function _field_sql_storage_schema

Return the database schema for a field. This may contain one or more tables. Each table will contain the columns relevant for the specified field. Leave the $field's 'columns' and 'indexes' keys empty to get only the base schema.

Parameters

$field: The field structure for which to generate a database schema.

Return value

One or more tables representing the schema for the field.

File

modules/field/modules/field_sql_storage/field_sql_storage.module, line 151

Code

function _field_sql_storage_schema($field) {
    $deleted = $field['deleted'] ? 'deleted ' : '';
    $current = array(
        'description' => "Data storage for {$deleted}field {$field['id']} ({$field['field_name']})",
        'fields' => array(
            'entity_type' => array(
                'type' => 'varchar',
                'length' => 128,
                'not null' => TRUE,
                'default' => '',
                'description' => 'The entity type this data is attached to',
            ),
            'bundle' => array(
                'type' => 'varchar',
                'length' => 128,
                'not null' => TRUE,
                'default' => '',
                'description' => 'The field instance bundle to which this row belongs, used when deleting a field instance',
            ),
            'deleted' => array(
                'type' => 'int',
                'size' => 'tiny',
                'not null' => TRUE,
                'default' => 0,
                'description' => 'A boolean indicating whether this data item has been deleted',
            ),
            'entity_id' => array(
                'type' => 'int',
                'unsigned' => TRUE,
                'not null' => TRUE,
                'description' => 'The entity id this data is attached to',
            ),
            'revision_id' => array(
                'type' => 'int',
                'unsigned' => TRUE,
                'not null' => FALSE,
                'description' => 'The entity revision id this data is attached to, or NULL if the entity type is not versioned',
            ),
            // @todo Consider storing language as integer.
'language' => array(
                'type' => 'varchar',
                'length' => 32,
                'not null' => TRUE,
                'default' => '',
                'description' => 'The language for this data item.',
            ),
            'delta' => array(
                'type' => 'int',
                'unsigned' => TRUE,
                'not null' => TRUE,
                'description' => 'The sequence number for this data item, used for multi-value fields',
            ),
        ),
        'primary key' => array(
            'entity_type',
            'entity_id',
            'deleted',
            'delta',
            'language',
        ),
        'indexes' => array(
            'entity_type' => array(
                'entity_type',
            ),
            'bundle' => array(
                'bundle',
            ),
            'deleted' => array(
                'deleted',
            ),
            'entity_id' => array(
                'entity_id',
            ),
            'revision_id' => array(
                'revision_id',
            ),
            'language' => array(
                'language',
            ),
        ),
    );
    // If the target entity type uses a string for its entity ID then update
    // the fields entity_id and revision_id columns from INT to VARCHAR.
    if (!empty($field['entity_id_type']) && $field['entity_id_type'] === 'string') {
        $current['fields']['entity_id']['type'] = 'varchar';
        $current['fields']['entity_id']['length'] = 128;
        unset($current['fields']['entity_id']['unsigned']);
        $current['fields']['revision_id']['type'] = 'varchar';
        $current['fields']['revision_id']['length'] = 128;
        unset($current['fields']['revision_id']['unsigned']);
    }
    $field += array(
        'columns' => array(),
        'indexes' => array(),
        'foreign keys' => array(),
    );
    // Add field columns.
    foreach ($field['columns'] as $column_name => $attributes) {
        $real_name = _field_sql_storage_columnname($field['field_name'], $column_name);
        $current['fields'][$real_name] = $attributes;
    }
    // Add indexes.
    foreach ($field['indexes'] as $index_name => $columns) {
        $real_name = _field_sql_storage_indexname($field['field_name'], $index_name);
        foreach ($columns as $column_name) {
            // Indexes can be specified as either a column name or an array with
            // column name and length. Allow for either case.
            if (is_array($column_name)) {
                $current['indexes'][$real_name][] = array(
                    _field_sql_storage_columnname($field['field_name'], $column_name[0]),
                    $column_name[1],
                );
            }
            else {
                $current['indexes'][$real_name][] = _field_sql_storage_columnname($field['field_name'], $column_name);
            }
        }
    }
    // Add foreign keys.
    foreach ($field['foreign keys'] as $specifier => $specification) {
        $real_name = _field_sql_storage_indexname($field['field_name'], $specifier);
        $current['foreign keys'][$real_name]['table'] = $specification['table'];
        foreach ($specification['columns'] as $column_name => $referenced) {
            $sql_storage_column = _field_sql_storage_columnname($field['field_name'], $column_name);
            $current['foreign keys'][$real_name]['columns'][$sql_storage_column] = $referenced;
        }
    }
    // Construct the revision table.
    $revision = $current;
    $revision['description'] = "Revision archive storage for {$deleted}field {$field['id']} ({$field['field_name']})";
    $revision['primary key'] = array(
        'entity_type',
        'entity_id',
        'revision_id',
        'deleted',
        'delta',
        'language',
    );
    $revision['fields']['revision_id']['not null'] = TRUE;
    $revision['fields']['revision_id']['description'] = 'The entity revision id this data is attached to';
    return array(
        _field_sql_storage_tablename($field) => $current,
        _field_sql_storage_revision_tablename($field) => $revision,
    );
}