## MgDatabase

MgDatabase — Represents a database in the DBMS server

## Synopsis

    struct      MgDatabase;
    guint       mg_database_get_type            (void);
    GObject*    mg_database_new                 (MgConf *conf);
    MgConf*     mg_database_get_conf            (MgDatabase *mgdb);
    gboolean    mg_database_update_dbms_data    (MgDatabase *mgdb,
                                                 GError **error);
    void        mg_database_stop_update_dbms_data
                                                (MgDatabase *mgdb);
    GSList*     mg_database_get_tables          (MgDatabase *mgdb);
    MgDbTable*  mg_database_get_table_by_name   (MgDatabase *mgdb,
                                                 const gchar *name);
    MgDbTable*  mg_database_get_table_by_xml_id (MgDatabase *mgdb,
                                                 const gchar *xml_id);
    MgDbField*  mg_database_get_field_by_name   (MgDatabase *mgdb,
                                                 const gchar *fullname);
    MgDbField*  mg_database_get_field_by_xml_id (MgDatabase *mgdb,
                                                 const gchar *xml_id);
    MgDbSequence* mg_database_get_sequence_by_name
                                                (MgDatabase *mgdb,
                                                 const gchar *name);
    MgDbSequence* mg_database_get_sequence_by_xml_id
                                                (MgDatabase *mgdb,
                                                 const gchar *xml_id);
    MgDbSequence* mg_database_get_sequence_to_field
                                                (MgDatabase *mgdb,
                                                 MgDbField *field);
    void        mg_database_link_sequence       (MgDatabase *mgdb,
                                                 MgDbSequence *seq,
                                                 MgDbField *field);
    void        mg_database_unlink_sequence     (MgDatabase *mgdb,
                                                 MgDbSequence *seq,
                                                 MgDbField *field);
    void        mg_database_add_constraint      (MgDatabase *mgdb,
                                                 MgDbConstraint *cstr);
    GSList*     mg_database_get_all_constraints (MgDatabase *mgdb);
    GSList*     mg_database_get_all_fk_constraints
                                                (MgDatabase *mgdb);
    GSList*     mg_database_get_table_constraints
                                                (MgDatabase *mgdb,
                                                 MgDbTable *table);
    GSList*     mg_database_get_tables_fk_constraints
                                                (MgDatabase *mgdb,
                                                 MgDbTable *table1,
                                                 MgDbTable *table2,
                                                 gboolean table1_has_fk);

## Object Hierarchy

      GObject
       +----MgBase
             +----MgDatabase

## Implemented Interfaces

MgDatabase implements MgXmlStorage.

## Properties

      "prop"                 gpointer             : Read / Write

## Signal Prototypes

    "constraint-added"
                void        user_function      (MgDatabase *mgdatabase,
                                                gpointer arg1,
                                                gpointer user_data);
    "constraint-removed"
                void        user_function      (MgDatabase *mgdatabase,
                                                gpointer arg1,
                                                gpointer user_data);
    "constraint-updated"
                void        user_function      (MgDatabase *mgdatabase,
                                                gpointer arg1,
                                                gpointer user_data);
    "data-update-finished"
                void        user_function      (MgDatabase *mgdatabase,
                                                gpointer user_data);
    "data-update-started"
                void        user_function      (MgDatabase *mgdatabase,
                                                gpointer user_data);
    "field-added"
                void        user_function      (MgDatabase *mgdatabase,
                                                gpointer arg1,
                                                gpointer user_data);
    "field-removed"
                void        user_function      (MgDatabase *mgdatabase,
                                                gpointer arg1,
                                                gpointer user_data);
    "field-updated"
                void        user_function      (MgDatabase *mgdatabase,
                                                gpointer arg1,
                                                gpointer user_data);
    "fs-link-added"
                void        user_function      (MgDatabase *mgdatabase,
                                                gpointer arg1,
                                                gpointer arg2,
                                                gpointer user_data);
    "fs-link-removed"
                void        user_function      (MgDatabase *mgdatabase,
                                                gpointer arg1,
                                                gpointer arg2,
                                                gpointer user_data);
    "sequence-added"
                void        user_function      (MgDatabase *mgdatabase,
                                                gpointer arg1,
                                                gpointer user_data);
    "sequence-removed"
                void        user_function      (MgDatabase *mgdatabase,
                                                gpointer arg1,
                                                gpointer user_data);
    "sequence-updated"
                void        user_function      (MgDatabase *mgdatabase,
                                                gpointer arg1,
                                                gpointer user_data);
    "table-added"
                void        user_function      (MgDatabase *mgdatabase,
                                                gpointer arg1,
                                                gpointer user_data);
    "table-removed"
                void        user_function      (MgDatabase *mgdatabase,
                                                gpointer arg1,
                                                gpointer user_data);
    "table-updated"
                void        user_function      (MgDatabase *mgdatabase,
                                                gpointer arg1,
                                                gpointer user_data);
    "update-progress"
                void        user_function      (MgDatabase *mgdatabase,
                                                gpointer arg1,
                                                guint arg2,
                                                guint arg3,
                                                gpointer user_data);

