Index: api/src/main/java/javax/jdo/JDOQLTypedQuery.java
===================================================================
--- api/src/main/java/javax/jdo/JDOQLTypedQuery.java	(revision 1841021)
+++ api/src/main/java/javax/jdo/JDOQLTypedQuery.java	(working copy)
@@ -22,8 +22,6 @@
 import java.util.List;
 import java.util.Map;
 
-import javax.jdo.FetchPlan;
-import javax.jdo.PersistenceManager;
 import javax.jdo.query.BooleanExpression;
 import javax.jdo.query.CharacterExpression;
 import javax.jdo.query.CollectionExpression;
@@ -30,6 +28,7 @@
 import javax.jdo.query.DateExpression;
 import javax.jdo.query.DateTimeExpression;
 import javax.jdo.query.Expression;
+import javax.jdo.query.IfThenElseExpression;
 import javax.jdo.query.ListExpression;
 import javax.jdo.query.MapExpression;
 import javax.jdo.query.NumericExpression;
@@ -170,6 +169,63 @@
     JDOQLTypedQuery<T> filter(BooleanExpression expr);
 
     /**
+     * Method to return an "IF (...) ... ELSE ..." expression for use in this query.
+     * @param type The type returned by the IfElse.
+     * @param cond The if condition
+     * @param thenValueExpr Expression for value to return when the if expression is met
+     * @param elseValueExpr Expression for value to return when the if expression is not met
+     * @return The IfThenElse expression
+     */
+    <V> IfThenElseExpression<V> ifThenElse(Class<V> type, BooleanExpression cond,
+                                           Expression<V> thenValueExpr, Expression<V> elseValueExpr);
+
+    /**
+     * Method to return an "IF (...) ... ELSE ..." expression for use in this query.
+     * @param cond The if condition
+     * @param thenValue Value to return when the if expression is met
+     * @param elseValueExpr Expression to return when the if expression is not met
+     * @return The IfThenElse expression
+     */
+    <V> IfThenElseExpression<V> ifThenElse(BooleanExpression cond, V thenValue, Expression<V> elseValueExpr);
+
+    /**
+     * Method to return an "IF (...) ... ELSE ..." expression for use in this query.
+     * @param cond The if condition
+     * @param thenValueExpr Expression to return when the if expression is met
+     * @param elseValue Value to return when the if expression is not met
+     * @return The IfThenElse expression
+     */
+    <V> IfThenElseExpression<V> ifThenElse(BooleanExpression cond, Expression<V> thenValueExpr, V elseValue);
+
+    /**
+     * Method to return an "IF (...) ... ELSE ..." expression for use in this query.
+     * @param cond The if condition
+     * @param thenValue Value to return when the if expression is met
+     * @param elseValue Value to return when the if expression is not met
+     * @return The IfThenElse expression
+     */
+    <V> IfThenElseExpression<V> ifThenElse(BooleanExpression cond, V thenValue, V elseValue);
+
+    /**
+     * Method to return an "IF (...) ... ELSE ..." expression for use in this query.
+     * @param type The type returned by the IfElse.
+     * @param cond The if condition
+     * @param thenValueExpr Expression for value to return when the if expression is met
+     * @param <V>
+     * @return
+     */
+    <V> IfThenElseExpression<V> ifThen(Class<V> type, BooleanExpression cond, Expression<V> thenValueExpr);
+
+    /**
+     * Method to return an "IF (...) ... ELSE ..." expression for use in this query.
+     * @param cond The if condition
+     * @param thenValue Value to return when the if expression is met
+     * @param <V>
+     * @return
+     */
+    <V> IfThenElseExpression<V> ifThen(BooleanExpression cond, V thenValue);
+
+    /**
      * Method to set the grouping(s) for the query.
      * @param exprs Grouping expression(s)
      * @return The query
Index: api/src/main/java/javax/jdo/query/IfThenElseExpression.java
===================================================================
--- api/src/main/java/javax/jdo/query/IfThenElseExpression.java	(nonexistent)
+++ api/src/main/java/javax/jdo/query/IfThenElseExpression.java	(working copy)
@@ -0,0 +1,60 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package javax.jdo.query;
+
+/**
+ * Representation of an IF-THEN-ELSE expression.
+ *
+ * @param <T> Java type
+ */
+public interface IfThenElseExpression<T> extends ComparableExpression<T> {
+
+    /**
+     * Method to add an "IF (...) ..." clause.
+     * If called multiple times, will add extra "IF (...) ..." or "ELSE IF (...) ..."
+     * @param cond The if expression
+     * @param thenValueExpr Expression to return when the if expression is met
+     * @return This expression
+     */
+    IfThenElseExpression<T> ifThen(BooleanExpression cond, Expression<T> thenValueExpr);
+
+    /**
+     * Method to add an "IF (...) ..." clause.
+     * If called multiple times, will add extra "IF (...) ..." or "ELSE IF (...) ..."
+     * @param cond The if condition
+     * @param thenValue Value to return when the if expression is met
+     * @return This expression
+     */
+    IfThenElseExpression<T> ifThen(BooleanExpression cond, T thenValue);
+
+    /**
+     * Method to add the "ELSE ..." clause.
+     * If called multiple times will replace the previous else clause
+     * @param elseValueExpr Expression for value to return when the if expression is not met
+     * @return This expression
+     */
+    IfThenElseExpression<T> elseEnd(Expression<T> elseValueExpr);
+
+    /**
+     * Method to add the "ELSE ..." clause.
+     * If called multiple times will replace the previous else clause
+     * @param elseValue Value to return when the if expression is not met
+     * @return This expression
+     */
+    IfThenElseExpression<T> elseEnd(T elseValue);
+    
+}
Index: api/src/main/java/javax/jdo/query/ComparableExpression.java
===================================================================
--- api/src/main/java/javax/jdo/query/ComparableExpression.java	(revision 1841021)
+++ api/src/main/java/javax/jdo/query/ComparableExpression.java	(working copy)
@@ -81,15 +81,15 @@
 
