Index: rdbms/Criteria.class.php
===================================================================
--- rdbms/Criteria.class.php	(revision 6389)
+++ rdbms/Criteria.class.php	(working copy)
@@ -64,12 +64,17 @@
      * @param   mixed value
      * @param   string comparison default EQUAL
      */
-    function add($key, $value, $comparison= EQUAL) {
+    function add($key, $value= NULL, $comparison= EQUAL) {
       static $nullMapping= array(
         EQUAL     => IS,
         NOT_EQUAL => IS_NOT
       );
       
+      if (is('rdbms.criterion.Criterion', $key)) {
+        $this->conditions[]= &$key;
+        return;
+      }
+      
       // Automatically convert '= NULL' to 'is NULL', former is not valid ANSI-SQL
       if (NULL === $value && isset($nullMapping[$comparison]))
         $comparison= $nullMapping[$comparison];
@@ -145,6 +150,11 @@
       if (!empty($this->conditions)) {
         $sql.= ' where ';
         foreach ($this->conditions as $condition) {
+          if (is('rdbms.criterion.Criterion', $condition)) {
+            $sql.= $condition->asSql($db, $types).' and ';
+            continue;
+          }
+        
           if (!isset($types[$condition[0]])) {
             return throw(new SQLStateException('Field "'.$condition[0].'" unknown'));
           }
Index: rdbms/criterion/Restrictions.class.php
===================================================================
--- rdbms/criterion/Restrictions.class.php	(revision 0)
+++ rdbms/criterion/Restrictions.class.php	(revision 0)
@@ -0,0 +1,205 @@
+<?php
+/* This class is part of the XP framework
+ *
+ * $Id$ 
+ */
+
+  uses(
+    'rdbms.criterion.LogicalExpression',
+    'rdbms.criterion.BetweenExpression',
+    'rdbms.criterion.NegationExpression',
+    'rdbms.criterion.SimpleExpression'
+  );
+
+  /**
+   * Factory for criterion types
+   *
+   * @test     xp://net.xp_framework.unittest.rdbms.CriteriaTest
+   * @purpose  Factory
+   */
+  class Restrictions extends Object {
+
+    /**
+     * Apply an "in" constraint to the named property
+     *
+     * @model   static
+     * @access  public
+     * @param   string field
+     * @param   mixed[] values
+     * @return  &rdbms.criterion.SimpleExpression
+     */
+    function &in($field, $values) {
+      return new SimpleExpression($field, $values, IN);
+    }
+
+    /**
+     * Apply an "not in" constraint to the named property
+     *
+     * @model   static
+     * @access  public
+     * @param   string field
+     * @param   mixed[] values
+     * @return  &rdbms.criterion.SimpleExpression
+     */
+    function &notIn($field, $values) {
+      return new SimpleExpression($field, $values, NOT_IN);
+    }
+
+    /**
+     * Apply a "like" constraint to the named property
+     *
+     * @model   static
+     * @access  public
+     * @param   string field
+     * @param   mixed value
+     * @return  &rdbms.criterion.SimpleExpression
+     */
+    function &like($field, $value) {
+      return new SimpleExpression($field, $value, LIKE);
+    }
+
+    /**
+     * Apply a case-insensitive "like" constraint to the named property
+     *
+     * @see     php://sql_regcase
+     * @model   static
+     * @access  public
+     * @param   string field
+     * @param   mixed value
+     * @return  &rdbms.criterion.SimpleExpression
+     */
+    function &ilike($field, $value) {
+      return new SimpleExpression($field, sql_regcase($value), LIKE);
+    }
+        
+    /**
+     * Apply an "equal" constraint to the named property
+     *
+     * @model   static
+     * @access  public
+     * @param   string field
+     * @param   mixed value
+     * @return  &rdbms.criterion.SimpleExpression
+     */
+    function &equal($field, $value) {
+      return new SimpleExpression($field, $value, EQUAL);
+    }
+
+    /**
+     * Apply a "not equal" constraint to the named property
+     *
+     * @model   static
+     * @access  public
+     * @param   string field
+     * @param   mixed value
+     * @return  &rdbms.criterion.SimpleExpression
+     */
+    function &notEqual($field, $value) {
