web/Zend/Db/Select.php
changeset 0 4eba9c11703f
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/web/Zend/Db/Select.php	Mon Dec 13 18:29:26 2010 +0100
@@ -0,0 +1,1351 @@
+<?php
+/**
+ * Zend Framework
+ *
+ * LICENSE
+ *
+ * This source file is subject to the new BSD license that is bundled
+ * with this package in the file LICENSE.txt.
+ * It is also available through the world-wide-web at this URL:
+ * http://framework.zend.com/license/new-bsd
+ * If you did not receive a copy of the license and are unable to
+ * obtain it through the world-wide-web, please send an email
+ * to license@zend.com so we can send you a copy immediately.
+ *
+ * @category   Zend
+ * @package    Zend_Db
+ * @subpackage Select
+ * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)
+ * @license    http://framework.zend.com/license/new-bsd     New BSD License
+ * @version    $Id: Select.php 23254 2010-10-26 12:49:23Z matthew $
+ */
+
+
+/**
+ * @see Zend_Db_Adapter_Abstract
+ */
+require_once 'Zend/Db/Adapter/Abstract.php';
+
+/**
+ * @see Zend_Db_Expr
+ */
+require_once 'Zend/Db/Expr.php';
+
+
+/**
+ * Class for SQL SELECT generation and results.
+ *
+ * @category   Zend
+ * @package    Zend_Db
+ * @subpackage Select
+ * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)
+ * @license    http://framework.zend.com/license/new-bsd     New BSD License
+ */
+class Zend_Db_Select
+{
+
+    const DISTINCT       = 'distinct';
+    const COLUMNS        = 'columns';
+    const FROM           = 'from';
+    const UNION          = 'union';
+    const WHERE          = 'where';
+    const GROUP          = 'group';
+    const HAVING         = 'having';
+    const ORDER          = 'order';
+    const LIMIT_COUNT    = 'limitcount';
+    const LIMIT_OFFSET   = 'limitoffset';
+    const FOR_UPDATE     = 'forupdate';
+
+    const INNER_JOIN     = 'inner join';
+    const LEFT_JOIN      = 'left join';
+    const RIGHT_JOIN     = 'right join';
+    const FULL_JOIN      = 'full join';
+    const CROSS_JOIN     = 'cross join';
+    const NATURAL_JOIN   = 'natural join';
+
+    const SQL_WILDCARD   = '*';
+    const SQL_SELECT     = 'SELECT';
+    const SQL_UNION      = 'UNION';
+    const SQL_UNION_ALL  = 'UNION ALL';
+    const SQL_FROM       = 'FROM';
+    const SQL_WHERE      = 'WHERE';
+    const SQL_DISTINCT   = 'DISTINCT';
+    const SQL_GROUP_BY   = 'GROUP BY';
+    const SQL_ORDER_BY   = 'ORDER BY';
+    const SQL_HAVING     = 'HAVING';
+    const SQL_FOR_UPDATE = 'FOR UPDATE';
+    const SQL_AND        = 'AND';
+    const SQL_AS         = 'AS';
+    const SQL_OR         = 'OR';
+    const SQL_ON         = 'ON';
+    const SQL_ASC        = 'ASC';
+    const SQL_DESC       = 'DESC';
+
+    /**
+     * Bind variables for query
+     *
+     * @var array
+     */
+    protected $_bind = array();
+
+    /**
+     * Zend_Db_Adapter_Abstract object.
+     *
+     * @var Zend_Db_Adapter_Abstract
+     */
+    protected $_adapter;
+
+    /**
+     * The initial values for the $_parts array.
+     * NOTE: It is important for the 'FOR_UPDATE' part to be last to ensure
+     * meximum compatibility with database adapters.
+     *
+     * @var array
+     */
+    protected static $_partsInit = array(
+        self::DISTINCT     => false,
+        self::COLUMNS      => array(),
+        self::UNION        => array(),
+        self::FROM         => array(),
+        self::WHERE        => array(),
+        self::GROUP        => array(),
+        self::HAVING       => array(),
+        self::ORDER        => array(),
+        self::LIMIT_COUNT  => null,
+        self::LIMIT_OFFSET => null,
+        self::FOR_UPDATE   => false
+    );
+
+    /**
+     * Specify legal join types.
+     *
+     * @var array
+     */
+    protected static $_joinTypes = array(
+        self::INNER_JOIN,
+        self::LEFT_JOIN,
+        self::RIGHT_JOIN,
+        self::FULL_JOIN,
+        self::CROSS_JOIN,
+        self::NATURAL_JOIN,
+    );
+
+    /**
+     * Specify legal union types.
+     *
+     * @var array
+     */
+    protected static $_unionTypes = array(
+        self::SQL_UNION,
+        self::SQL_UNION_ALL
+    );
+
+    /**
+     * The component parts of a SELECT statement.
+     * Initialized to the $_partsInit array in the constructor.
+     *
+     * @var array
+     */
+    protected $_parts = array();
+
+    /**
+     * Tracks which columns are being select from each table and join.
+     *
+     * @var array
+     */
+    protected $_tableCols = array();
+
+    /**
+     * Class constructor
+     *
+     * @param Zend_Db_Adapter_Abstract $adapter
+     */
+    public function __construct(Zend_Db_Adapter_Abstract $adapter)
+    {
+        $this->_adapter = $adapter;
+        $this->_parts = self::$_partsInit;
+    }
+
+    /**
+     * Get bind variables
+     *
+     * @return array
+     */
+    public function getBind()
+    {
+        return $this->_bind;
+    }
+
+    /**
+     * Set bind variables
+     *
+     * @param mixed $bind
+     * @return Zend_Db_Select
+     */
+    public function bind($bind)
+    {
+        $this->_bind = $bind;
+
+        return $this;
+    }
+
+    /**
+     * Makes the query SELECT DISTINCT.
