/common/libraries/php/storage/mdb2/condition_translator.class.php

<?php

namespace common\libraries;



use Exception;



/**
 * @package common.libraries.storage.mdb2
 * @author Hans De Bisschop
 */



class Mdb2ConditionTranslator extends ConditionTranslator

{



    /**
     * Translates an aggregate condition to a SQL WHERE clause.
     * @param AggregateCondition $condition The AggregateCondition object.
     * @param array $parameters A reference to the query's parameter list.
     * @param boolean $storage_unit Whether or not to
     * prefix learning
     * object properties
     * to avoid collisions.
     * @return string The WHERE clause.
     */

    function translate_aggregate_condition($aggregate_condition)

    {

        $string = '';



        if ($aggregate_condition instanceof AndCondition || $aggregate_condition instanceof OrCondition)

        {

            $condition_translations = array();

            $count = 0;



            foreach ($aggregate_condition->get_conditions() as $key => $condition)

            {

                $count ++;

                $translation = $this->translate($condition);



                if (! empty($translation))

                {

                    $condition_translations[] = $translation;

                }

            }



            if (count($condition_translations) > 0)

            {

                $string = '(' . implode($aggregate_condition->get_operator(), $condition_translations) . ')';

            }

        }

        elseif ($aggregate_condition instanceof NotCondition)

        {

            $string .= 'NOT (';

            $string .= $this->translate($aggregate_condition->get_condition());

            $string .= $this->strings[] = ')';

        }

        else

        {

            die('Cannot translate aggregate condition');

        }



        return $string;

    }



    /**
     * Translates an in condition to a SQL WHERE clause.
     * @param InCondition $condition The InCondition object.
     * @param array $parameters A reference to the query's parameter list.
     * @param boolean $storage_unit Whether or not to
     * prefix learning
     * object properties
     * to avoid collisions.
     * @return string The WHERE clause.
     */

    function translate_in_condition($condition)

    {

        $storage_unit = $this->get_storage_unit();

        $condition_storage_unit = $condition->get_storage_unit();



        if (! is_null($condition_storage_unit))

        {

            if ($condition->is_alias())

            {

                $storage_unit = $condition_storage_unit;

            }

            else

            {

                $storage_unit = $this->get_data_manager()->get_alias($condition_storage_unit);

            }

        }



        if ($condition instanceof InCondition)

        {

            $name = $condition->get_name();

            $values = $condition->get_values();



            if (! is_array($values))

            {

                $values = array($values);

            }



            if (count($values) > 0)

            {

                $where_clause = array();

                $where_clause[] = $this->get_data_manager()->escape_column_name($name, $storage_unit) . ' IN (';



                $placeholders = array();

                foreach ($values as $value)

                {

                    $placeholders[] = $this->get_data_manager()->quote($value);

                }



                $where_clause[] = implode(',', $placeholders);

                $where_clause[] = ')';

                return implode('', $where_clause);

            }

            else

            {

                return 'true=false';

            }

        }

        else

        {

            die('Cannot translate in condition');

        }

    }



    function translate_subselect_condition($condition)

    {

        if ($condition instanceof SubselectCondition)

        {

            $storage_unit = $this->get_storage_unit();



            $name = $condition->get_name();

            $value = $condition->get_value();

            $table = $condition->get_storage_unit_value();

            $name_table = $condition->get_storage_unit_name();



            if ($condition->get_data_manager())

            {

                $etable = $condition->get_data_manager()->escape_table_name($table);

            }

            else

            {

                $etable = $this->get_data_manager()->escape_table_name($table);

            }



            $sub_condition = $condition->get_condition();



            $alias = $this->get_data_manager()->get_alias($table);

            $alias_name = null;

            if ($name_table)

            {

                $alias_name = $this->get_data_manager()->get_alias($name_table);

            }



            $this->set_storage_unit($alias);