     /**
      * Method to return a numeric expression representing the aggregated minimum of this expression.
-     * @return Numeric expression for the minimum
+     * @return expression for the minimum
      */
-    NumericExpression<T> min();
+    ComparableExpression<T> min();
 
     /**
      * Method to return a numeric expression representing the aggregated maximum of this expression.
-     * @return Numeric expression for the maximum
+     * @return expression for the maximum
      */
-    NumericExpression<T> max();
+    ComparableExpression<T> max();
 
     /**
      * Method to return an order expression for this expression in ascending order.
Index: api/src/main/java/javax/jdo/query/NumericExpression.java
===================================================================
--- api/src/main/java/javax/jdo/query/NumericExpression.java	(revision 1841021)
+++ api/src/main/java/javax/jdo/query/NumericExpression.java	(working copy)
@@ -21,7 +21,7 @@
  * 
  * @param <T> Number type
  */
-public interface NumericExpression<T> extends ComparableExpression<Number>
+public interface NumericExpression<T> extends ComparableExpression<T>
 {
     /**
      * Method to return an expression for this expression added to the passed expression.
@@ -28,7 +28,7 @@
      * @param expr The other expression
      * @return The summation
      */
-    NumericExpression add(Expression expr);
+    NumericExpression<T> add(Expression<T> expr);
 
     /**
      * Method to return an expression for this expression added to the passed number.
@@ -35,7 +35,7 @@
      * @param num Number to add
      * @return The summation
      */
-    NumericExpression add(Number num);
+    NumericExpression<T> add(Number num);
 
     /**
      * Method to return an expression for this expression subtracting the passed expression.
@@ -42,7 +42,7 @@
      * @param expr The other expression
      * @return The difference
      */
-    NumericExpression sub(Expression expr);
+    NumericExpression<T> sub(Expression<T> expr);
 
     /**
      * Method to return an expression for this expression subtracting the passed number.
@@ -49,7 +49,7 @@
      * @param num Number to subtract
      * @return The difference
      */
-    NumericExpression sub(Number num);
+    NumericExpression<T> sub(Number num);
 
     /**
      * Method to return an expression for this expression multiplied by the passed expression.
@@ -56,7 +56,7 @@
      * @param expr The other expression
      * @return The multiplication
      */
-    NumericExpression mul(Expression expr);
+    NumericExpression<T> mul(Expression<T> expr);
 
     /**
      * Method to return an expression for this expression multiplied by the passed number.
@@ -63,7 +63,7 @@
      * @param num Number
      * @return The multiplication
      */
-    NumericExpression mul(Number num);
+    NumericExpression<T> mul(Number num);
 
     /**
      * Method to return an expression for this expression divided by the passed expression.
@@ -70,7 +70,7 @@
      * @param expr The other expression
      * @return The division
      */
-    NumericExpression div(Expression expr);
+    NumericExpression<T> div(Expression<T> expr);
 