+     *
+     * @param bool $flag Whether or not the SELECT is DISTINCT (default true).
+     * @return Zend_Db_Select This Zend_Db_Select object.
+     */
+    public function distinct($flag = true)
+    {
+        $this->_parts[self::DISTINCT] = (bool) $flag;
+        return $this;
+    }
+
+    /**
+     * Adds a FROM table and optional columns to the query.
+     *
+     * The first parameter $name can be a simple string, in which case the
+     * correlation name is generated automatically.  If you want to specify
+     * the correlation name, the first parameter must be an associative
+     * array in which the key is the physical table name, and the value is
+     * the correlation name.  For example, array('table' => 'alias').
+     * The correlation name is prepended to all columns fetched for this
+     * table.
+     *
+     * The second parameter can be a single string or Zend_Db_Expr object,
+     * or else an array of strings or Zend_Db_Expr objects.
+     *
+     * The first parameter can be null or an empty string, in which case
+     * no correlation name is generated or prepended to the columns named
+     * in the second parameter.
+     *
+     * @param  array|string|Zend_Db_Expr $name The table name or an associative array relating table name to
+     *                                         correlation name.
+     * @param  array|string|Zend_Db_Expr $cols The columns to select from this table.
+     * @param  string $schema The schema name to specify, if any.
+     * @return Zend_Db_Select This Zend_Db_Select object.
+     */
+    public function from($name, $cols = '*', $schema = null)
+    {
+        return $this->_join(self::FROM, $name, null, $cols, $schema);
+    }
+
+    /**
+     * Specifies the columns used in the FROM clause.
+     *
+     * The parameter can be a single string or Zend_Db_Expr object,
+     * or else an array of strings or Zend_Db_Expr objects.
+     *
+     * @param  array|string|Zend_Db_Expr $cols The columns to select from this table.
+     * @param  string $correlationName Correlation name of target table. OPTIONAL
+     * @return Zend_Db_Select This Zend_Db_Select object.
+     */
+    public function columns($cols = '*', $correlationName = null)
+    {
+        if ($correlationName === null && count($this->_parts[self::FROM])) {
+            $correlationNameKeys = array_keys($this->_parts[self::FROM]);
+            $correlationName = current($correlationNameKeys);
+        }
+
+        if (!array_key_exists($correlationName, $this->_parts[self::FROM])) {
+            /**
+             * @see Zend_Db_Select_Exception
+             */
+            require_once 'Zend/Db/Select/Exception.php';
+            throw new Zend_Db_Select_Exception("No table has been specified for the FROM clause");
+        }
+
+        $this->_tableCols($correlationName, $cols);
+
+        return $this;
+    }
+
+    /**
+     * Adds a UNION clause to the query.
+     *
+     * The first parameter has to be an array of Zend_Db_Select or
+     * sql query strings.
+     *
+     * <code>
+     * $sql1 = $db->select();
+     * $sql2 = "SELECT ...";
+     * $select = $db->select()
+     *      ->union(array($sql1, $sql2))
+     *      ->order("id");
+     * </code>
+     *
+     * @param  array $select Array of select clauses for the union.
+     * @return Zend_Db_Select This Zend_Db_Select object.
+     */
+    public function union($select = array(), $type = self::SQL_UNION)
+    {
+        if (!is_array($select)) {
+            require_once 'Zend/Db/Select/Exception.php';
+            throw new Zend_Db_Select_Exception(
+                "union() only accepts an array of Zend_Db_Select instances of sql query strings."
+            );
+        }
+
+        if (!in_array($type, self::$_unionTypes)) {
+            require_once 'Zend/Db/Select/Exception.php';
+            throw new Zend_Db_Select_Exception("Invalid union type '{$type}'");
+        }
+
+        foreach ($select as $target) {
+            $this->_parts[self::UNION][] = array($target, $type);
+        }
+
+        return $this;
+    }
+
+    /**
+     * Adds a JOIN table and columns to the query.
+     *
+     * The $name and $cols parameters follow the same logic
+     * as described in the from() method.
+     *
+     * @param  array|string|Zend_Db_Expr $name The table name.
+     * @param  string $cond Join on this condition.
+     * @param  array|string $cols The columns to select from the joined table.
+     * @param  string $schema The database name to specify, if any.
+     * @return Zend_Db_Select This Zend_Db_Select object.
+     */
+    public function join($name, $cond, $cols = self::SQL_WILDCARD, $schema = null)
+    {
+        return $this->joinInner($name, $cond, $cols, $schema);
+    }
+
+    /**
+     * Add an INNER JOIN table and colums to the query
+     * Rows in both tables are matched according to the expression
+     * in the $cond argument.  The result set is comprised
+     * of all cases where rows from the left table match
+     * rows from the right table.
+     *
+     * The $name and $cols parameters follow the same logic
+     * as described in the from() method.
+     *
+     * @param  array|string|Zend_Db_Expr $name The table name.
+     * @param  string $cond Join on this condition.
+     * @param  array|string $cols The columns to select from the joined table.
+     * @param  string $schema The database name to specify, if any.
+     * @return Zend_Db_Select This Zend_Db_Select object.
+     */
+    public function joinInner($name, $cond, $cols = self::SQL_WILDCARD, $schema = null)
+    {
+        return $this->_join(self::INNER_JOIN, $name, $cond, $cols, $schema);
+    }
+
+    /**
+     * Add a LEFT OUTER JOIN table and colums to the query
+     * All rows from the left operand table are included,
+     * matching rows from the right operand table included,
+     * and the columns from the right operand table are filled
+     * with NULLs if no row exists matching the left table.
