Add javadocs #555

querydsl-sql/src/main/java/com/mysema/query/sql/SQLExpressions.java

@@ -478,6 +478,9 @@ public static <T> WindowOver<T> lag(Expression<T> expr) {
     }
 
     /**
+     * divides an ordered data set into a number of buckets indicated by expr and assigns the
+     * appropriate bucket number to each row
+     *
      * @param num
      * @return
      */
@@ -565,6 +568,8 @@ public static WindowOver<Long> rowNumber() {
     }
 
     /**
+     * returns the sample standard deviation of expr, a set of numbers.
+     *
      * @param expr
      * @return
      */
@@ -581,6 +586,8 @@ public static <T extends Number> WindowOver<T> stddevDistinct(Expression<T> expr
     }
 
     /**
+     * returns the population standard deviation and returns the square root of the population variance.
+     *
      * @param expr
      * @return
      */
@@ -589,6 +596,8 @@ public static <T extends Number> WindowOver<T> stddevPop(Expression<T> expr) {
     }
 
     /**
+     * returns the cumulative sample standard deviation and returns the square root of the sample variance.
+     *
      * @param expr
      * @return
      */
@@ -597,6 +606,8 @@ public static <T extends Number> WindowOver<T> stddevSamp(Expression<T> expr) {
     }
 
     /**
+     * returns the variance of expr
+     *
      * @param expr
      * @return
      */
@@ -605,6 +616,8 @@ public static <T extends Number> WindowOver<T> variance(Expression<T> expr) {
     }
 
     /**
+     * returns the population variance of a set of numbers after discarding the nulls in this set.
+     *
      * @param expr
      * @return
      */
@@ -613,6 +626,8 @@ public static <T extends Number> WindowOver<T> varPop(Expression<T> expr) {
     }
 
     /**
+     * returns the sample variance of a set of numbers after discarding the nulls in this set.
+     *
      * @param expr
      * @return
      */