Библиотека для cis, online, cms1

core/query/query.php

@@ -0,0 +1,206 @@
+<?php
+
+require_once 'table.php';
+require_once 'meta.php';
+
+/**
+ * Êëàññ äëÿ ñîñòàâëåíèÿ çàïðîñà
+ */
+class Query
+{
+    static $alias = 0;
+
+    public $table;
+    public $filter = array ();
+    public $calc   = array ();
+    public $order  = array ();    
+
+    /**
+     * Ñîçäàåò ïóñòîé çàðîñ
+     */
+    static function create()
+    {
+        return new Query();
+    }
+
+    /**
+     * Ìåòàäàííûå òàáëèöû
+     * @param string $name Èìÿ òàáëèöû
+     */
+    function getTableMeta($name) 
+    {
+    }
+    
+    /**
+     * Ñîçäàåò íîâûé çàïðîñ
+     * @param string $name Èìÿ òàáëèöû
+     *
+     * @return Query
+     */
+    public function from($name)
+    {
+        $result = clone $this;
+
+        $table = new Table();
+        $table->type  = 'simple';
+        $table->name  = $name;
+        $table->alias = "t" . self::$alias++;
+
+        $result->table = $table;
+        
+        return $result;
+    }
+    
+    /**
+     * Äîáàâëÿåò ê çàïðîñó óñëîâèå
+     * @param string $field Èìÿ ïîëÿ òàáëèöû
+     * @param string $op Èìÿ îïåðàòîðà 
+     * @param $value Çíà÷åíèå ïîëÿ
+     *
+     * @return Query     
+     */
+    public function filter($field, $op, $value)
+    {
+        $result = clone $this;
+        $result->filter [] = $result->table->alias ."." . $field . $op . "'" . $value . "'";
+        return $result;            
+    }
+
+    /**
+     * @param string $e Âûðàæåíèå
+     */
+    public function calc($e)
+    {
+        $result = clone $this;
+        $result->calc [] = $e;
+        return $result;
+    }
+
+    public function joinOn($first, $e) 
+    {
+        $result = $this->compose($first, array ('filter', 'calc', 'order'));
+        
+        $e = strtr($e, array ("a." => $this->table->alias . ".", 
+                              "b." => $first->table->alias . "."));
+
+        $table = new Table ();
+        $table->type  = 'join';
+        $table->name  = $this->table->name;
+        $table->alias = $this->table->alias;
+        $table->join  = $first->table;
+        $table->condition = $e;
+
+        $result->table = $table;
+
+        return $result;        
+    }
+
+    /**
+     * Îáüåäèíÿåò ïàðàìåòðû äâóõ çàðîñîâ
+     * @param Query $first 
+     * @pram array $list Ñïèñîê ïàðàìåòðîâ
+     * 
+     * @return Query
+     */
+    private function compose(Query $first, array $list)
+    {
+        $result = new Query();
+        foreach ($list as $name) {
+            $result->$name = array_merge($this->$name, $first->$name);
+        }
+        return $result;
+    }
+
+    /**
+     * Çàêîâû÷èâàåò çíà÷åíèå
+     */
+    public function quote ($value) 
+    {
+        return "'" . $value . "'";
+    }
+
+    /**
+     * Êîìïèëÿöèÿ òàáëèöû
+     * @param Table $table
+     * 
+     * @return string ×àñòü ñòðîêè SQL
+     */
+    private function table(Table $table)
+    {
+        if ($table->type == 'simple') {
+            return $table->name ." AS ".$table->alias;
+        }
+        if ($table->type == 'join') {
+            return $table->name ." AS ".$table->alias. " JOIN " . $this->table ($table->join) . " ON " . $table->condition;
+        }
+        return "";
+    }
+
+    /**
+     * Êîìïèëÿöèÿ WHERE
+     * 
+     * @return string ×àñòü ñòðîêè SQL
+     */
+    private function where ()
+    {
+        return implode(" AND ", $this->filter);
+    }  
+        
+    /**
+     * Êîìïèëÿöèÿ çàïðîñà â SELECT SQL
+     * 
+     * @return string SQL âûðàæåíèå
+     */
+    public function select()
+    {
+        return "SELECT " 
+               . ((!empty($this->calc))? implode (",", $this->calc): "*")
+               . " FROM "  . $this->table($this->table)
+               . ((!empty ($this->filter))? " WHERE " . $this->where() : "");
+    }
+
+    /**
+     * Êîìïèëÿöèÿ â DELETE
+     */
+    public function delete()
+    {
+        return "DELETE FROM " . $this->table->name  
+               . ((!empty ($this->filter))? " WHERE " . $this->where() : "");
+    }
+
+    private function add_prefix($prefix, $array) {
+        $result = array();
+        foreach ($array as $value) {
+            $result [] = $prefix . $value;
+        }
+        return $result;
+    }
+
+    /**
+     * Êîìïèëÿöèÿ â UPDATE
+     * TODO: Ðàçíûå òèïû çàïðîñîâ Query->update(); Query->select(), Query->insert();!!
+     * Âîçâðààùàþò statement
+     */
+    public function update($values)
+    {            
+        $pairs = array ();
+        foreach ($values as $key => $value) { // 
+            $pairs [] = $key . "=" . $this->quote ($value); 
+        }
+        return "UPDATE " . $this->table->name . " SET "
+               . implode(",", $pairs) 
+               . ((!empty($this->filter))? " WHERE " . $this->where() : "");
+    }
+
+    /**
+     * Êîìïèëÿöèÿ â INSERT
+     */
+    public function insert($values)
+    {
+        return "INSERT INTO ". $this->table->name . "(" 
+        . implode(",", array_keys($values)) 
+        . ") VALUES (" . implode(",", array_map(array($this, 'quote'), array_values($values))) . ")";
+    }
+}
+
+?>