+     *
+     * The $name and $cols parameters follow the same logic
+     * as described in the from() method.
+     *
+     * @param  array|string|Zend_Db_Expr $name The table name.
+     * @param  string $cond Join on this condition.
+     * @param  array|string $cols The columns to select from the joined table.
+     * @param  string $schema The database name to specify, if any.
+     * @return Zend_Db_Select This Zend_Db_Select object.
+     */
+    public function joinLeft($name, $cond, $cols = self::SQL_WILDCARD, $schema = null)
+    {
+        return $this->_join(self::LEFT_JOIN, $name, $cond, $cols, $schema);
+    }
+
+    /**
+     * Add a RIGHT OUTER JOIN table and colums to the query.
+     * Right outer join is the complement of left outer join.
+     * All rows from the right operand table are included,
+     * matching rows from the left operand table included,
+     * and the columns from the left operand table are filled
+     * with NULLs if no row exists matching the right table.
+     *
+     * The $name and $cols parameters follow the same logic
+     * as described in the from() method.
+     *
+     * @param  array|string|Zend_Db_Expr $name The table name.
+     * @param  string $cond Join on this condition.
+     * @param  array|string $cols The columns to select from the joined table.
+     * @param  string $schema The database name to specify, if any.
+     * @return Zend_Db_Select This Zend_Db_Select object.
+     */
+    public function joinRight($name, $cond, $cols = self::SQL_WILDCARD, $schema = null)
+    {
+        return $this->_join(self::RIGHT_JOIN, $name, $cond, $cols, $schema);
+    }
+
+    /**
+     * Add a FULL OUTER JOIN table and colums to the query.
+     * A full outer join is like combining a left outer join
+     * and a right outer join.  All rows from both tables are
+     * included, paired with each other on the same row of the
+     * result set if they satisfy the join condition, and otherwise
+     * paired with NULLs in place of columns from the other table.
+     *
+     * The $name and $cols parameters follow the same logic
+     * as described in the from() method.
+     *
+     * @param  array|string|Zend_Db_Expr $name The table name.
+     * @param  string $cond Join on this condition.
+     * @param  array|string $cols The columns to select from the joined table.
+     * @param  string $schema The database name to specify, if any.
+     * @return Zend_Db_Select This Zend_Db_Select object.
+     */
+    public function joinFull($name, $cond, $cols = self::SQL_WILDCARD, $schema = null)
+    {
+        return $this->_join(self::FULL_JOIN, $name, $cond, $cols, $schema);
+    }
+
+    /**
+     * Add a CROSS JOIN table and colums to the query.
+     * A cross join is a cartesian product; there is no join condition.
+     *
+     * The $name and $cols parameters follow the same logic
+     * as described in the from() method.
+     *
+     * @param  array|string|Zend_Db_Expr $name The table name.
+     * @param  array|string $cols The columns to select from the joined table.
+     * @param  string $schema The database name to specify, if any.
+     * @return Zend_Db_Select This Zend_Db_Select object.
+     */
+    public function joinCross($name, $cols = self::SQL_WILDCARD, $schema = null)
+    {
+        return $this->_join(self::CROSS_JOIN, $name, null, $cols, $schema);
+    }
+
+    /**
+     * Add a NATURAL JOIN table and colums to the query.
+     * A natural join assumes an equi-join across any column(s)
+     * that appear with the same name in both tables.
+     * Only natural inner joins are supported by this API,
+     * even though SQL permits natural outer joins as well.
+     *
+     * The $name and $cols parameters follow the same logic
+     * as described in the from() method.
+     *
+     * @param  array|string|Zend_Db_Expr $name The table name.
+     * @param  array|string $cols The columns to select from the joined table.
+     * @param  string $schema The database name to specify, if any.
+     * @return Zend_Db_Select This Zend_Db_Select object.
+     */
+    public function joinNatural($name, $cols = self::SQL_WILDCARD, $schema = null)
+    {
+        return $this->_join(self::NATURAL_JOIN, $name, null, $cols, $schema);
+    }
+
+    /**
+     * Adds a WHERE condition to the query by AND.
+     *
+     * If a value is passed as the second param, it will be quoted
+     * and replaced into the condition wherever a question-mark
+     * appears. Array values are quoted and comma-separated.
+     *
+     * <code>
+     * // simplest but non-secure
+     * $select->where("id = $id");
+     *
+     * // secure (ID is quoted but matched anyway)
+     * $select->where('id = ?', $id);
+     *
+     * // alternatively, with named binding
+     * $select->where('id = :id');
+     * </code>
+     *
+     * Note that it is more correct to use named bindings in your
+     * queries for values other than strings. When you use named
+     * bindings, don't forget to pass the values when actually
+     * making a query:
+     *
+     * <code>
+     * $db->fetchAll($select, array('id' => 5));
+     * </code>
+     *
+     * @param string   $cond  The WHERE condition.
+     * @param mixed    $value OPTIONAL The value to quote into the condition.
+     * @param int      $type  OPTIONAL The type of the given value
+     * @return Zend_Db_Select This Zend_Db_Select object.
+     */
+    public function where($cond, $value = null, $type = null)
+    {
+        $this->_parts[self::WHERE][] = $this->_where($cond, $value, $type, true);
+
+        return $this;
+    }
+
+    /**
+     * Adds a WHERE condition to the query by OR.
+     *
+     * Otherwise identical to where().
+     *
+     * @param string   $cond  The WHERE condition.
+     * @param mixed    $value OPTIONAL The value to quote into the condition.