## Description

This object manages an internal dictionnary mirroring the real database structure with objects such as MgDbTable (composed of MgDbfield objects) and MgDbConstraint.

Implements the MgXmlStorage interface.

## Details

### struct MgDatabase

    struct MgDatabase;

### mg_database_get_type ()

    guint       mg_database_get_type            (void);

Returns : | the type id

### mg_database_new ()

    GObject*    mg_database_new                 (MgConf *conf);

Creates a new MgDatabase object

`conf` : | a MgConf object
Returns : | the new object

### mg_database_get_conf ()

    MgConf*     mg_database_get_conf            (MgDatabase *mgdb);

Fetch the MgConf object to which the MgDatabase belongs.

`mgdb` : | a MgDatabase object
Returns : | the MgConf object

### mg_database_update_dbms_data ()

    gboolean    mg_database_update_dbms_data    (MgDatabase *mgdb,
                                                 GError **error);

Synchronises the Database representation with the database structure which is stored in the DBMS. For this operation to succeed, the connection to the DBMS server MUST be opened (using the corresponding MgServer object).

`mgdb` : | a MgDatabase object
`error` : | location to store error, or `NULL`
Returns : | TRUE if no error

### mg_database_stop_update_dbms_data ()

    void        mg_database_stop_update_dbms_data
                                                (MgDatabase *mgdb);

When the database updates its internal lists of DBMS objects, a call to this function will stop that update process. It has no effect when the database is not updating its DBMS data.

`mgdb` : | a MgDatabase object

### mg_database_get_tables ()

    GSList*     mg_database_get_tables          (MgDatabase *mgdb);

Get a list of all the tables within `mgdb`

`mgdb` : | a MgDatabase object
Returns : | a new list of all the MgDbTable objects

### mg_database_get_table_by_name ()

    MgDbTable*  mg_database_get_table_by_name   (MgDatabase *mgdb,
                                                 const gchar *name);

Get a reference to a MgDbTable using its name.

`mgdb` : | a MgDatabase object
`name` : | the name of the requested table
Returns : | The MgDbTable pointer or NULL if the requested table does not exist.

### mg_database_get_table_by_xml_id ()

    MgDbTable*  mg_database_get_table_by_xml_id (MgDatabase *mgdb,
                                                 const gchar *xml_id);

Get a reference to a MgDbTable using its XML id.

`mgdb` : | a MgDatabase object
`xml_id` : | the XML id of the requested table
Returns : | The MgDbTable pointer or NULL if the requested table does not exist.

### mg_database_get_field_by_name ()

    MgDbField*  mg_database_get_field_by_name   (MgDatabase *mgdb,
                                                 const gchar *fullname);

Get a reference to a MgDbField specifying the full name (table_name.field_name) of the requested field.

`mgdb` : | a MgDatabase object
`fullname` : | the name of the requested table field
Returns : | The MgDbField pointer or NULL if the requested field does not exist.

### mg_database_get_field_by_xml_id ()

    MgDbField*  mg_database_get_field_by_xml_id (MgDatabase *mgdb,
                                                 const gchar *xml_id);

Get a reference to a MgDbField specifying its XML id

`mgdb` : | a MgDatabase object
`xml_id` : | the XML id of the requested table field
Returns : | The MgDbField pointer or NULL if the requested field does not exist.

### mg_database_get_sequence_by_name ()

    MgDbSequence* mg_database_get_sequence_by_name
                                                (MgDatabase *mgdb,
                                                 const gchar *name);

Get a reference to a MgDbSequence specifying its name

`mgdb` : | a MgDatabase object
`name` : | the name of the requested sequence
Returns : | The MgDbSequence pointer or NULL if the requested sequence does not exist.

