![]() |
![]() |
![]() |
Libgnomedb Reference Manual | ![]() |
---|---|---|---|---|
GnomeDbConstraint; enum GnomeDbConstraintType; enum GnomeDbConstraintFkAction; GType gnome_db_constraint_get_type (void); GObject* gnome_db_constraint_new (GnomeDbTable *table, GnomeDbConstraintType type); GnomeDbConstraintType gnome_db_constraint_get_constraint_type (GnomeDbConstraint *cstr); gboolean gnome_db_constraint_equal (GnomeDbConstraint *cstr1, GnomeDbConstraint *cstr2); GnomeDbTable* gnome_db_constraint_get_table (GnomeDbConstraint *cstr); gboolean gnome_db_constraint_uses_field (GnomeDbConstraint *cstr, GnomeDbTableField *field); void gnome_db_constraint_pkey_set_fields (GnomeDbConstraint *cstr, const GSList *fields); GSList* gnome_db_constraint_pkey_get_fields (GnomeDbConstraint *cstr); void gnome_db_constraint_fkey_set_fields (GnomeDbConstraint *cstr, const GSList *pairs); GnomeDbTable* gnome_db_constraint_fkey_get_ref_table (GnomeDbConstraint *cstr); GSList* gnome_db_constraint_fkey_get_fields (GnomeDbConstraint *cstr); void gnome_db_constraint_fkey_set_actions (GnomeDbConstraint *cstr, GnomeDbConstraintFkAction on_update, GnomeDbConstraintFkAction on_delete); void gnome_db_constraint_fkey_get_actions (GnomeDbConstraint *cstr, GnomeDbConstraintFkAction *on_update, GnomeDbConstraintFkAction *on_delete); void gnome_db_constraint_unique_set_fields (GnomeDbConstraint *cstr, const GSList *fields); GSList* gnome_db_constraint_unique_get_fields (GnomeDbConstraint *cstr); void gnome_db_constraint_not_null_set_field (GnomeDbConstraint *cstr, GnomeDbTableField *field); GnomeDbTableField* gnome_db_constraint_not_null_get_field (GnomeDbConstraint *cstr);
"templ-signal" void user_function (GnomeDbConstraint *dbconstraint, gpointer user_data) : Run first
Any type of constraint in a database is represented by one instance of the class (see the possible types of constraints). As some constraints may not depend exclusively on a table, all the constraints are attached to the database itself.
It implements the GnomeDbXmlStorage and GnomeDbReferer interfaces.
typedef enum { CONSTRAINT_PRIMARY_KEY, CONSTRAINT_FOREIGN_KEY, CONSTRAINT_UNIQUE, CONSTRAINT_NOT_NULL, CONSTRAINT_CHECK_EXPR, CONSTRAINT_UNKNOWN } GnomeDbConstraintType;
typedef enum { CONSTRAINT_FK_ACTION_CASCADE, CONSTRAINT_FK_ACTION_SET_NULL, CONSTRAINT_FK_ACTION_SET_DEFAULT, CONSTRAINT_FK_ACTION_SET_VALUE, CONSTRAINT_FK_ACTION_NO_ACTION } GnomeDbConstraintFkAction;
GObject* gnome_db_constraint_new (GnomeDbTable *table, GnomeDbConstraintType type);
Creates a new GnomeDbConstraint object
table : |
the GnomeDbTable to which the constraint is attached |
type : |
the type of constraint |
Returns : | the new object |
GnomeDbConstraintType gnome_db_constraint_get_constraint_type (GnomeDbConstraint *cstr);
Get the type of constraint the cstr
object represents
cstr : |
a GnomeDbConstraint object |
Returns : | the constraint type |
gboolean gnome_db_constraint_equal (GnomeDbConstraint *cstr1, GnomeDbConstraint *cstr2);
Compares two GnomeDbConstraint objects to see if they are equal, without taking into account the name of the constraints or weather they are user or system defined
cstr1 : |
the first GnomeDbConstraint to compare |
cstr2 : |
the second GnomeDbConstraint to compare |
Returns : | TRUE if the two constraints are equal and FALSE otherwise |
GnomeDbTable* gnome_db_constraint_get_table (GnomeDbConstraint *cstr);
Get the table to which the constraint is attached
cstr : |
a GnomeDbConstraint object |
Returns : | the GnomeDbTable |
gboolean gnome_db_constraint_uses_field (GnomeDbConstraint *cstr, GnomeDbTableField *field);
Tests if field
is part of the cstr
constraint
cstr : |
a GnomeDbConstraint object |
field : |
a GnomeDbTableField object |
Returns : | TRUE if cstr uses field
|
void gnome_db_constraint_pkey_set_fields (GnomeDbConstraint *cstr, const GSList *fields);
Sets the fields which make the primary key represented by cstr
. All the fields
must belong to the same GnomeDbTable to which the constraint is attached
cstr : |
a GnomeDbConstraint object |
fields : |
a list of GnomeDbTableField objects |
GSList* gnome_db_constraint_pkey_get_fields (GnomeDbConstraint *cstr);
Get the list of fields composing the primary key constraint which cstr
represents. The
returned list is allocated and must be de-allocated by the caller.