+      return new SimpleExpression($field, $value, NOT_EQUAL);
+    }
+
+    /**
+     * Apply a "less than" constraint to the named property
+     *
+     * @model   static
+     * @access  public
+     * @param   string field
+     * @param   mixed value
+     * @return  &rdbms.criterion.SimpleExpression
+     */
+    function &lessThan($field, $value) {
+      return new SimpleExpression($field, $value, LESS_THAN);
+    }
+
+    /**
+     * Apply a "greater than" constraint to the named property
+     *
+     * @model   static
+     * @access  public
+     * @param   string field
+     * @param   mixed value
+     * @return  &rdbms.criterion.SimpleExpression
+     */
+    function &greaterThan($field, $value) {
+      return new SimpleExpression($field, $value, GREATER_THAN);
+    }
+
+    /**
+     * Apply a "less than or equal to" constraint to the named property
+     *
+     * @model   static
+     * @access  public
+     * @param   string field
+     * @param   mixed value
+     * @return  &rdbms.criterion.SimpleExpression
+     */
+    function &lessThanOrEqualTo($field, $value) {
+      return new SimpleExpression($field, $value, LESS_EQUAL);
+    }
+
+    /**
+     * Apply a "greater than or equal to" constraint to the named property
+     *
+     * @model   static
+     * @access  public
+     * @param   string field
+     * @param   mixed value
+     * @return  &rdbms.criterion.SimpleExpression
+     */
+    function &greaterThanOrEqualTo($field, $value) {
+      return new SimpleExpression($field, $value, GREATER_EQUAL);
+    }
+
+    /**
+     * Apply a "between" constraint to the named property
+     *
+     * @model   static
+     * @access  public
+     * @param   string field
+     * @param   mixed lo
+     * @param   mixed hi
+     * @return  &rdbms.criterion.SimpleExpression
+     */
+    function &between($field, $lo, $hi) {
+      return new BetweenExpression($field, $lo, $hi);
+    }
+
+    /**
+     * Return the disjuction of two expressions
+     *
+     * @model   static
+     * @access  public
+     * @param   &rdbms.criterion.Criterion left
+     * @param   &rdbms.criterion.Criterion right
+     * @return  &rdbms.criterion.LogicalExpression
+     */
+    function &eitherOf(&$left, &$right) {
+      return new LogicalExpression($left, $right, LOGICAL_OR);
+    }
+
+    /**
+     * Return the conjuction of two expressions
+     *
+     * @model   static
+     * @access  public
+     * @param   &rdbms.criterion.Criterion left
+     * @param   &rdbms.criterion.Criterion right
+     * @return  &rdbms.criterion.LogicalExpression
+     */
+    function &bothOf(&$left, &$right) {
+      return new LogicalExpression($left, $right, LOGICAL_AND);
+    }
+
+    /**
+     * Return the negation of an expression
+     *
+     * @model   static
+     * @access  public
+     * @param   &rdbms.criterion.Criterion expression
+     * @return  &rdbms.criterion.NegationExpression
+     */
+    function &not(&$expression) {
+      return new NegationExpression($expression);
+    }
+  }
+?>
Index: rdbms/criterion/SimpleExpression.class.php
===================================================================
--- rdbms/criterion/SimpleExpression.class.php	(revision 0)
+++ rdbms/criterion/SimpleExpression.class.php	(revision 0)
@@ -0,0 +1,76 @@
+<?php
+/* This class is part of the XP framework
+ *
+ * $Id$ 
+ */
+
+  /**
+   * Simple expression
+   *
+   * @purpose  Criterion
+   */
+  class SimpleExpression extends Object {
+    var
+      $field  = '',
+      $value  = NULL,
+      $op     = '';
+
+    /**
+     * Constructor
+     *
+     * The operation may be one of:
+     * <ul>
+     *   <li>IN</li>
+     *   <li>NOT_IN</li>
+     *   <li>LIKE</li>
+     *   <li>EQUAL</li>
+     *   <li>NOT_EQUAL</li>
+     *   <li>LESS_THAN</li>
+     *   <li>GREATER_THAN</li>
+     *   <li>LESS_EQUAL</li>
+     *   <li>GREATER_EQUAL</li>
+     * </ul>
+     *
+     * @access  public
+     * @param   string field
+     * @param   mixed value
+     * @param   string op default EQUAL
+     */
