function DatabaseSchema_pgsql::changeField

Overrides DatabaseSchema::changeField

File

includes/database/pgsql/schema.inc, line 703

Class

DatabaseSchema_pgsql

Code

public function changeField($table, $field, $field_new, $spec, $new_keys = array()) {
    if (!$this->fieldExists($table, $field)) {
        throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot change the definition of field @table.@name: field doesn't exist.", array(
            '@table' => $table,
            '@name' => $field,
        )));
    }
    if ($field != $field_new && $this->fieldExists($table, $field_new)) {
        throw new DatabaseSchemaObjectExistsException(t("Cannot rename field @table.@name to @name_new: target field already exists.", array(
            '@table' => $table,
            '@name' => $field,
            '@name_new' => $field_new,
        )));
    }
    $spec = $this->processField($spec);
    // We need to typecast the new column to best be able to transfer the data
    // Schema_pgsql::getFieldTypeMap() will return possibilities that are not
    // 'cast-able' such as 'serial' - so they need to be casted int instead.
    if (in_array($spec['pgsql_type'], array(
        'serial',
        'bigserial',
        'numeric',
    ))) {
        $typecast = 'int';
    }
    else {
        $typecast = $spec['pgsql_type'];
    }
    if (in_array($spec['pgsql_type'], array(
        'varchar',
        'character',
        'text',
    )) && isset($spec['length'])) {
        $typecast .= '(' . $spec['length'] . ')';
    }
    elseif (isset($spec['precision']) && isset($spec['scale'])) {
        $typecast .= '(' . $spec['precision'] . ', ' . $spec['scale'] . ')';
    }
    // Remove old check constraints.
    $field_info = $this->queryFieldInformation($table, $field);
    foreach ($field_info as $check) {
        $this->connection
            ->query('ALTER TABLE {' . $table . '} DROP CONSTRAINT "' . $check . '"');
    }
    // Remove old default.
    $this->fieldSetNoDefault($table, $field);
    $this->connection
        ->query('ALTER TABLE {' . $table . '} ALTER "' . $field . '" TYPE ' . $typecast . ' USING "' . $field . '"::' . $typecast);
    if (isset($spec['not null'])) {
        if ($spec['not null']) {
            $nullaction = 'SET NOT NULL';
        }
        else {
            $nullaction = 'DROP NOT NULL';
        }
        $this->connection
            ->query('ALTER TABLE {' . $table . '} ALTER "' . $field . '" ' . $nullaction);
    }
    if (in_array($spec['pgsql_type'], array(
        'serial',
        'bigserial',
    ))) {
        // Type "serial" is known to PostgreSQL, but *only* during table creation,
        // not when altering. Because of that, the sequence needs to be created
        // and initialized by hand.
        $seq = "{" . $table . "}_" . $field_new . "_seq";
        $this->connection
            ->query("CREATE SEQUENCE " . $seq);
        // Set sequence to maximal field value to not conflict with existing
        // entries.
        $this->connection
            ->query("SELECT setval('" . $seq . "', MAX(\"" . $field . '")) FROM {' . $table . "}");
        $this->connection
            ->query('ALTER TABLE {' . $table . '} ALTER "' . $field . '" SET DEFAULT nextval(\'' . $seq . '\')');
    }
    // Rename the column if necessary.
    if ($field != $field_new) {
        $this->connection
            ->query('ALTER TABLE {' . $table . '} RENAME "' . $field . '" TO "' . $field_new . '"');
    }
    // Add unsigned check if necessary.
    if (!empty($spec['unsigned'])) {
        $this->connection
            ->query('ALTER TABLE {' . $table . '} ADD CHECK ("' . $field_new . '" >= 0)');
    }
    // Add default if necessary.
    if (isset($spec['default'])) {
        $this->fieldSetDefault($table, $field_new, $spec['default']);
    }
    // Change description if necessary.
    if (!empty($spec['description'])) {
        $this->connection
            ->query('COMMENT ON COLUMN {' . $table . '}."' . $field_new . '" IS ' . $this->prepareComment($spec['description']));
    }
    if (isset($new_keys)) {
        $this->_createKeys($table, $new_keys);
    }
}