cstr : |
a GnomeDbConstraint object |
Returns : | a new list of fields |
void gnome_db_constraint_fkey_set_fields (GnomeDbConstraint *cstr, const GSList *pairs);
Sets the field pairs which make the foreign key represented by cstr
. All the field pairs
must list a field which belong to the same GnomeDbTable to which the constraint is attached
and a field which belongs to a GnomeDbTable which is different from the one just mentionned and which
is within the same database.
The pairs are of type GnomeDbConstraintFkeyPair.
cstr : |
a GnomeDbConstraint object |
pairs : |
a list of GnomeDbTableField objects |
GnomeDbTable* gnome_db_constraint_fkey_get_ref_table (GnomeDbConstraint *cstr);
Get the GnomeDbTable at the other end of the foreign key relation represented by this constraint
cstr : |
a GnomeDbConstraint object |
Returns : | the GnomeDbTable |
GSList* gnome_db_constraint_fkey_get_fields (GnomeDbConstraint *cstr);
Get the list of field pairs composing the foreign key constraint which cstr
represents. In the returned
list, each pair item is allocated and it's up to the caller to free the list and each pair, and the
reference count for each pointer to GObjects in each pair is NOT INCREASED, which means the caller of this
function DOES NOT hold any reference on the mentionned GObjects (if he needs to, it has to call g_object_ref()
)
cstr : |
a GnomeDbConstraint object |
Returns : | a new list of GnomeDbConstraintFkeyPair pairs |
void gnome_db_constraint_fkey_set_actions (GnomeDbConstraint *cstr, GnomeDbConstraintFkAction on_update, GnomeDbConstraintFkAction on_delete);
Sets the actions undertaken by the DBMS when some actions occur on the referenced data
cstr : |
a GnomeDbConstraint object |
on_update : |
the action undertaken when an UPDATE occurs |
on_delete : |
the action undertaken when a DELETE occurs |
void gnome_db_constraint_fkey_get_actions (GnomeDbConstraint *cstr, GnomeDbConstraintFkAction *on_update, GnomeDbConstraintFkAction *on_delete);
Get the actions undertaken by the DBMS when some actions occur on the referenced data
cstr : |
a GnomeDbConstraint object |
on_update : |
an address to store the action undertaken when an UPDATE occurs |
on_delete : |
an address to store the action undertaken when a DELETE occurs |
void gnome_db_constraint_unique_set_fields (GnomeDbConstraint *cstr, const GSList *fields);
cstr : |
a GnomeDbConstraint object |
fields : |
GSList* gnome_db_constraint_unique_get_fields (GnomeDbConstraint *cstr);
Get the list of fields represented by this UNIQUE constraint. It's up to the caller to free the list.
cstr : |
a GnomeDbConstraint object |
Returns : | a new list of fields |
void gnome_db_constraint_not_null_set_field (GnomeDbConstraint *cstr, GnomeDbTableField *field);
cstr : |
|
field : |
GnomeDbTableField* gnome_db_constraint_not_null_get_field (GnomeDbConstraint *cstr);
cstr : |
|
Returns : |
void user_function (GnomeDbConstraint *dbconstraint, gpointer user_data) : Run first
dbconstraint : |
the object which received the signal. |
user_data : |
user data set when the signal handler was connected. |