public function Schema::queryFieldInformation in Drupal 8

Same name and namespace in other branches

9 core/lib/Drupal/Core/Database/Driver/pgsql/Schema.php \Drupal\Core\Database\Driver\pgsql\Schema::queryFieldInformation()

Fetches the list of constraints used on a field.

We introspect the database to collect the information required by field alteration.

Parameters

string $table: The non-prefixed name of the table.

string $field: The name of the field.

string $constraint_type: (optional) The type of the constraint. This can be one of the following:

c: check constraint;
f: foreign key constraint;
p: primary key constraint;
u: unique constraint;
t: constraint trigger;
x: exclusion constraint.

Defaults to 'c' for a CHECK constraint. @see https://www.postgresql.org/docs/current/catalog-pg-constraint.html

Return value

array An array containing all the constraint names for the field.

1 call to Schema::queryFieldInformation()

Schema::changeField in core/lib/Drupal/Core/Database/Driver/pgsql/Schema.php: Change a field definition.

File

core/lib/Drupal/Core/Database/Driver/pgsql/Schema.php, line 231

Class

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

Namespace

Drupal\Core\Database\Driver\pgsql

Code

public function queryFieldInformation($table, $field, $constraint_type = 'c') {
  assert(in_array($constraint_type, [
    'c',
    'f',
    'p',
    'u',
    't',
    'x',
  ]));
  $prefixInfo = $this
    ->getPrefixInfo($table, TRUE);

  // Split the key into schema and table for querying.
  $schema = $prefixInfo['schema'];
  $table_name = $prefixInfo['table'];
  $this->connection
    ->addSavepoint();
  try {
    $checks = $this->connection
      ->query("SELECT conname FROM pg_class cl INNER JOIN pg_constraint co ON co.conrelid = cl.oid INNER JOIN pg_attribute attr ON attr.attrelid = cl.oid AND attr.attnum = ANY (co.conkey) INNER JOIN pg_namespace ns ON cl.relnamespace = ns.oid WHERE co.contype = :constraint_type AND ns.nspname = :schema AND cl.relname = :table AND attr.attname = :column", [
      ':constraint_type' => $constraint_type,
      ':schema' => $schema,
      ':table' => $table_name,
      ':column' => $field,
    ]);
  } catch (\Exception $e) {
    $this->connection
      ->rollbackSavepoint();
    throw $e;
  }
  $this->connection
    ->releaseSavepoint();
  $field_information = $checks
    ->fetchCol();
  return $field_information;
}

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