+     * @param int      $type  OPTIONAL The type of the given value
+     * @return Zend_Db_Select This Zend_Db_Select object.
+     *
+     * @see where()
+     */
+    public function orWhere($cond, $value = null, $type = null)
+    {
+        $this->_parts[self::WHERE][] = $this->_where($cond, $value, $type, false);
+
+        return $this;
+    }
+
+    /**
+     * Adds grouping to the query.
+     *
+     * @param  array|string $spec The column(s) to group by.
+     * @return Zend_Db_Select This Zend_Db_Select object.
+     */
+    public function group($spec)
+    {
+        if (!is_array($spec)) {
+            $spec = array($spec);
+        }
+
+        foreach ($spec as $val) {
+            if (preg_match('/\(.*\)/', (string) $val)) {
+                $val = new Zend_Db_Expr($val);
+            }
+            $this->_parts[self::GROUP][] = $val;
+        }
+
+        return $this;
+    }
+
+    /**
+     * Adds a HAVING condition to the query by AND.
+     *
+     * If a value is passed as the second param, it will be quoted
+     * and replaced into the condition wherever a question-mark
+     * appears. See {@link where()} for an example
+     *
+     * @param string $cond The HAVING condition.
+     * @param mixed    $value OPTIONAL The value to quote into the condition.
+     * @param int      $type  OPTIONAL The type of the given value
+     * @return Zend_Db_Select This Zend_Db_Select object.
+     */
+    public function having($cond, $value = null, $type = null)
+    {
+        if ($value !== null) {
+            $cond = $this->_adapter->quoteInto($cond, $value, $type);
+        }
+
+        if ($this->_parts[self::HAVING]) {
+            $this->_parts[self::HAVING][] = self::SQL_AND . " ($cond)";
+        } else {
+            $this->_parts[self::HAVING][] = "($cond)";
+        }
+
+        return $this;
+    }
+
+    /**
+     * Adds a HAVING condition to the query by OR.
+     *
+     * Otherwise identical to orHaving().
+     *
+     * @param string $cond The HAVING condition.
+     * @param mixed    $value OPTIONAL The value to quote into the condition.
+     * @param int      $type  OPTIONAL The type of the given value
+     * @return Zend_Db_Select This Zend_Db_Select object.
+     *
+     * @see having()
+     */
+    public function orHaving($cond, $value = null, $type = null)
+    {
+        if ($value !== null) {
+            $cond = $this->_adapter->quoteInto($cond, $value, $type);
+        }
+
+        if ($this->_parts[self::HAVING]) {
+            $this->_parts[self::HAVING][] = self::SQL_OR . " ($cond)";
+        } else {
+            $this->_parts[self::HAVING][] = "($cond)";
+        }
+
+        return $this;
+    }
+
+    /**
+     * Adds a row order to the query.
+     *
+     * @param mixed $spec The column(s) and direction to order by.
+     * @return Zend_Db_Select This Zend_Db_Select object.
+     */
+    public function order($spec)
+    {
+        if (!is_array($spec)) {
+            $spec = array($spec);
+        }
+
+        // force 'ASC' or 'DESC' on each order spec, default is ASC.
+        foreach ($spec as $val) {
+            if ($val instanceof Zend_Db_Expr) {
+                $expr = $val->__toString();
+                if (empty($expr)) {
+                    continue;
+                }
+                $this->_parts[self::ORDER][] = $val;
+            } else {
+                if (empty($val)) {
+                    continue;
+                }
+                $direction = self::SQL_ASC;
+                if (preg_match('/(.*\W)(' . self::SQL_ASC . '|' . self::SQL_DESC . ')\b/si', $val, $matches)) {
+                    $val = trim($matches[1]);
+                    $direction = $matches[2];
+                }
+                if (preg_match('/\(.*\)/', $val)) {
+                    $val = new Zend_Db_Expr($val);
+                }
+                $this->_parts[self::ORDER][] = array($val, $direction);
+            }
+        }
+
+        return $this;
+    }
+
+    /**
+     * Sets a limit count and offset to the query.
+     *
+     * @param int $count OPTIONAL The number of rows to return.
+     * @param int $offset OPTIONAL Start returning after this many rows.
+     * @return Zend_Db_Select This Zend_Db_Select object.
+     */
+    public function limit($count = null, $offset = null)
+    {
+        $this->_parts[self::LIMIT_COUNT]  = (int) $count;
+        $this->_parts[self::LIMIT_OFFSET] = (int) $offset;
+        return $this;
+    }
+
+    /**
+     * Sets the limit and count by page number.
+     *
+     * @param int $page Limit results to this page number.
+     * @param int $rowCount Use this many rows per page.
+     * @return Zend_Db_Select This Zend_Db_Select object.
+     */
+    public function limitPage($page, $rowCount)
+    {
+        $page     = ($page > 0)     ? $page     : 1;
+        $rowCount = ($rowCount > 0) ? $rowCount : 1;
+        $this->_parts[self::LIMIT_COUNT]  = (int) $rowCount;
+        $this->_parts[self::LIMIT_OFFSET] = (int) $rowCount * ($page - 1);
+        return $this;
+    }
+
+    /**
+     * Makes the query SELECT FOR UPDATE.
+     *
+     * @param bool $flag Whether or not the SELECT is FOR UPDATE (default true).
+     * @return Zend_Db_Select This Zend_Db_Select object.
+     */
+    public function forUpdate($flag = true)
+    {
+        $this->_parts[self::FOR_UPDATE] = (bool) $flag;
+        return $this;
+    }
+
+    /**
+     * Get part of the structured information for the currect query.
