GdaDbIndex: libgda Reference Manual

## GdaDbIndex GdaDbIndex — Object to represent table index |

## Stability Level

Stable, unless otherwise indicated

## Functions

GQuark | gda_db_index_error_quark ()
GdaDbIndex * | gda_db_index_new ()
void | gda_db_index_set_unique ()
gboolean | gda_db_index_get_unique ()
void | gda_db_index_append_field ()
void | gda_db_index_remove_field ()
GSList * | gda_db_index_get_fields ()

## Properties

GdaDbTable * | table | Read / Write

## Types and Values

| GdaDbIndex
#define | GDA_TYPE_DB_INDEX
#define | GDA_DB_INDEX_ERROR

## Object Hierarchy

        GObject
        ╰── GdaDbBase
            ╰── GdaDbIndex

## Implemented Interfaces

GdaDbIndex implements GdaDdlModifiable.

## Includes

    #include <libgda/libgda.h>

## Description

The object GdaDbIndex holds information about index in a table. Just populate the information using index API, set table as property, execute `gda_ddl_modifiable_create()` method. This method executes all needed DB manopulations to add the target index to the DB. This can be illustarted by the following example:

    1
    2
    3
    4
    5
    6
    7
    8
    9
    10
    11
    12
    13
    14
    15
    16
    17
    18
    19
    20
    21
    22
    23
    24
    25
    GdaDbTable *table = gda_db_table_new();
    // Populate table as needed.
    GdaDbIndex      *index = gda_db_index_new ();
    GdaDbIndexField *field = gda_db_index_field_new ();
    GdaDbColumn     *fcol  = gda_db_column_new ();
    GError *error = NULL;

    gda_db_index_set_unique (index, TRUE);
    gda_db_base_set_name (GDA_DB_BASE (index), "MyIndex");

    gda_db_column_set_name (fcol, "name");

    gda_db_index_field_set_column (field, fcol);
    gda_db_index_field_set_sort_order (field, GDA_DB_INDEX_SORT_ORDER_ASC);
    gda_db_index_append_field (index, field);

    g_object_unref (fcol);
    g_object_unref (field);

    g_object_set (index, "table", table, NULL);

    res = gda_ddl_modifiable_create (GDA_DDL_MODIFIABLE(index), cnc, NULL, &error);

    if (!res)
      g_print("Error during index addition\n");

## Functions

### gda_db_index_error_quark ()

    GQuark
    gda_db_index_error_quark (void);

### gda_db_index_new ()

    GdaDbIndex *
    gda_db_index_new (void);

### gda_db_index_set_unique ()

    void
    gda_db_index_set_unique (GdaDbIndex *self,
                             gboolean val);

If `val` is `TRUE` a "UNIQUE" will be added to the INDEX CREATE command, e.g. CREATE UNIQUE INDEX ...

#### Parameters

self | GdaDbIndex instance |
val | if set to `TRUE` UNIQUE index type will be used. |

Since: 6.0

Stability Level: Stable

### gda_db_index_get_unique ()

    gboolean
    gda_db_index_get_unique (GdaDbIndex *self);

#### Parameters

self | instance os GdaDbIndex to use |

#### Returns

state for UNIQUE. This method will abort if `self` is `NULL`

Since: 6.0

Stability Level: Stable

### gda_db_index_append_field ()

    void
    gda_db_index_append_field (GdaDbIndex *self,
                               GdaDbIndexField *field);

Append to index filed to the current index instance, The `self` object will recieve full ownership of the field. After this call, the reference count for `field` will be increased and the instance of `fiels` must be destroyed by calling `g_object_unref()`

#### Parameters

self | an instance of GdaDbIndex |
field | a field to set |

Since: 6.0

Stability Level: Stable

### gda_db_index_remove_field ()

    void
    gda_db_index_remove_field (GdaDbIndex *self,
                               const gchar *name);

#### Parameters

self | instance of GdaDbIndex |
name | Name of the column where field should be removed. |

Since: 6.0

Stability Level: Stable

### gda_db_index_get_fields ()

    GSList *
    gda_db_index_get_fields (GdaDbIndex *self);

This function is thread safe, that is, `cnc` will be locked.

#### Parameters

self | an instance of GdaDbIndex |

#### Returns

A list of GdaDbIndexField.

[transfer none][nullable][element-type Gda.DbIndexField]

Since: 6.0

Stability Level: Stable

## Types and Values

### GdaDbIndex

    typedef struct _GdaDbIndex GdaDbIndex;

### GDA_TYPE_DB_INDEX

    #define GDA_TYPE_DB_INDEX (gda_db_index_get_type())

### GDA_DB_INDEX_ERROR

    #define GDA_DB_INDEX_ERROR gda_db_index_error_quark()

## Property Details

### The `“table”` property

      “table”                    GdaDbTable *

Table associated with index.

Owner: GdaDbIndex

Flags: Read / Write

## See Also

GdaDbTable, GdaDbCatalog