function Condition::compile

Overrides ConditionInterface::compile

File

core/lib/Drupal/Core/Database/Query/Condition.php, line 200

Class

Condition

Generic class for a series of conditions in a query.

Namespace

Code

public function compile(Connection $connection, PlaceholderInterface $queryPlaceholder) {
    // Re-compile if this condition changed or if we are compiled against a
    // different query placeholder object.
    if ($this->changed || isset($this->queryPlaceholderIdentifier) && $this->queryPlaceholderIdentifier != $queryPlaceholder->uniqueIdentifier()) {
        $this->queryPlaceholderIdentifier = $queryPlaceholder->uniqueIdentifier();
        $condition_fragments = [];
        $arguments = [];
        $conditions = $this->conditions;
        $conjunction = $conditions['#conjunction'];
        unset($conditions['#conjunction']);
        foreach ($conditions as $condition) {
            // Process field.
            if ($condition['field'] instanceof ConditionInterface) {
                // Left hand part is a structured condition or a subquery. Compile,
                // put brackets around it (if it is a query), and collect any
                // arguments.
                $condition['field']->compile($connection, $queryPlaceholder);
                $field_fragment = (string) $condition['field'];
                if ($condition['field'] instanceof SelectInterface) {
                    $field_fragment = '(' . $field_fragment . ')';
                }
                $arguments += $condition['field']->arguments();
                // If the operator and value were not passed in to the
                // @see ConditionInterface::condition() method (and thus have the
                // default value as defined over there) it is assumed to be a valid
                // condition on its own: ignore the operator and value parts.
                $ignore_operator = $condition['operator'] === '=' && $condition['value'] === NULL;
            }
            elseif (!isset($condition['operator'])) {
                // Left hand part is a literal string added with the
                // @see ConditionInterface::where() method. Put brackets around
                // the snippet and collect the arguments from the value part.
                // Also ignore the operator and value parts.
                $field_fragment = '(' . $condition['field'] . ')';
                $arguments += $condition['value'];
                $ignore_operator = TRUE;
            }
            else {
                // Left hand part is a normal field. Add it as is.
                $field_fragment = $connection->escapeField($condition['field']);
                $ignore_operator = FALSE;
            }
            // Process operator.
            if ($ignore_operator) {
                $operator = [
                    'operator' => '',
                    'use_value' => FALSE,
                ];
            }
            else {
                // Remove potentially dangerous characters.
                // If something passed in an invalid character stop early, so we
                // don't rely on a broken SQL statement when we would just replace
                // those characters.
                if (stripos($condition['operator'], 'UNION') !== FALSE || strpbrk($condition['operator'], '[-\'"();') !== FALSE) {
                    $this->changed = TRUE;
                    $this->arguments = [];
                    // Provide a string which will result into an empty query result.
                    $this->stringVersion = '( AND 1 = 0 )';
                    // Conceptually throwing an exception caused by user input is bad
                    // as you result into a 'white screen of death', which depending on
                    // your webserver configuration can result into the assumption that
                    // your site is broken.
                    // On top of that the database API relies on __toString() which
                    // does not allow to throw exceptions.
                    trigger_error('Invalid characters in query operator: ' . $condition['operator'], E_USER_ERROR);
                    return;
                }
                // For simplicity, we convert all operators to a data structure to
                // allow to specify a prefix, a delimiter and such. Find the
                // associated data structure by first doing a database specific
                // lookup, followed by a specification according to the SQL standard.
                $operator = $connection->mapConditionOperator($condition['operator']);
                if (!isset($operator)) {
                    $operator = $this->mapConditionOperator($condition['operator']);
                }
                $operator += [
                    'operator' => $condition['operator'],
                ];
            }
            // Add defaults.
            $operator += [
                'prefix' => '',
                'postfix' => '',
                'delimiter' => '',
                'use_value' => TRUE,
            ];
            $operator_fragment = $operator['operator'];
            // Process value.
            $value_fragment = '';
            if ($operator['use_value']) {
                // For simplicity, we first convert to an array, so that we can handle
                // the single and multi value cases the same.
                if (!is_array($condition['value'])) {
                    if ($condition['value'] instanceof SelectInterface && ($operator['operator'] === 'IN' || $operator['operator'] === 'NOT IN')) {
                        // Special case: IN is followed by a single select query instead
                        // of a set of values: unset prefix and postfix to prevent double
                        // brackets.
                        $operator['prefix'] = '';
                        $operator['postfix'] = '';
                    }
                    $condition['value'] = [
                        $condition['value'],
                    ];
                }
                // Process all individual values.
                $value_fragment = [];
                foreach ($condition['value'] as $value) {
                    if ($value instanceof SelectInterface) {
                        // Right hand part is a subquery. Compile, put brackets around it
                        // and collect any arguments.
                        $value->compile($connection, $queryPlaceholder);
                        $value_fragment[] = '(' . (string) $value . ')';
                        $arguments += $value->arguments();
                    }
                    else {
                        // Right hand part is a normal value. Replace the value with a
                        // placeholder and add the value as an argument.
                        $placeholder = ':db_condition_placeholder_' . $queryPlaceholder->nextPlaceholder();
                        $value_fragment[] = $placeholder;
                        $arguments[$placeholder] = $value;
                    }
                }
                $value_fragment = $operator['prefix'] . implode($operator['delimiter'], $value_fragment) . $operator['postfix'];
            }
            // Concatenate the left hand part, operator and right hand part.
            $condition_fragments[] = trim(implode(' ', [
                $field_fragment,
                $operator_fragment,
                $value_fragment,
            ]));
        }
        // Concatenate all conditions using the conjunction and brackets around
        // the individual conditions to assure the proper evaluation order.
        $this->stringVersion = count($condition_fragments) > 1 ? '(' . implode(") {$conjunction} (", $condition_fragments) . ')' : implode($condition_fragments);
        $this->arguments = $arguments;
        $this->changed = FALSE;
    }
}