can be present in the DSN string used to open a connection.

Parameters

client

a GdaClient object.

 

provider

a provider

 

Returns

a string (free it after usage), or NULL if an error occurred


gda_client_prepare_create_database ()

GdaServerOperation *
gda_client_prepare_create_database (GdaClient *client,
                                    const gchar *db_name,
                                    const gchar *provider);

Creates a new GdaServerOperation object which contains the specifications required to create a database. Once these specifications provided, use gda_client_perform_create_database() to perform the database creation.

If db_name is left NULL, then the name of the database to create will have to be set in the returned GdaServerOperation using gda_server_operation_set_value_at().

Parameters

client

a GdaClient object.

 

db_name

the name of the database to create, or NULL

 

provider

a provider

 

Returns

new GdaServerOperation object, or NULL if the provider does not support database creation


gda_client_perform_create_database ()

gboolean
gda_client_perform_create_database (GdaClient *client,
                                    GdaServerOperation *op,
                                    GError **error);

Creates a new database using the specifications in op , which must have been obtained using gda_client_prepare_create_database()

Parameters

client

a GdaClient object.

 

op

a GdaServerOperation object obtained using gda_client_prepare_create_database()

 

error

a place to store en error, or NULL

 

Returns

TRUE if no error occurred and the database has been created


gda_client_prepare_drop_database ()

GdaServerOperation *
gda_client_prepare_drop_database (GdaClient *client,
                                  const gchar *db_name,
                                  const gchar *provider);

Creates a new GdaServerOperation object which contains the specifications required to drop a database. Once these specifications provided, use gda_client_perform_drop_database() to perform the database creation.

If db_name is left NULL, then the name of the database to drop will have to be set in the returned GdaServerOperation using gda_server_operation_set_value_at().

Parameters

client

a GdaClient object.

 

db_name

the name of the database to drop, or NULL

 

provider

a provider

 

Returns

new GdaServerOperation object, or NULL if the provider does not support database destruction


gda_client_perform_drop_database ()

gboolean
gda_client_perform_drop_database (GdaClient *client,
                                  GdaServerOperation *op,
                                  GError **error);

Destroys an existing database using the specifications in op , which must have been obtained using gda_client_prepare_drop_database()

Parameters

client

a GdaClient object.

 

op

a GdaServerOperation object obtained using gda_client_prepare_drop_database()

 

error

a place to store en error, or NULL

 

Returns

TRUE if no error occurred and the database has been destroyed

Types and Values

GdaClient

typedef struct _GdaClient GdaClient;


enum GdaClientEvent

Members

GDA_CLIENT_EVENT_INVALID

   

GDA_CLIENT_EVENT_ERROR

   

GDA_CLIENT_EVENT_CONNECTION_OPENED

   

GDA_CLIENT_EVENT_CONNECTION_CLOSED

   

GDA_CLIENT_EVENT_TRANSACTION_STARTED

   

GDA_CLIENT_EVENT_TRANSACTION_COMMITTED

   

GDA_CLIENT_EVENT_TRANSACTION_CANCELLED

   

Signal Details

The “event-notification” signal

void
user_function (GdaClient        *gdaclient,
               GdaConnection    *arg1,
               GdaClientEvent    arg2,
               GdaParameterList *arg3,
               gpointer          user_data)

Parameters

gdaclient

the object which received the signal.

 

user_data

user data set when the signal handler was connected.

 

Flags: Run Last

See Also

GdaConnection.