+    function __construct($field, $value, $op= EQUAL) {
+      static $nullMapping= array(
+        EQUAL     => IS,
+        NOT_EQUAL => IS_NOT
+      );
+
+      $this->field= $field;
+      $this->value= &$value;
+
+      // Automatically convert '= NULL' to 'is NULL', former is not valid ANSI-SQL
+      if (NULL === $value && isset($nullMapping[$op])) {
+        $op= $nullMapping[$op];
+      }
+      $this->op= $op;
+    }
+  
+    /**
+     * Returns the fragment SQL
+     *
+     * @access  public
+     * @param   &rdbms.DBConnection conn
+     * @param   array types
+     * @return  string
+     * @throws  rdbms.SQLStateException
+     */
+    function asSql(&$conn, $types) { 
+      if (!isset($types[$this->field])) {
+        return throw(new SQLStateException('Field "'.$this->field.'" unknown'));
+      }
+
+      return $this->field.' '.$conn->prepare(
+        str_replace('?', $types[$this->field], $this->op), 
+        $this->value
+      );      
+    }
+
+  } implements(__FILE__, 'rdbms.criterion.Criterion');
+?>
Index: rdbms/criterion/BetweenExpression.class.php
===================================================================
--- rdbms/criterion/BetweenExpression.class.php	(revision 0)
+++ rdbms/criterion/BetweenExpression.class.php	(revision 0)
@@ -0,0 +1,54 @@
+<?php
+/* This class is part of the XP framework
+ *
+ * $Id$ 
+ */
+
+  /**
+   * Between expression
+   *
+   * @purpose  Criterion
+   */
+  class BetweenExpression extends Object {
+    var
+      $field  = '',
+      $lo     = NULL,
+      $hi     = NULL;
+
+    /**
+     * Constructor
+     *
+     * @access  public
+     * @param   string field
+     * @param   mixed lo
+     * @param   mixed hi
+     */
+    function __construct($field, $lo, $hi) {
+      $this->field= $field;
+      $this->lo= &$lo;
+      $this->hi= &$hi;
+    }
+  
+    /**
+     * Returns the fragment SQL
+     *
+     * @access  public
+     * @param   &rdbms.DBConnection conn
+     * @param   array types
+     * @return  string
+     * @throws  rdbms.SQLStateException
+     */
+    function asSql(&$conn, $types) { 
+      if (!isset($types[$this->field])) {
+        return throw(new SQLStateException('Field "'.$this->field.'" unknown'));
+      }
+
+      return $this->field.' between '.$conn->prepare(
+        $types[$this->field].' and '.$types[$this->field],
+        $this->lo,
+        $this->hi
+      );
+    }
+
+  } implements(__FILE__, 'rdbms.criterion.Criterion');
+?>
Index: rdbms/criterion/LogicalExpression.class.php
===================================================================
--- rdbms/criterion/LogicalExpression.class.php	(revision 0)
+++ rdbms/criterion/LogicalExpression.class.php	(revision 0)
@@ -0,0 +1,54 @@
+<?php
+/* This class is part of the XP framework
+ *
+ * $Id$ 
+ */
+
+  define('LOGICAL_AND', 'and');
+  define('LOGICAL_OR',  'or');
+
+  /**
+   * Logical expression
+   *
+   * @purpose  Criterion
+   */
+  class LogicalExpression extends Object {
+    var
+      $left   = NULL,
+      $right  = NULL,
+      $op     = '';
+
+    /**
+     * Constructor
+     *
+     * @access  public
+     * @param   &rdbms.criterion.Criterion left
+     * @param   &rdbms.criterion.Criterion right
+     * @param   string op one of the LOGICAL_* constants
+     */
+    function __construct(&$left, &$right, $op) {
+      $this->left= &$left;
+      $this->right= &$right;
+      $this->op= $op;
+    }
+  
+    /**
+     * Returns the fragment SQL
+     *
+     * @access  public
+     * @param   &rdbms.DBConnection conn
+     * @param   array types
+     * @return  string
+     * @throws  rdbms.SQLStateException
+     */
+    function asSql(&$conn, $types) { 
+      return $conn->prepare(
+        '(%c %c %c)', 
+        $this->left->asSql($conn, $types),
+        $this->op,
+        $this->right->asSql($conn, $types)
+      );
+    }
+
+  } implements(__FILE__, 'rdbms.criterion.Criterion');
+?>
Index: rdbms/criterion/Criterion.class.php
===================================================================
--- rdbms/criterion/Criterion.class.php	(revision 0)
