createImplicitManyToManyTableStatement method

String createImplicitManyToManyTableStatement(ImplicitManyToManyStorageDefinition storage)

Returns a join-table creation statement for storage.

Implementation

String createImplicitManyToManyTableStatement(
  ImplicitManyToManyStorageDefinition storage,
) {
  final sourceKeyFields = storage.sourceKeyFields
      .map((fieldName) => storage.sourceModel.findField(fieldName))
      .toList(growable: false);
  final targetKeyFields = storage.targetKeyFields
      .map((fieldName) => storage.targetModel.findField(fieldName))
      .toList(growable: false);
  if (sourceKeyFields.any((field) => field == null) ||
      targetKeyFields.any((field) => field == null)) {
    throw StateError(
      'Unable to resolve key fields for implicit many-to-many table ${storage.tableName}.',
    );
  }

  final sourceColumns = <String>[];
  for (var index = 0; index < sourceKeyFields.length; index++) {
    sourceColumns.add(
      '${_quoteIdentifier(storage.sourceJoinColumns[index])} ${postgresTypeForField(sourceKeyFields[index]!)}',
    );
  }
  final targetColumns = <String>[];
  for (var index = 0; index < targetKeyFields.length; index++) {
    targetColumns.add(
      '${_quoteIdentifier(storage.targetJoinColumns[index])} ${postgresTypeForField(targetKeyFields[index]!)}',
    );
  }
  final primaryKeyColumns = [
    ...storage.sourceJoinColumns,
    ...storage.targetJoinColumns,
  ].map(_quoteIdentifier).join(', ');
  final sourceJoinColumns = storage.sourceJoinColumns
      .map(_quoteIdentifier)
      .join(', ');
  final sourceTargetColumns = sourceKeyFields
      .map((field) => _quoteIdentifier(field!.databaseName))
      .join(', ');
  final targetJoinColumns = storage.targetJoinColumns
      .map(_quoteIdentifier)
      .join(', ');
  final targetTargetColumns = targetKeyFields
      .map((field) => _quoteIdentifier(field!.databaseName))
      .join(', ');

  return 'CREATE TABLE IF NOT EXISTS ${_quoteIdentifier(storage.tableName)} ('
      '${[...sourceColumns, ...targetColumns].join(', ')}, '
      'PRIMARY KEY ($primaryKeyColumns), '
      'CONSTRAINT ${_quoteIdentifier('${storage.tableName}_source_fkey')} '
      'FOREIGN KEY ($sourceJoinColumns) '
      'REFERENCES ${_quoteIdentifier(storage.sourceModel.databaseName)} ($sourceTargetColumns) '
      'ON DELETE CASCADE ON UPDATE CASCADE, '
      'CONSTRAINT ${_quoteIdentifier('${storage.tableName}_target_fkey')} '
      'FOREIGN KEY ($targetJoinColumns) '
      'REFERENCES ${_quoteIdentifier(storage.targetModel.databaseName)} ($targetTargetColumns) '
      'ON DELETE CASCADE ON UPDATE CASCADE'
      ')';
}