Tests added for percentile and median functions

mysql-test/t/win_percentile.test

+CREATE TABLE t1 (name CHAR(10), test double, score DECIMAL(19,4));
+INSERT INTO t1 VALUES
+('Chun', 0, 3), ('Chun', 0, 7),
+('Kaolin', 0.5, 3), ('Kaolin', 0.6, 7),
+('Kaolin', 0.5, 4),
+('Tatiana', 0.8, 4), ('Tata', 0.8, 4);
+
+select name, percentile_cont(0.5)  within group(order by score) over (partition by name) as c from t1;
+
+--echo no partition clause
+select name, percentile_disc(0.5) within group(order by score)  over ()  from t1;
+select name, percentile_cont(0.5) within group(order by score)  over ()  from t1;
+
+--echo argument set to null
+--error ER_WRONG_TYPE_OF_ARGUMENT
+select name, percentile_cont(null)  within group(order by score) over (partition by name) from t1;
+--error ER_WRONG_TYPE_OF_ARGUMENT
+select name, percentile_disc(null)  within group(order by score) over (partition by name) from t1;
+
+--echo subqueries having percentile functions
+select * from ( select name , percentile_cont(0.5) within group ( order by score) over (partition by name ) from t1 ) as t;
+select * from ( select name , percentile_disc(0.5) within group ( order by score) over (partition by name ) from t1 ) as t;
+select name from t1 a where (select  percentile_disc(0.5) within group (order by score) over (partition by name) from t1 b limit 1) >= 0.5;
+
+--echo disallowed fields in order by
+--error ER_WRONG_TYPE_FOR_PERCENTILE_CONT
+select score,  percentile_cont(0.5)  within group(order by name) over (partition by score) from t1;
+select score,  percentile_disc(0.5)  within group(order by name) over (partition by score) from t1;
+
+--echo order by clause has more than one element
+--error ER_PARSE_ERROR
+select percentile_disc(0.5) within group(order by score,test) over (partition by name) from t1;
+--error ER_PARSE_ERROR
+select percentile_cont(0.5) within group(order by score,test) over (partition by name) from t1;
+
+--echo parameter value should be in the range of [0,1]
+--error ER_ARGUMENT_OUT_OF_RANGE
+select percentile_disc(1.5) within group(order by score) over (partition by name) from t1;
+--error ER_ARGUMENT_OUT_OF_RANGE
+select percentile_cont(1.5) within group(order by score) over (partition by name) from t1;
+
+--error ER_ARGUMENT_NOT_CONSTANT
+select name,percentile_cont(test) within group(order by score) over (partition by name) from t1;
+--error ER_ARGUMENT_NOT_CONSTANT
+select name, percentile_disc(test) within group(order by score) over (partition by name) from t1;
+
+--echo only numerical types are allowed as argument to percentile functions
+--error ER_WRONG_TYPE_OF_ARGUMENT
+select name, percentile_cont(name) within group(order by score) over (partition by name) from t1;
+
+--echo complete query with partition column
+select name,cume_dist() over (partition by name order by score), percentile_disc(0.5)  within group(order by score) over (partition by name) as c from t1;
+select name, percentile_cont(0.5)  within group(order by score) over (partition by name) as c from t1;
+
+select name,cume_dist() over (partition by name order by score) as b, percentile_disc(0.1)  within group(order by score) over (partition by name) as c from t1;
+select name,cume_dist() over (partition by name order by score) as b, percentile_disc(0.2)  within group(order by score) over (partition by name) as c from t1;
+select name,cume_dist() over (partition by name order by score) as b, percentile_disc(0.3)  within group(order by score) over (partition by name) as c from t1;
+select name,cume_dist() over (partition by name order by score) as b, percentile_disc(0.4)  within group(order by score) over (partition by name) as c from t1;
+select name,cume_dist() over (partition by name order by score) as b, percentile_disc(0.5)  within group(order by score) over (partition by name) as c from t1;
+select name,cume_dist() over (partition by name order by score) as b, percentile_disc(0.6)  within group(order by score) over (partition by name) as c from t1;
+select name,cume_dist() over (partition by name order by score) as b, percentile_disc(0.7)  within group(order by score) over (partition by name) as c from t1;
+select name,cume_dist() over (partition by name order by score) as b, percentile_disc(0.8)  within group(order by score) over (partition by name) as c from t1;
+select name,cume_dist() over (partition by name order by score) as b, percentile_disc(0.9)  within group(order by score) over (partition by name) as c from t1;
+select name,cume_dist() over (partition by name order by score) as b, percentile_disc(1)  within group(order by score) over (partition by name) as c from t1;
+
+select median(score) over (partition by name), percentile_cont(0)  within group(order by score) over (partition by name) as c from t1;
+select median(score) over (partition by name), percentile_cont(0.1)  within group(order by score) over (partition by name) as c from t1;
+select median(score) over (partition by name), percentile_cont(0.2)  within group(order by score) over (partition by name) as c from t1;
+select median(score) over (partition by name), percentile_cont(0.3)  within group(order by score) over (partition by name) as c from t1;
+select median(score) over (partition by name), percentile_cont(0.4)  within group(order by score) over (partition by name) as c from t1;
+select median(score) over (partition by name), percentile_cont(0.5)  within group(order by score) over (partition by name) as c from t1;
+select median(score) over (partition by name), percentile_cont(0.6)  within group(order by score) over (partition by name) as c from t1;
+select median(score) over (partition by name), percentile_cont(0.7)  within group(order by score) over (partition by name) as c from t1;
+select median(score) over (partition by name), percentile_cont(0.8)  within group(order by score) over (partition by name) as c from t1;
+select median(score) over (partition by name), percentile_cont(0.9)  within group(order by score) over (partition by name) as c from t1;
+select median(score) over (partition by name), percentile_cont(1)  within group(order by score) over (partition by name) as c from t1;
+drop table t1;

sql/item_windowfunc.cc

@@ -176,7 +176,7 @@ bool Item_window_func::check_result_type_of_order_item()
     Item_result rtype= window_spec->order_list->first->item[0]->cmp_type();
     // TODO (varun) : support date type in percentile_cont function 
     if (rtype != REAL_RESULT && rtype != INT_RESULT &&
-        rtype != DECIMAL_RESULT && rtype != TIME_RESULT 
+        rtype != DECIMAL_RESULT && rtype != TIME_RESULT &&
         window_func()->sum_func() == Item_sum::PERCENTILE_CONT_FUNC)
     {
       my_error(ER_WRONG_TYPE_FOR_PERCENTILE_CONT, MYF(0));