+++ rdbms/criterion/Criterion.class.php	(revision 0)
@@ -0,0 +1,28 @@
+<?php
+/* This class is part of the XP framework
+ *
+ * $Id$ 
+ */
+
+  uses('rdbms.SQLStateException');
+
+  /**
+   * Represents a query criterion to be used in a Criteria query
+   *
+   * @see      xp://rdbms.Criteria#add
+   * @purpose  Interface
+   */
+  class Criterion extends Interface {
+  
+    /**
+     * Returns the fragment SQL
+     *
+     * @access  public
+     * @param   &rdbms.DBConnection conn
+     * @param   array types
+     * @return  string
+     * @throws  rdbms.SQLStateException
+     */
+    function asSql(&$conn, $types) { }
+  }
+?>
Index: rdbms/criterion/NegationExpression.class.php
===================================================================
--- rdbms/criterion/NegationExpression.class.php	(revision 0)
+++ rdbms/criterion/NegationExpression.class.php	(revision 0)
@@ -0,0 +1,40 @@
+<?php
+/* This class is part of the XP framework
+ *
+ * $Id$ 
+ */
+
+  /**
+   * Negates another criterion
+   *
+   * @purpose  Criterion
+   */
+  class NegationExpression extends Object {
+    var
+      $criterion  = NULL;
+
+    /**
+     * Constructor
+     *
+     * @access  public
+     * @param   &rdbms.criterion.Criterion criterion
+     */
+    function __construct(&$criterion) {
+      $this->criterion= &$criterion;
+    }
+  
+    /**
+     * Returns the fragment SQL
+     *
+     * @access  public
+     * @param   &rdbms.DBConnection conn
+     * @param   array types
+     * @return  string
+     * @throws  rdbms.SQLStateException
+     */
+    function asSql(&$conn, $types) { 
+      return $conn->prepare('not (%c)', $this->criterion->asSql($conn, $types));
+    }
+
+  } implements(__FILE__, 'rdbms.criterion.Criterion');
+?>
Index: rdbms/criterion/Property.class.php
===================================================================
--- rdbms/criterion/Property.class.php	(revision 0)
+++ rdbms/criterion/Property.class.php	(revision 0)
@@ -0,0 +1,168 @@
+<?php
+/* This class is part of the XP framework
+ *
+ * $Id$ 
+ */
+
+  uses('rdbms.criterion.Restrictions');
+
+  /**
+   * Factory for criterion types
+   *
+   * @purpose  Factory
+   */
+  class Property extends Object {
+    var 
+      $name= '';
+
+    /**
+     * Constructor
+     *
+     * @access  protected
+     * @param   string name
+     */
+    function __construct($name) {
+      $this->name= $name;
+    }
+
+    /**
+     * Retrieve a property instance by name
+     *
+     * @model   static
+     * @access  public
+     * @param   string name
+     * @return  &rdbms.criterion.Property
+     */
+    function &forName($name) {
+      static $instances= array();
+      
+      if (!isset($instances[$name])) {
+        $instances[$name]= &new Property($name);
+      }
+      return $instances[$name];
+    }
+
+    /**
+     * Apply an "in" constraint to the named property
+     *
+     * @access  public
+     * @param   mixed[] values
+     * @return  &rdbms.criterion.SimpleExpression
+     */
+    function &in($values) {
+      return Restrictions::in($this->name, $values);
+    }
+
+    /**
+     * Apply an "not in" constraint to the named property
+     *
+     * @access  public
+     * @param   mixed[] values
+     * @return  &rdbms.criterion.SimpleExpression
+     */
+    function &notIn($values) {
+      return Restrictions::notIn($this->name, $values);
+    }
+
+    /**
+     * Apply a "like" constraint to the named property
+     *
+     * @access  public
+     * @param   mixed value
+     * @return  &rdbms.criterion.SimpleExpression
+     */
+    function &like($value) {
+      return Restrictions::like($this->name, $value);
+    }
+
+    /**
+     * Apply a case-insensitive "like" constraint to the named property
+     *
+     * @see     php://sql_regcase
+     * @access  public
+     * @param   mixed value
+     * @return  &rdbms.criterion.SimpleExpression
+     */
+    function &ilike($value) {
+      return Restrictions::ilike($this->name, $value);
+    }
+        
+    /**
+     * Apply an "equal" constraint to the named property