### mg_database_get_sequence_by_xml_id ()

    MgDbSequence* mg_database_get_sequence_by_xml_id
                                                (MgDatabase *mgdb,
                                                 const gchar *xml_id);

Get a reference to a MgDbSequence specifying its XML id.

`mgdb` : | a MgDatabase object
`xml_id` : | the XML id of the requested sequence
Returns : | The MgDbSequence pointer or NULL if the requested sequence does not exist.

### mg_database_get_sequence_to_field ()

    MgDbSequence* mg_database_get_sequence_to_field
                                                (MgDatabase *mgdb,
                                                 MgDbField *field);

Get a reference to a MgDbSequence which is "linked" to the MgDbField given as parameter. This "link" means that each new value of the field will be given by the returned sequence

`mgdb` : | a MgDatabase object
`field` : | a MgDbField object
Returns : | The MgDbSequence pointer or NULL if there is no sequence for this job.

### mg_database_link_sequence ()

    void        mg_database_link_sequence       (MgDatabase *mgdb,
                                                 MgDbSequence *seq,
                                                 MgDbField *field);

Tells the database that each new value of the field given as argument should be obtained from the specified sequence (this is usefull when the field is a simple primary key for example).

`mgdb` : | a MgDatabase object
`seq` : |
`field` : |

### mg_database_unlink_sequence ()

    void        mg_database_unlink_sequence     (MgDatabase *mgdb,
                                                 MgDbSequence *seq,
                                                 MgDbField *field);

Tells the database that each new value of the field given as argument should not be obtained from the specified sequence (this is usefull when the field is a simple primary key for example). This is the opposite of the `mg_database_link_sequence()` method.

`mgdb` : | a MgDatabase object
`seq` : |
`field` : |

### mg_database_add_constraint ()

    void        mg_database_add_constraint      (MgDatabase *mgdb,
                                                 MgDbConstraint *cstr);

Add the `cstr` constraint to the database. The `cstr` constraint is a user-defined constraint (which is not part of the database structure itself).

`mgdb` : | a MgDatabase object
`cstr` : | a MgDbConstraint

### mg_database_get_all_constraints ()

    GSList*     mg_database_get_all_constraints (MgDatabase *mgdb);

Get a list of all the constraints applied to the database. Constraints are represented as MgDbConstraint objects and represent any type of constraint.

`mgdb` : | a MgDatabase object
Returns : | a new list of the constraints

### mg_database_get_all_fk_constraints ()

    GSList*     mg_database_get_all_fk_constraints
                                                (MgDatabase *mgdb);

Get a list of all the constraints applied to the database which represent a foreign constrains. Constraints are represented as MgDbConstraint objects.

`mgdb` : | a MgDatabase object
Returns : | a new list of the constraints

### mg_database_get_table_constraints ()

    GSList*     mg_database_get_table_constraints
                                                (MgDatabase *mgdb,
                                                 MgDbTable *table);

Get all the constraints applicable to `table`

`mgdb` : | a MgDatabase object
`table` : | a MgDbTable, part of `mgdb`
Returns : | a new GSList of MgDbConstraint objects

### mg_database_get_tables_fk_constraints ()

    GSList*     mg_database_get_tables_fk_constraints
                                                (MgDatabase *mgdb,
                                                 MgDbTable *table1,
                                                 MgDbTable *table2,
                                                 gboolean table1_has_fk);

Get a list of all the constraints applied to the database which represent a foreign key constrains, between `table1` and `table2`. If `table1` or `table2` are `NULL`, then the returned foreign key constraints are the ones between any table and `table1` or `table2`.

Constraints are represented as MgDbConstraint objects.

`mgdb` : | a MgDatabase object
`table1` : | a MgDbTable, or `NULL`
`table2` : | a MgDbTable, or `NULL`
`table1_has_fk` : | TRUE if the returned constraints are the one for which `table1` contains the foreign key
Returns : | a new list of the constraints

## Properties

"`prop`" (gpointer : Read / Write) |

## Signals

### The "constraint-added" signal

    void        user_function                  (MgDatabase *mgdatabase,
                                                gpointer arg1,
                                                gpointer user_data);

`mgdatabase` : | the object which received the signal.
`arg1` : |
`user_data` : | user data set when the signal handler was connected.