+     *
+     * @param string $part
+     * @return mixed
+     * @throws Zend_Db_Select_Exception
+     */
+    public function getPart($part)
+    {
+        $part = strtolower($part);
+        if (!array_key_exists($part, $this->_parts)) {
+            require_once 'Zend/Db/Select/Exception.php';
+            throw new Zend_Db_Select_Exception("Invalid Select part '$part'");
+        }
+        return $this->_parts[$part];
+    }
+
+    /**
+     * Executes the current select object and returns the result
+     *
+     * @param integer $fetchMode OPTIONAL
+     * @param  mixed  $bind An array of data to bind to the placeholders.
+     * @return PDO_Statement|Zend_Db_Statement
+     */
+    public function query($fetchMode = null, $bind = array())
+    {
+        if (!empty($bind)) {
+            $this->bind($bind);
+        }
+
+        $stmt = $this->_adapter->query($this);
+        if ($fetchMode == null) {
+            $fetchMode = $this->_adapter->getFetchMode();
+        }
+        $stmt->setFetchMode($fetchMode);
+        return $stmt;
+    }
+
+    /**
+     * Converts this object to an SQL SELECT string.
+     *
+     * @return string|null This object as a SELECT string. (or null if a string cannot be produced.)
+     */
+    public function assemble()
+    {
+        $sql = self::SQL_SELECT;
+        foreach (array_keys(self::$_partsInit) as $part) {
+            $method = '_render' . ucfirst($part);
+            if (method_exists($this, $method)) {
+                $sql = $this->$method($sql);
+            }
+        }
+        return $sql;
+    }
+
+    /**
+     * Clear parts of the Select object, or an individual part.
+     *
+     * @param string $part OPTIONAL
+     * @return Zend_Db_Select
+     */
+    public function reset($part = null)
+    {
+        if ($part == null) {
+            $this->_parts = self::$_partsInit;
+        } else if (array_key_exists($part, self::$_partsInit)) {
+            $this->_parts[$part] = self::$_partsInit[$part];
+        }
+        return $this;
+    }
+
+    /**
+     * Gets the Zend_Db_Adapter_Abstract for this
+     * particular Zend_Db_Select object.
+     *
+     * @return Zend_Db_Adapter_Abstract
+     */
+    public function getAdapter()
+    {
+        return $this->_adapter;
+    }
+
+    /**
+     * Populate the {@link $_parts} 'join' key
+     *
+     * Does the dirty work of populating the join key.
+     *
+     * The $name and $cols parameters follow the same logic
+     * as described in the from() method.
+     *
+     * @param  null|string $type Type of join; inner, left, and null are currently supported
+     * @param  array|string|Zend_Db_Expr $name Table name
+     * @param  string $cond Join on this condition
+     * @param  array|string $cols The columns to select from the joined table
+     * @param  string $schema The database name to specify, if any.
+     * @return Zend_Db_Select This Zend_Db_Select object
+     * @throws Zend_Db_Select_Exception
+     */
+    protected function _join($type, $name, $cond, $cols, $schema = null)
+    {
+        if (!in_array($type, self::$_joinTypes) && $type != self::FROM) {
+            /**
+             * @see Zend_Db_Select_Exception
+             */
+            require_once 'Zend/Db/Select/Exception.php';
+            throw new Zend_Db_Select_Exception("Invalid join type '$type'");
+        }
+
+        if (count($this->_parts[self::UNION])) {
+            require_once 'Zend/Db/Select/Exception.php';
+            throw new Zend_Db_Select_Exception("Invalid use of table with " . self::SQL_UNION);
+        }
+
+        if (empty($name)) {
+            $correlationName = $tableName = '';
+        } else if (is_array($name)) {
+            // Must be array($correlationName => $tableName) or array($ident, ...)
+            foreach ($name as $_correlationName => $_tableName) {
+                if (is_string($_correlationName)) {
+                    // We assume the key is the correlation name and value is the table name
+                    $tableName = $_tableName;
+                    $correlationName = $_correlationName;
+                } else {
+                    // We assume just an array of identifiers, with no correlation name
+                    $tableName = $_tableName;
+                    $correlationName = $this->_uniqueCorrelation($tableName);
+                }
+                break;
+            }
+        } else if ($name instanceof Zend_Db_Expr|| $name instanceof Zend_Db_Select) {
+            $tableName = $name;
+            $correlationName = $this->_uniqueCorrelation('t');
+        } else if (preg_match('/^(.+)\s+AS\s+(.+)$/i', $name, $m)) {
+            $tableName = $m[1];
+            $correlationName = $m[2];
+        } else {
+            $tableName = $name;
+            $correlationName = $this->_uniqueCorrelation($tableName);
+        }
+
+        // Schema from table name overrides schema argument
+        if (!is_object($tableName) && false !== strpos($tableName, '.')) {
+            list($schema, $tableName) = explode('.', $tableName);
+        }
+
+        $lastFromCorrelationName = null;
+        if (!empty($correlationName)) {
+            if (array_key_exists($correlationName, $this->_parts[self::FROM])) {
+                /**
+                 * @see Zend_Db_Select_Exception
+                 */
+                require_once 'Zend/Db/Select/Exception.php';
+                throw new Zend_Db_Select_Exception("You cannot define a correlation name '$correlationName' more than once");
+            }
+
+            if ($type == self::FROM) {
+                // append this from after the last from joinType
+                $tmpFromParts = $this->_parts[self::FROM];
+                $this->_parts[self::FROM] = array();
+                // move all the froms onto the stack
+                while ($tmpFromParts) {
+                    $currentCorrelationName = key($tmpFromParts);
+                    if ($tmpFromParts[$currentCorrelationName]['joinType'] != self::FROM) {
+                        break;
+                    }
+                    $lastFromCorrelationName = $currentCorrelationName;
+                    $this->_parts[self::FROM][$currentCorrelationName] = array_shift($tmpFromParts);
+                }
+            } else {
+                $tmpFromParts = array();
+            }
+            $this->_parts[self::FROM][$correlationName] = array(
+                'joinType'      => $type,
+                'schema'        => $schema,
+                'tableName'     => $tableName,
+                'joinCondition' => $cond
+                );
+            while ($tmpFromParts) {
+                $currentCorrelationName = key($tmpFromParts);
+                $this->_parts[self::FROM][$currentCorrelationName] = array_shift($tmpFromParts);
+            }
+        }
+
+        // add to the columns from this joined table
+        if ($type == self::FROM && $lastFromCorrelationName == null) {
+            $lastFromCorrelationName = true;
+        }
+        $this->_tableCols($correlationName, $cols, $lastFromCorrelationName);
+
+        return $this;
+    }
+
+    /**
+     * Handle JOIN... USING... syntax
+     *
+     * This is functionality identical to the existing JOIN methods, however
+     * the join condition can be passed as a single column name. This method
+     * then completes the ON condition by using the same field for the FROM
+     * table and the JOIN table.