+     *
+     * @access  public
+     * @param   mixed value
+     * @return  &rdbms.criterion.SimpleExpression
+     */
+    function &equal($value) {
+      return Restrictions::equal($this->name, $value);
+    }
+
+    /**
+     * Apply a "not equal" constraint to the named property
+     *
+     * @access  public
+     * @param   mixed value
+     * @return  &rdbms.criterion.SimpleExpression
+     */
+    function &notEqual($value) {
+      return Restrictions::notEqual($this->name, $value);
+    }
+
+    /**
+     * Apply a "less than" constraint to the named property
+     *
+     * @access  public
+     * @param   mixed value
+     * @return  &rdbms.criterion.SimpleExpression
+     */
+    function &lessThan($value) {
+      return Restrictions::lessThan($this->name, $value);
+    }
+
+    /**
+     * Apply a "greater than" constraint to the named property
+     *
+     * @access  public
+     * @param   mixed value
+     * @return  &rdbms.criterion.SimpleExpression
+     */
+    function &greaterThan($value) {
+      return Restrictions::greaterThan($this->name, $value);
+    }
+
+    /**
+     * Apply a "less than or equal to" constraint to the named property
+     *
+     * @access  public
+     * @param   mixed value
+     * @return  &rdbms.criterion.SimpleExpression
+     */
+    function &lessThanOrEqualTo($value) {
+      return Restrictions::lessThanOrEqualTo($this->name, $value);
+    }
+
+    /**
+     * Apply a "greater than or equal to" constraint to the named property
+     *
+     * @access  public
+     * @param   mixed value
+     * @return  &rdbms.criterion.SimpleExpression
+     */
+    function &greaterThanOrEqualTo($value) {
+      return Restrictions::greaterThanOrEqualTo($this->name, $value);
+    }
+
+    /**
+     * Apply a "between" constraint to the named property
+     *
+     * @access  public
+     * @param   mixed lo
+     * @param   mixed hi
+     * @return  &rdbms.criterion.SimpleExpression
+     */
+    function &between($lo, $hi) {
+      return Restrictions::between($this->name, $lo, $hi);
+    }
+  }
+?>
Index: net/xp_framework/unittest/rdbms/CriteriaTest.class.php
===================================================================
--- net/xp_framework/unittest/rdbms/CriteriaTest.class.php	(revision 6389)
+++ net/xp_framework/unittest/rdbms/CriteriaTest.class.php	(working copy)
@@ -6,6 +6,8 @@
  
   uses(
     'rdbms.Criteria', 
+    'rdbms.criterion.Restrictions', 
+    'rdbms.criterion.Property', 
     'rdbms.DriverManager',
     'net.xp_framework.unittest.rdbms.dataset.Job',
     'util.profiling.unittest.TestCase'
@@ -14,6 +16,10 @@
   /**
    * Test criteria class
    *
+   * Note we're relying on the connection to be a sybase connection -
+   * otherwise, quoting and date representation may change and make
+   * this testcase fail.
+   *
    * @see      xp://rdbms.Criteria
    * @purpose  Unit Test
    */
@@ -94,13 +100,34 @@
         $c->addOrderBy('valid_from');
       }
 
-      // Note we're relying on the connection to be a sybase connection -
-      // otherwise, quoting and date representation may change and make
-      // this test fail.
       $this->assertSql(
         'where job_id = 1 and valid_from >= "2006-01-01 12:00AM" and title like "Hello%" order by valid_from asc', 
         $c
       );
     }
+    
+    /**
+     * Tests the rdbms.criterion API
+     *
+     * @see     xp://rdbms.criterion.Property
+     * @see     xp://rdbms.criterion.Restrictions
+     * @access  public
+     */
+    #[@test]
+    function restrictionsFactory() {
+      $job_id= &Property::forName('job_id');
+      $c= &new Criteria(Restrictions::eitherOf(
+        Restrictions::not($job_id->in(array(1, 2, 3))),
+        Restrictions::bothOf(
+          Restrictions::like('title', 'Hello%'),
+          Restrictions::greaterThan('valid_from', new Date('2006-01-01'))
+        )
+      ));
+
+      $this->assertSql(
+        'where (not (job_id in (1, 2, 3)) or (title like "Hello%" and valid_from > "2006-01-01 12:00AM"))',
+        $c
+      );
+    }
   }
 ?>