### The "constraint-removed" signal

    void        user_function                  (MgDatabase *mgdatabase,
                                                gpointer arg1,
                                                gpointer user_data);

`mgdatabase` : | the object which received the signal.
`arg1` : |
`user_data` : | user data set when the signal handler was connected.

### The "constraint-updated" signal

    void        user_function                  (MgDatabase *mgdatabase,
                                                gpointer arg1,
                                                gpointer user_data);

`mgdatabase` : | the object which received the signal.
`arg1` : |
`user_data` : | user data set when the signal handler was connected.

### The "data-update-finished" signal

    void        user_function                  (MgDatabase *mgdatabase,
                                                gpointer user_data);

`mgdatabase` : | the object which received the signal.
`user_data` : | user data set when the signal handler was connected.

### The "data-update-started" signal

    void        user_function                  (MgDatabase *mgdatabase,
                                                gpointer user_data);

`mgdatabase` : | the object which received the signal.
`user_data` : | user data set when the signal handler was connected.

### The "field-added" signal

    void        user_function                  (MgDatabase *mgdatabase,
                                                gpointer arg1,
                                                gpointer user_data);

`mgdatabase` : | the object which received the signal.
`arg1` : |
`user_data` : | user data set when the signal handler was connected.

### The "field-removed" signal

    void        user_function                  (MgDatabase *mgdatabase,
                                                gpointer arg1,
                                                gpointer user_data);

`mgdatabase` : | the object which received the signal.
`arg1` : |
`user_data` : | user data set when the signal handler was connected.

### The "field-updated" signal

    void        user_function                  (MgDatabase *mgdatabase,
                                                gpointer arg1,
                                                gpointer user_data);

`mgdatabase` : | the object which received the signal.
`arg1` : |
`user_data` : | user data set when the signal handler was connected.

### The "fs-link-added" signal

    void        user_function                  (MgDatabase *mgdatabase,
                                                gpointer arg1,
                                                gpointer arg2,
                                                gpointer user_data);

`mgdatabase` : | the object which received the signal.
`arg1` : |
`arg2` : |
`user_data` : | user data set when the signal handler was connected.

### The "fs-link-removed" signal

    void        user_function                  (MgDatabase *mgdatabase,
                                                gpointer arg1,
                                                gpointer arg2,
                                                gpointer user_data);

`mgdatabase` : | the object which received the signal.
`arg1` : |
`arg2` : |
`user_data` : | user data set when the signal handler was connected.

### The "sequence-added" signal

    void        user_function                  (MgDatabase *mgdatabase,
                                                gpointer arg1,
                                                gpointer user_data);

`mgdatabase` : | the object which received the signal.
`arg1` : |
`user_data` : | user data set when the signal handler was connected.

### The "sequence-removed" signal

    void        user_function                  (MgDatabase *mgdatabase,
                                                gpointer arg1,
                                                gpointer user_data);

`mgdatabase` : | the object which received the signal.
`arg1` : |
`user_data` : | user data set when the signal handler was connected.

### The "sequence-updated" signal

    void        user_function                  (MgDatabase *mgdatabase,
                                                gpointer arg1,
                                                gpointer user_data);

`mgdatabase` : | the object which received the signal.
`arg1` : |
`user_data` : | user data set when the signal handler was connected.

### The "table-added" signal

    void        user_function                  (MgDatabase *mgdatabase,
                                                gpointer arg1,
                                                gpointer user_data);

`mgdatabase` : | the object which received the signal.
`arg1` : |
`user_data` : | user data set when the signal handler was connected.

### The "table-removed" signal

    void        user_function                  (MgDatabase *mgdatabase,
                                                gpointer arg1,
                                                gpointer user_data);

`mgdatabase` : | the object which received the signal.
`arg1` : |
`user_data` : | user data set when the signal handler was connected.

### The "table-updated" signal

    void        user_function                  (MgDatabase *mgdatabase,
                                                gpointer arg1,
                                                gpointer user_data);

`mgdatabase` : | the object which received the signal.
`arg1` : |
`user_data` : | user data set when the signal handler was connected.

### The "update-progress" signal

    void        user_function                  (MgDatabase *mgdatabase,
                                                gpointer arg1,
                                                guint arg2,
                                                guint arg3,
                                                gpointer user_data);

`mgdatabase` : | the object which received the signal.
`arg1` : |
`arg2` : |
`arg3` : |
`user_data` : | user data set when the signal handler was connected.