+     *
+     * <code>
+     * $select = $db->select()->from('table1')
+     *                        ->joinUsing('table2', 'column1');
+     *
+     * // SELECT * FROM table1 JOIN table2 ON table1.column1 = table2.column2
+     * </code>
+     *
+     * These joins are called by the developer simply by adding 'Using' to the
+     * method name. E.g.
+     * * joinUsing
+     * * joinInnerUsing
+     * * joinFullUsing
+     * * joinRightUsing
+     * * joinLeftUsing
+     *
+     * @return Zend_Db_Select This Zend_Db_Select object.
+     */
+    public function _joinUsing($type, $name, $cond, $cols = '*', $schema = null)
+    {
+        if (empty($this->_parts[self::FROM])) {
+            require_once 'Zend/Db/Select/Exception.php';
+            throw new Zend_Db_Select_Exception("You can only perform a joinUsing after specifying a FROM table");
+        }
+
+        $join  = $this->_adapter->quoteIdentifier(key($this->_parts[self::FROM]), true);
+        $from  = $this->_adapter->quoteIdentifier($this->_uniqueCorrelation($name), true);
+
+        $cond1 = $from . '.' . $cond;
+        $cond2 = $join . '.' . $cond;
+        $cond  = $cond1 . ' = ' . $cond2;
+
+        return $this->_join($type, $name, $cond, $cols, $schema);
+    }
+
+    /**
+     * Generate a unique correlation name
+     *
+     * @param string|array $name A qualified identifier.
+     * @return string A unique correlation name.
+     */
+    private function _uniqueCorrelation($name)
+    {
+        if (is_array($name)) {
+            $c = end($name);
+        } else {
+            // Extract just the last name of a qualified table name
+            $dot = strrpos($name,'.');
+            $c = ($dot === false) ? $name : substr($name, $dot+1);
+        }
+        for ($i = 2; array_key_exists($c, $this->_parts[self::FROM]); ++$i) {
+            $c = $name . '_' . (string) $i;
+        }
+        return $c;
+    }
+
+    /**
+     * Adds to the internal table-to-column mapping array.
+     *
+     * @param  string $tbl The table/join the columns come from.
+     * @param  array|string $cols The list of columns; preferably as
+     * an array, but possibly as a string containing one column.
+     * @param  bool|string True if it should be prepended, a correlation name if it should be inserted
+     * @return void
+     */
+    protected function _tableCols($correlationName, $cols, $afterCorrelationName = null)
+    {
+        if (!is_array($cols)) {
+            $cols = array($cols);
+        }
+
+        if ($correlationName == null) {
+            $correlationName = '';
+        }
+
+        $columnValues = array();
+
+        foreach (array_filter($cols) as $alias => $col) {
+            $currentCorrelationName = $correlationName;
+            if (is_string($col)) {
+                // Check for a column matching "<column> AS <alias>" and extract the alias name
+                if (preg_match('/^(.+)\s+' . self::SQL_AS . '\s+(.+)$/i', $col, $m)) {
+                    $col = $m[1];
+                    $alias = $m[2];
+                }
+                // Check for columns that look like functions and convert to Zend_Db_Expr
+                if (preg_match('/\(.*\)/', $col)) {
+                    $col = new Zend_Db_Expr($col);
+                } elseif (preg_match('/(.+)\.(.+)/', $col, $m)) {
+                    $currentCorrelationName = $m[1];
+                    $col = $m[2];
+                }
+            }
+            $columnValues[] = array($currentCorrelationName, $col, is_string($alias) ? $alias : null);
+        }
+
+        if ($columnValues) {
+
+            // should we attempt to prepend or insert these values?
