Add SqlCriteria class. Add SqlModel.find() with use SqlCriteria.

model/SqlCriteria.php

@@ -0,0 +1,86 @@
+<?php
+
+class SqlCriteria
+{
+    public $select = array('*');
+
+    public $distinct = '';
+
+    public $where = array();
+
+    public $order = array();
+
+    public $limit = '';
+
+    /**
+     * @return SqlCriteria
+     */
+    public static function getInstance()
+    {
+        return self;
+    }
+
+    /**
+     * @param $conditions array @ex array('field=?' => $value, 'field in ? => new DbExpr('(1,2,3)'))
+     * @return SqlCriteria
+     */
+    public function where($conditions)
+    {
+        $this->where = $conditions;
+        return $this;
+    }
+
+    /**
+     * @param $fields array()
+     * @param array $fields_to_desc
+     * @return SqlCriteria
+     */
+    public function order($fields, $fields_to_desc = array())
+    {
+        if (!is_array($fields)) {
+            $fields = array($fields);
+        }
+        foreach ($fields as  $term) {
+            $term = $this->db->quoteIdentifier($term) . (in_array($term, $fields_to_desc) ? ' DESC' : '');
+        }
+        $this->order = implode(',', $fields);
+        return $this;
+    }
+
+    /**
+     * @param $limit int
+     * @param $offset int
+     * @return SqlCriteria
+     */
+    public function limit($limit, $offset = 0)
+    {
+        if (empty($offset)) {
+            $this->limit = (int) $limit;
+        }
+        $this->limit = (int)$limit . ',' . (int) $offset;
+        return $this;
+    }
+
+    /**
+     * @param mixed $select array @ex array('field1', 'field2', 'field3' => 'field')
+     * @return string
+     */
+    public function select($select)
+    {
+        if (!is_array($select)) {
+            $select = array($select);
+        }
+        $this->select = implode(',', $select);
+        return $this;
+    }
+
+    /**
+     * @param $field string
+     * @return SqlCriteria
+     */
+    public function distinct($field)
+    {
+        $this->distinct = $field;
+        return $this;
+    }
+}

model/SqlModel.php

@@ -15,7 +15,6 @@
  */
 abstract class SqlModel extends Model
 {
-
     /**
      * @param string $ident
      * @return string Quoted identifier.
@@ -178,4 +177,35 @@ abstract class SqlModel extends Model
         return $result;
     }
 
+    /**
+     * @param $criteria SqlCriteria
+     */
+    public function find($criteria)
+    {
+        foreach ($criteria->select as $field => &$term) {
+            if (is_int($field)) {
+                $term = $this->db->quoteIdentifier($term);
+            } else {
+                $term = $this->db->quoteIdentifier($field) . ' as ' . $this->db->quoteIdentifier($term);
+            }
+        }
+        foreach ($criteria->where as $cond => &$term) {
+            $term = $this->db->quoteInto($cond, $term);
+        }
+        foreach ($criteria->order as $field => $term) {
+            if (!is_int($field) && $term == 'desc') {
+                $term = $term = $this->db->quoteIdentifier($field) . ' DESC';
+            } else {
+                $term = $this->db->quoteIdentifier($term);
+            }
+        }
+        if ($criteria->distinct != '') {
+            $criteria->distinct = 'DISTINCT ' . $this->db->quoteIdentifier($criteria->distinct);
+        }
+        $sql = 'SELECT ' . (($criteria->distinct) ? $criteria->distinct : implode(',', $criteria->select))
+            . ' FROM ' . $this->db->quoteIdentifier($this->table)
+            . (($criteria->where) ? (' WHERE ' . implode(' AND ', $criteria->where)) : '')
+            . (($criteria->order) ? (' ORDER BY ' . implode(',', $criteria->order)) : '')
+            . (($criteria->limit) ? (' LIMIT ' . implode(',',array_map(function($item){return intval($item);},explode(',',$criteria->limit)))) : '');
+    }
 }