function Schema::addField

Overrides Schema::addField

File

core/modules/sqlite/src/Driver/Database/sqlite/Schema.php, line 311

Class

Schema

SQLite implementation of \Drupal\Core\Database\Schema.

Namespace

Code

public function addField($table, $field, $specification, $keys_new = []) {
    if (!$this->tableExists($table)) {
        throw new SchemaObjectDoesNotExistException("Cannot add field '{$table}.{$field}': table doesn't exist.");
    }
    if ($this->fieldExists($table, $field)) {
        throw new SchemaObjectExistsException("Cannot add field '{$table}.{$field}': field already exists.");
    }
    if (isset($keys_new['primary key']) && in_array($field, $keys_new['primary key'], TRUE)) {
        $this->ensureNotNullPrimaryKey($keys_new['primary key'], [
            $field => $specification,
        ]);
    }
    // SQLite doesn't have a full-featured ALTER TABLE statement. It only
    // supports adding new fields to a table, in some simple cases. In most
    // cases, we have to create a new table and copy the data over.
    if (empty($keys_new) && (empty($specification['not null']) || isset($specification['default']))) {
        // When we don't have to create new keys and we are not creating a
        // NOT NULL column without a default value, we can use the quicker version.
        $query = 'ALTER TABLE {' . $table . '} ADD ' . $this->createFieldSql($field, $this->processField($specification));
        $this->connection
            ->query($query);
        // Apply the initial value if set.
        if (isset($specification['initial_from_field'])) {
            if (isset($specification['initial'])) {
                $expression = 'COALESCE(' . $specification['initial_from_field'] . ', :default_initial_value)';
                $arguments = [
                    ':default_initial_value' => $specification['initial'],
                ];
            }
            else {
                $expression = $specification['initial_from_field'];
                $arguments = [];
            }
            $this->connection
                ->update($table)
                ->expression($field, $expression, $arguments)
                ->execute();
        }
        elseif (isset($specification['initial'])) {
            $this->connection
                ->update($table)
                ->fields([
                $field => $specification['initial'],
            ])
                ->execute();
        }
    }
    else {
        // We cannot add the field directly. Use the slower table alteration
        // method, starting from the old schema.
        $old_schema = $this->introspectSchema($table);
        $new_schema = $old_schema;
        // Add the new field.
        $new_schema['fields'][$field] = $specification;
        // Build the mapping between the old fields and the new fields.
        $mapping = [];
        if (isset($specification['initial_from_field'])) {
            // If we have an initial value, copy it over.
            if (isset($specification['initial'])) {
                $expression = 'COALESCE(' . $specification['initial_from_field'] . ', :default_initial_value)';
                $arguments = [
                    ':default_initial_value' => $specification['initial'],
                ];
            }
            else {
                $expression = $specification['initial_from_field'];
                $arguments = [];
            }
            $mapping[$field] = [
                'expression' => $expression,
                'arguments' => $arguments,
            ];
        }
        elseif (isset($specification['initial'])) {
            // If we have an initial value, copy it over.
            $mapping[$field] = [
                'expression' => ':newfieldinitial',
                'arguments' => [
                    ':newfieldinitial' => $specification['initial'],
                ],
            ];
        }
        else {
            // Else use the default of the field.
            $mapping[$field] = NULL;
        }
        // Add the new indexes.
        $new_schema = array_merge($new_schema, $keys_new);
        $this->alterTable($table, $old_schema, $new_schema, $mapping);
    }
}