+            if ($afterCorrelationName === true || is_string($afterCorrelationName)) {
+                $tmpColumns = $this->_parts[self::COLUMNS];
+                $this->_parts[self::COLUMNS] = array();
+            } else {
+                $tmpColumns = array();
+            }
+
+            // find the correlation name to insert after
+            if (is_string($afterCorrelationName)) {
+                while ($tmpColumns) {
+                    $this->_parts[self::COLUMNS][] = $currentColumn = array_shift($tmpColumns);
+                    if ($currentColumn[0] == $afterCorrelationName) {
+                        break;
+                    }
+                }
+            }
+
+            // apply current values to current stack
+            foreach ($columnValues as $columnValue) {
+                array_push($this->_parts[self::COLUMNS], $columnValue);
+            }
+
+            // finish ensuring that all previous values are applied (if they exist)
+            while ($tmpColumns) {
+                array_push($this->_parts[self::COLUMNS], array_shift($tmpColumns));
+            }
+        }
+    }
+
+    /**
+     * Internal function for creating the where clause
+     *
+     * @param string   $condition
+     * @param mixed    $value  optional
+     * @param string   $type   optional
+     * @param boolean  $bool  true = AND, false = OR
+     * @return string  clause
+     */
+    protected function _where($condition, $value = null, $type = null, $bool = true)
+    {
+        if (count($this->_parts[self::UNION])) {
+            require_once 'Zend/Db/Select/Exception.php';
+            throw new Zend_Db_Select_Exception("Invalid use of where clause with " . self::SQL_UNION);
+        }
+
+        if ($value !== null) {
+            $condition = $this->_adapter->quoteInto($condition, $value, $type);
+        }
+
+        $cond = "";
+        if ($this->_parts[self::WHERE]) {
+            if ($bool === true) {
+                $cond = self::SQL_AND . ' ';
+            } else {
+                $cond = self::SQL_OR . ' ';
+            }
+        }
+
+        return $cond . "($condition)";
+    }
+
+    /**
+     * @return array
+     */
+    protected function _getDummyTable()
+    {
+        return array();
+    }
+
+    /**
+     * Return a quoted schema name
+     *
+     * @param string   $schema  The schema name OPTIONAL
+     * @return string|null
+     */
+    protected function _getQuotedSchema($schema = null)
+    {
+        if ($schema === null) {
+            return null;
+        }
+        return $this->_adapter->quoteIdentifier($schema, true) . '.';
+    }
+
+    /**
+     * Return a quoted table name
+     *
+     * @param string   $tableName        The table name
+     * @param string   $correlationName  The correlation name OPTIONAL
+     * @return string
+     */
+    protected function _getQuotedTable($tableName, $correlationName = null)
+    {
+        return $this->_adapter->quoteTableAs($tableName, $correlationName, true);
+    }
+
+    /**
+     * Render DISTINCT clause
+     *
+     * @param string   $sql SQL query
+     * @return string
+     */
+    protected function _renderDistinct($sql)
+    {
+        if ($this->_parts[self::DISTINCT]) {
+            $sql .= ' ' . self::SQL_DISTINCT;
+        }
+
+        return $sql;
+    }
+
+    /**
+     * Render DISTINCT clause
+     *
+     * @param string   $sql SQL query
+     * @return string|null
+     */
+    protected function _renderColumns($sql)
+    {
+        if (!count($this->_parts[self::COLUMNS])) {
+            return null;
+        }
+
+        $columns = array();
+        foreach ($this->_parts[self::COLUMNS] as $columnEntry) {
+            list($correlationName, $column, $alias) = $columnEntry;
+            if ($column instanceof Zend_Db_Expr) {
+                $columns[] = $this->_adapter->quoteColumnAs($column, $alias, true);
+            } else {
+                if ($column == self::SQL_WILDCARD) {
+                    $column = new Zend_Db_Expr(self::SQL_WILDCARD);
+                    $alias = null;
+                }
+                if (empty($correlationName)) {
+                    $columns[] = $this->_adapter->quoteColumnAs($column, $alias, true);
+                } else {
+                    $columns[] = $this->_adapter->quoteColumnAs(array($correlationName, $column), $alias, true);
+                }
+            }
+        }
+
+        return $sql .= ' ' . implode(', ', $columns);
+    }
+
+    /**
+     * Render FROM clause
+     *
+     * @param string   $sql SQL query
+     * @return string
+     */
+    protected function _renderFrom($sql)
+    {
+        /*
+         * If no table specified, use RDBMS-dependent solution
+         * for table-less query.  e.g. DUAL in Oracle.
+         */
+        if (empty($this->_parts[self::FROM])) {
+            $this->_parts[self::FROM] = $this->_getDummyTable();
+        }
+
+        $from = array();
+
+        foreach ($this->_parts[self::FROM] as $correlationName => $table) {
+            $tmp = '';
+
+            $joinType = ($table['joinType'] == self::FROM) ? self::INNER_JOIN : $table['joinType'];
+
+            // Add join clause (if applicable)
+            if (! empty($from)) {
+                $tmp .= ' ' . strtoupper($joinType) . ' ';
+            }
+
+            $tmp .= $this->_getQuotedSchema($table['schema']);
+            $tmp .= $this->_getQuotedTable($table['tableName'], $correlationName);
+
+            // Add join conditions (if applicable)
+            if (!empty($from) && ! empty($table['joinCondition'])) {
+                $tmp .= ' ' . self::SQL_ON . ' ' . $table['joinCondition'];
+            }
+
+            // Add the table name and condition add to the list
+            $from[] = $tmp;
+        }
+
+        // Add the list of all joins
+        if (!empty($from)) {
+            $sql .= ' ' . self::SQL_FROM . ' ' . implode("\n", $from);
+        }
+
+        return $sql;
+    }
+
+    /**
+     * Render UNION query
+     *
+     * @param string   $sql SQL query
+     * @return string
