Prepares a query string and returns the prepared statement.
This method caches prepared statements, reusing them when possible. It also prefixes tables names enclosed in curly-braces.
$query: The query string as SQL, with curly-braces surrounding the table names.
DatabaseStatementInterface A PDO prepared statement ready for its execute() method.
Overrides DatabaseConnection::prepareQuery
public function prepareQuery($query) {
// mapConditionOperator converts LIKE operations to ILIKE for consistency
// with MySQL. However, Postgres does not support ILIKE on bytea (blobs)
// fields.
// To make the ILIKE operator work, we type-cast bytea fields into text.
// @todo This workaround only affects bytea fields, but the involved field
// types involved in the query are unknown, so there is no way to
// conditionally execute this for affected queries only.
return parent::prepareQuery(preg_replace('/ ([^ ]+) +(I*LIKE|NOT +I*LIKE) /i', ' ${1}::text ${2} ', $query));
}