/**
* Implements PHP magic __toString method to convert the query to a string.
*
* @return string
* The prepared statement.
*/
public function __toString()
{
// Create a sanitized comment string to prepend to the query.
$comments = $this->connection->makeComment($this->comments);
// Expressions take priority over literal fields, so we process those first
// and remove any literal fields that conflict.
$fields = $this->fields;
$update_fields = array();
foreach ($this->expressionFields as $field => $data) {
$update_fields[] = $field . '=' . $data['expression'];
unset($fields[$field]);
}
$max_placeholder = 0;
foreach ($fields as $field => $value) {
$update_fields[] = $field . '=:db_update_placeholder_' . $max_placeholder++;
}
$query = $comments . 'UPDATE {' . $this->connection->escapeTable($this->table) . '} SET ' . implode(', ', $update_fields);
if (count($this->condition)) {
$this->condition->compile($this->connection, $this);
// There is an implicit string cast on $this->condition.
$query .= "\nWHERE " . $this->condition;
}
return $query;
}
public function __toString()
{
// Create a comments string to prepend to the query.
$comments = !empty($this->comments) ? '/* ' . implode('; ', $this->comments) . ' */ ' : '';
// SELECT
$query = $comments . 'SELECT ';
if ($this->distinct) {
$query .= 'DISTINCT ';
}
// FIELDS and EXPRESSIONS
$fields = array();
foreach ($this->tables as $alias => $table) {
if (!empty($table['all_fields'])) {
$fields[] = $this->connection->escapeTable($alias) . '.*';
}
}
foreach ($this->fields as $alias => $field) {
// Always use the AS keyword for field aliases, as some
// databases require it (e.g., PostgreSQL).
$fields[] = (isset($field['table']) ? $this->connection->escapeTable($field['table']) . '.' : '') . $this->connection->escapeField($field['field']) . ' AS ' . $this->connection->escapeAlias($field['alias']);
}
foreach ($this->expressions as $alias => $expression) {
$fields[] = $expression['expression'] . ' AS ' . $this->connection->escapeAlias($expression['alias']);
}
$query .= implode(', ', $fields);
// FROM - We presume all queries have a FROM, as any query that doesn't won't need the query builder anyway.
$query .= "\nFROM ";
foreach ($this->tables as $alias => $table) {
$query .= "\n";
if (isset($table['join type'])) {
$query .= $table['join type'] . ' JOIN ';
}
// If the table is a subquery, compile it and integrate it into this query.
if ($table['table'] instanceof SelectQueryInterface) {
// Run preparation steps on this sub-query before converting to string.
$subquery = $table['table'];
$subquery->preExecute();
$table_string = '(' . (string) $subquery . ')';
} else {
$table_string = '{' . $this->connection->escapeTable($table['table']) . '}';
}
// Don't use the AS keyword for table aliases, as some
// databases don't support it (e.g., Oracle).
$query .= $table_string . ' ' . $this->connection->escapeTable($table['alias']);
if (!empty($table['condition'])) {
$query .= ' ON ' . $table['condition'];
}
}
// WHERE
if (count($this->where)) {
// The following line will not generate placeholders correctly if there
// is a subquery. Fortunately, it is also called from getArguments() first
// so it's not a problem in practice... unless you try to call __toString()
// before calling getArguments(). That is a problem that we will have to
// fix in Drupal 8, because it requires more refactoring than we are
// able to do in Drupal 7.
// @todo Move away from __toString() For SelectQuery compilation at least.
$this->where->compile($this->connection, $this);
// There is an implicit string cast on $this->condition.
$query .= "\nWHERE " . $this->where;
}
// GROUP BY
if ($this->group) {
$query .= "\nGROUP BY " . implode(', ', $this->group);
}
// HAVING
if (count($this->having)) {
$this->having->compile($this->connection, $this);
// There is an implicit string cast on $this->having.
$query .= "\nHAVING " . $this->having;
}
// ORDER BY
if ($this->order) {
$query .= "\nORDER BY ";
$fields = array();
foreach ($this->order as $field => $direction) {
$fields[] = $field . ' ' . $direction;
}
$query .= implode(', ', $fields);
}
// RANGE
// There is no universal SQL standard for handling range or limit clauses.
// Fortunately, all core-supported databases use the same range syntax.
// Databases that need a different syntax can override this method and
// do whatever alternate logic they need to.
if (!empty($this->range)) {
$query .= "\nLIMIT " . (int) $this->range['length'] . " OFFSET " . (int) $this->range['start'];
}
// UNION is a little odd, as the select queries to combine are passed into
// this query, but syntactically they all end up on the same level.
if ($this->union) {
foreach ($this->union as $union) {
$query .= ' ' . $union['type'] . ' ' . (string) $union['query'];
}
}
if ($this->forUpdate) {
$query .= ' FOR UPDATE';
}
return $query;
}