+     */
+    protected function _renderUnion($sql)
+    {
+        if ($this->_parts[self::UNION]) {
+            $parts = count($this->_parts[self::UNION]);
+            foreach ($this->_parts[self::UNION] as $cnt => $union) {
+                list($target, $type) = $union;
+                if ($target instanceof Zend_Db_Select) {
+                    $target = $target->assemble();
+                }
+                $sql .= $target;
+                if ($cnt < $parts - 1) {
+                    $sql .= ' ' . $type . ' ';
+                }
+            }
+        }
+
+        return $sql;
+    }
+
+    /**
+     * Render WHERE clause
+     *
+     * @param string   $sql SQL query
+     * @return string
+     */
+    protected function _renderWhere($sql)
+    {
+        if ($this->_parts[self::FROM] && $this->_parts[self::WHERE]) {
+            $sql .= ' ' . self::SQL_WHERE . ' ' .  implode(' ', $this->_parts[self::WHERE]);
+        }
+
+        return $sql;
+    }
+
+    /**
+     * Render GROUP clause
+     *
+     * @param string   $sql SQL query
+     * @return string
+     */
+    protected function _renderGroup($sql)
+    {
+        if ($this->_parts[self::FROM] && $this->_parts[self::GROUP]) {
+            $group = array();
+            foreach ($this->_parts[self::GROUP] as $term) {
+                $group[] = $this->_adapter->quoteIdentifier($term, true);
+            }
+            $sql .= ' ' . self::SQL_GROUP_BY . ' ' . implode(",\n\t", $group);
+        }
+
+        return $sql;
+    }
+
+    /**
+     * Render HAVING clause
+     *
+     * @param string   $sql SQL query
+     * @return string
+     */
+    protected function _renderHaving($sql)
+    {
+        if ($this->_parts[self::FROM] && $this->_parts[self::HAVING]) {
+            $sql .= ' ' . self::SQL_HAVING . ' ' . implode(' ', $this->_parts[self::HAVING]);
+        }
+
+        return $sql;
+    }
+
+    /**
+     * Render ORDER clause
+     *
+     * @param string   $sql SQL query
+     * @return string
+     */
+    protected function _renderOrder($sql)
+    {
+        if ($this->_parts[self::ORDER]) {
+            $order = array();
+            foreach ($this->_parts[self::ORDER] as $term) {
+                if (is_array($term)) {
+                    if(is_numeric($term[0]) && strval(intval($term[0])) == $term[0]) {
+                        $order[] = (int)trim($term[0]) . ' ' . $term[1];
+                    } else {
+                        $order[] = $this->_adapter->quoteIdentifier($term[0], true) . ' ' . $term[1];
+                    }
+                } else if (is_numeric($term) && strval(intval($term)) == $term) {
+                    $order[] = (int)trim($term);
+                } else {
+                    $order[] = $this->_adapter->quoteIdentifier($term, true);
+                }
+            }
+            $sql .= ' ' . self::SQL_ORDER_BY . ' ' . implode(', ', $order);
+        }
+
+        return $sql;
+    }
+
+    /**
+     * Render LIMIT OFFSET clause
+     *
+     * @param string   $sql SQL query
+     * @return string
+     */
+    protected function _renderLimitoffset($sql)
+    {
+        $count = 0;
+        $offset = 0;
+
+        if (!empty($this->_parts[self::LIMIT_OFFSET])) {
+            $offset = (int) $this->_parts[self::LIMIT_OFFSET];
+            $count = PHP_INT_MAX;
+        }
+
+        if (!empty($this->_parts[self::LIMIT_COUNT])) {
+            $count = (int) $this->_parts[self::LIMIT_COUNT];
+        }
+
+        /*
+         * Add limits clause
+         */
+        if ($count > 0) {
+            $sql = trim($this->_adapter->limit($sql, $count, $offset));
+        }
+
+        return $sql;
+    }
+
+    /**
+     * Render FOR UPDATE clause
+     *
+     * @param string   $sql SQL query
+     * @return string
+     */
+    protected function _renderForupdate($sql)
+    {
+        if ($this->_parts[self::FOR_UPDATE]) {
+            $sql .= ' ' . self::SQL_FOR_UPDATE;
+        }
+
+        return $sql;
+    }
+
+    /**
+     * Turn magic function calls into non-magic function calls
+     * for joinUsing syntax
+     *
+     * @param string $method
+     * @param array $args OPTIONAL Zend_Db_Table_Select query modifier
+     * @return Zend_Db_Select
+     * @throws Zend_Db_Select_Exception If an invalid method is called.
+     */
+    public function __call($method, array $args)
+    {
+        $matches = array();
+
+        /**
+         * Recognize methods for Has-Many cases:
+         * findParent<Class>()
+         * findParent<Class>By<Rule>()
+         * Use the non-greedy pattern repeat modifier e.g. \w+?
+         */
+        if (preg_match('/^join([a-zA-Z]*?)Using$/', $method, $matches)) {
+            $type = strtolower($matches[1]);
+            if ($type) {
+                $type .= ' join';
+                if (!in_array($type, self::$_joinTypes)) {
+                    require_once 'Zend/Db/Select/Exception.php';
+                    throw new Zend_Db_Select_Exception("Unrecognized method '$method()'");
+                }
+                if (in_array($type, array(self::CROSS_JOIN, self::NATURAL_JOIN))) {
+                    require_once 'Zend/Db/Select/Exception.php';
+                    throw new Zend_Db_Select_Exception("Cannot perform a joinUsing with method '$method()'");
+                }
+            } else {
+                $type = self::INNER_JOIN;
+            }
+            array_unshift($args, $type);
+            return call_user_func_array(array($this, '_joinUsing'), $args);
+        }
+
+        require_once 'Zend/Db/Select/Exception.php';
+        throw new Zend_Db_Select_Exception("Unrecognized method '$method()'");
+    }
+
+    /**
+     * Implements magic method.
+     *
+     * @return string This object as a SELECT string.
+     */
+    public function __toString()
+    {
+        try {
+            $sql = $this->assemble();
+        } catch (Exception $e) {
+            trigger_error($e->getMessage(), E_USER_WARNING);
+            $sql = '';
+        }
+        return (string)$sql;
+    }
+
+}