     /**
      * Method to return an expression for this expression divided by the passed number.
@@ -77,7 +77,7 @@
      * @param num Number to divide by
      * @return The division
      */
-    NumericExpression div(Number num);
+    NumericExpression<T> div(Number num);
 
     /**
      * Method to return an expression for this expression modulus the passed expression (<pre>a % b</pre>).
@@ -84,7 +84,7 @@
      * @param expr The other expression
      * @return The modulus
      */
-    NumericExpression mod(Expression expr);
+    NumericExpression<T> mod(Expression<T> expr);
 
     /**
      * Method to return an expression for this expression modulus the passed number.
@@ -91,19 +91,19 @@
      * @param num Number
      * @return The modulus
      */
-    NumericExpression mod(Number num);
+    NumericExpression<T> mod(Number num);
 
     /**
      * Method to return an expression that is the current expression negated.
      * @return The negated expression
      */
-    NumericExpression neg();
+    NumericExpression<T> neg();
 
     /**
      * Method to return an expression that is the complement of the current expression.
      * @return The complement expression
      */
-    NumericExpression com();
+    NumericExpression<T> com();
 
     /**
      * Method to return a numeric expression representing the aggregated average of this expression.
@@ -115,79 +115,79 @@
      * Method to return a numeric expression representing the aggregated sum of this expression.
      * @return Numeric expression for the sum
      */
-    NumericExpression sum();
+    NumericExpression<T> sum();
 
     /**
      * Method to return the absolute value expression of this expression.
      * @return The absolute value expression
      */
-    NumericExpression abs();
+    NumericExpression<T> abs();
 
     /**
      * Method to return the square-root value expression of this expression.
      * @return The square-root value expression
      */
-    NumericExpression sqrt();
+    NumericExpression<Double> sqrt();
 
     /**
      * Method to return the arc cosine value expression of this expression.
      * @return The arc cosine value expression
      */
-    NumericExpression acos();
+    NumericExpression<Double> acos();
 
     /**
      * Method to return the arc sine value expression of this expression.
      * @return The arc sine value expression
      */
-    NumericExpression asin();
+    NumericExpression<Double> asin();
 
     /**
      * Method to return the arc tangent value expression of this expression.
      * @return The arc tangent value expression
      */
-    NumericExpression atan();
+    NumericExpression<Double> atan();
 
     /**
      * Method to return the sine value expression of this expression.
      * @return The sine value expression
      */
-    NumericExpression sin();
+    NumericExpression<Double> sin();
 
     /**
      * Method to return the cosine value expression of this expression.
      * @return The cosine value expression
      */
-    NumericExpression cos();
+    NumericExpression<Double> cos();
 
     /**
      * Method to return the tangent value expression of this expression.
      * @return The tangent value expression
      */
-    NumericExpression tan();
+    NumericExpression<Double> tan();
 
     /**
      * Method to return the exponential value expression of this expression.
      * @return The exponential value expression
      */
-    NumericExpression exp();
+    NumericExpression<T> exp();
 
     /**
      * Method to return the logarithm value expression of this expression.
      * @return The logarithm value expression
      */
-    NumericExpression log();
+    NumericExpression<T> log();
 
     /**
      * Method to return the ceiling value expression of this expression.
      * @return The ceiling value expression
      */
-    NumericExpression ceil();
+    NumericExpression<T> ceil();
 
     /**
      * Method to return the floor value expression of this expression.
      * @return The floor value expression
      */
-    NumericExpression floor();
+    NumericExpression<T> floor();
 
     /**
      * Method to return a bitwise AND expression for this expression with the supplied bit path.
@@ -194,7 +194,7 @@
      * @param bitExpr Bit expression
      * @return Bitwise AND expression
      */
-    NumericExpression bAnd(NumericExpression bitExpr);
+    NumericExpression<T> bAnd(NumericExpression<T> bitExpr);
 
     /**
      * Method to return a bitwise OR expression for this expression with the supplied bit path.
@@ -201,7 +201,7 @@
      * @param bitExpr Bit expression
      * @return Bitwise OR expression
      */
-    NumericExpression bOr(NumericExpression bitExpr);
+    NumericExpression<T> bOr(NumericExpression<T> bitExpr);
 
     /**
      * Method to return a bitwise XOR expression for this expression with the supplied bit path.
@@ -208,5 +208,5 @@
      * @param bitExpr Bit expression
      * @return Bitwise XOR expression
      */
-    NumericExpression bXor(NumericExpression bitExpr);
+    NumericExpression<T> bXor(NumericExpression<T> bitExpr);
 }