Add a unique key.

Parameters

string $table: The table to be altered.

string $name: The name of the key.

array $fields: An array of field names.

Overrides Schema::addUniqueKey

1 call to Schema::addUniqueKey()

Schema::_createKeys in core/modules/pgsql/src/Driver/Database/pgsql/Schema.php

Adds keys for an SQL table.

File

core/modules/pgsql/src/Driver/Database/pgsql/Schema.php, line 815

Class

Schema

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

Namespace

Drupal\pgsql\Driver\Database\pgsql

Code

public function addUniqueKey($table, $name, $fields) {
  if (!$this->tableExists($table)) {
    throw new SchemaObjectDoesNotExistException("Cannot add unique key '{$name}' to table '{$table}': table doesn't exist.");
  }
  if ($this->constraintExists($table, $name . '__key')) {
    throw new SchemaObjectExistsException("Cannot add unique key '{$name}' to table '{$table}': unique key already exists.");
  }
  // Use the createPrimaryKeySql(), which already discards any prefix lengths
  // passed as part of the key column specifiers. (Postgres doesn't support
  // setting a prefix length for PRIMARY or UNIQUE indices.)
  $this->executeDdlStatement('ALTER TABLE {' . $table . '} ADD CONSTRAINT ' . $this->ensureIdentifiersLength($table, $name, 'key') . ' UNIQUE (' . $this->createPrimaryKeySql($fields) . ')');
  $this->resetTableInformation($table);
}

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