            $string = $this->get_data_manager()->escape_column_name($name, $alias_name) . ' IN ( SELECT ' . $this->get_data_manager()->escape_column_name($value, $alias) . ' FROM ' . $etable . ' AS ' . $alias;



            if ($sub_condition)

            {

                $string .= ' WHERE ';

                $string .= $this->translate($sub_condition);

            }



            $string .= ')';

            $this->set_storage_unit($storage_unit);

        }

        else

        {

            die('Cannot translate in condition');

        }



        return $string;

    }



    /**
     * Translates a simple condition to a SQL WHERE clause.
     * @param Condition $condition The Condition object.
     * @param array $parameters A reference to the query's parameter list.
     * @param boolean $storage_unit Whether or not to
     * prefix learning
     * object properties
     * to avoid collisions.
     * @return string The WHERE clause.
     */

    function translate_simple_condition($condition)

    {

        $storage_unit = $this->get_storage_unit();

        $data_manager = $this->get_data_manager();



        $name = $condition->get_name();

        $condition_storage_unit = $condition->get_storage_unit();



        if (! is_null($condition_storage_unit))

        {

            if ($condition->is_alias())

            {

                $storage_unit = $condition_storage_unit;

            }

            else

            {

                $storage_unit = $this->get_data_manager()->get_alias($condition_storage_unit);

            }

        }



        if ($condition instanceof EqualityCondition)

        {

            $value = $condition->get_value();



            if (is_null($value))

            {

                return $this->get_data_manager()->escape_column_name($name, $storage_unit) . ' IS NULL';

            }



            return $this->get_data_manager()->escape_column_name($name, $storage_unit) . ' = ' . $this->get_data_manager()->quote($value);

        }

        elseif ($condition instanceof InequalityCondition)

        {

            $value = $condition->get_value();



            switch ($condition->get_operator())

            {

                case InequalityCondition :: GREATER_THAN :

                    $operator = '>';

                    break;

                case InequalityCondition :: GREATER_THAN_OR_EQUAL :

                    $operator = '>=';

                    break;

                case InequalityCondition :: LESS_THAN :

                    $operator = '<';

                    break;

                case InequalityCondition :: LESS_THAN_OR_EQUAL :

                    $operator = '<=';

                    break;

                default :

                    dump($condition);

                    die('Unknown operator for inequality condition');

            }



            return $this->get_data_manager()->escape_column_name($name, $storage_unit) . ' ' . $operator . ' ' . $this->get_data_manager()->quote($value);

        }

        elseif ($condition instanceof PatternMatchCondition)

        {

            return $this->get_data_manager()->escape_column_name($condition->get_name(), $storage_unit) . ' LIKE ' . $this->get_data_manager()->quote($this->translate_search_string($condition->get_pattern()));

        }

        else

        {

            return $condition; //die('Cannot translate condition');
        }

    }



    /**
     * Translates a string with wildcard characters "?" (single character)
     * and "*" (any character sequence) to a SQL pattern for use in a LIKE
     * condition. Should be suitable for any SQL flavor.
     * @param string $string The string that contains wildcard characters.
     * @return string The escaped string.
     */

    function translate_search_string($string)

    {

        /*
		 ======================================================================
		 * A brief explanation of these regexps:
		 * - The first one escapes SQL wildcard characters, thus prefixing
		 *   %, ', \ and _ with a backslash.
		 * - The second one replaces asterisks that are not prefixed with a
		 *   backslash (which escapes them) with the SQL equivalent, namely a
		 *   percent sign.
		 * - The third one is similar to the second: it replaces question
		 *   marks that are not escaped with the SQL equivalent _.
		 ======================================================================
		 */

        return preg_replace(array('/([%\'\\\\_])/e', '/(?<!\\\\)\*/', '/(?<!\\\\)\?/'), array("'\\\\\\\\' . '\\1'",

                '%', '_'), $string);

    }



    function render_query($condition, $add_where = true)

    {

        return ($add_where ? ' WHERE ' : '') . $this->translate($condition);

    }



}

?>