Convert ntile to work with expressions as parameters.

mysql-test/r/win_ntile.result

@@ -357,4 +357,79 @@ pk	a	b	ntile(20) over (partition by b order by pk)
 17	2	20	3
 19	4	20	4
 20	4	20	5
+select pk, a, b,
+ntile(1 + 3) over (partition by b order by pk)
+from t1;
+pk	a	b	ntile(1 + 3) over (partition by b order by pk)
+11	0	10	1
+12	0	10	1
+13	1	10	2
+14	1	10	3
+18	2	10	4
+15	2	20	1
+16	2	20	1
+17	2	20	2
+19	4	20	3
+20	4	20	4
+select pk, a, b,
+ntile((select 4)) over (partition by b order by pk)
+from t1;
+pk	a	b	ntile((select 4)) over (partition by b order by pk)
+11	0	10	1
+12	0	10	1
+13	1	10	2
+14	1	10	3
+18	2	10	4
+15	2	20	1
+16	2	20	1
+17	2	20	2
+19	4	20	3
+20	4	20	4
+select t1.a from t1 where pk = 11;
+a
+0
+select pk, a, b,
+ntile((select a from t1 where pk=11)) over (partition by b order by pk)
+from t1;
+ERROR HY000: Argument of NTILE must be greater than 0
+select t1.a from t1 where pk = 13;
+a
+1
+select pk, a, b,
+ntile((select a from t1 where pk=13)) over (partition by b order by pk)
+from t1;
+pk	a	b	ntile((select a from t1 where pk=13)) over (partition by b order by pk)
+11	0	10	1
+12	0	10	1
+13	1	10	1
+14	1	10	1
+18	2	10	1
+15	2	20	1
+16	2	20	1
+17	2	20	1
+19	4	20	1
+20	4	20	1
+explain
+select pk, a, b,
+ntile((select a from t1 where pk=13)) over (partition by b order by pk)
+from t1;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	10	Using temporary
+2	SUBQUERY	t1	const	PRIMARY	PRIMARY	4	const	1	
+select a from t1;
+a
+0
+0
+1
+1
+2
+2
+2
+2
+4
+4
+select pk, a, b,
+ntile((select a from t1)) over (partition by b order by pk)
+from t1;
+ERROR 21000: Subquery returns more than 1 row
 drop table t1;

mysql-test/t/win_ntile.test

@@ -137,11 +137,35 @@ select pk, a, b,
     ntile(20) over (partition by b order by pk)
 from t1;
 
+select pk, a, b,
+    ntile(1 + 3) over (partition by b order by pk)
+from t1;
 
+select pk, a, b,
+    ntile((select 4)) over (partition by b order by pk)
+from t1;
 
+select t1.a from t1 where pk = 11;
+--error ER_INVALID_NTILE_ARGUMENT
+select pk, a, b,
+    ntile((select a from t1 where pk=11)) over (partition by b order by pk)
+from t1;
 
+select t1.a from t1 where pk = 13;
+select pk, a, b,
+    ntile((select a from t1 where pk=13)) over (partition by b order by pk)
+from t1;
 
+explain
+select pk, a, b,
+    ntile((select a from t1 where pk=13)) over (partition by b order by pk)
+from t1;
 
+select a from t1;
+--error ER_SUBQUERY_NO_1_ROW
+select pk, a, b,
+    ntile((select a from t1)) over (partition by b order by pk)
+from t1;
 
 
 drop table t1;

sql/item_windowfunc.h

@@ -235,7 +235,10 @@ class Item_sum_window_with_row_count : public Item_sum_num
 {
  public:
   Item_sum_window_with_row_count(THD *thd) : Item_sum_num(thd),
-                                             partition_row_count_(0){}
+                                             partition_row_count_(0) {}
+
+  Item_sum_window_with_row_count(THD *thd, Item *arg) :
+    Item_sum_num(thd, arg), partition_row_count_(0) {};
 
   void set_row_count(ulonglong count) { partition_row_count_ = count; }
 
@@ -398,8 +401,9 @@ class Item_sum_cume_dist: public Item_sum_window_with_row_count
 class Item_sum_ntile : public Item_sum_window_with_row_count
 {
  public:
-  Item_sum_ntile(THD* thd, ulong num_quantiles) :
-    Item_sum_window_with_row_count(thd), num_quantiles_(num_quantiles),
+  Item_sum_ntile(THD* thd, Item* num_quantiles_expr) :
+    Item_sum_window_with_row_count(thd, num_quantiles_expr),
+    num_quantiles_expr_(num_quantiles_expr), num_quantiles_(0),
     current_row_count_(0) {};
 
   double val_real()
@@ -451,7 +455,26 @@ class Item_sum_ntile : public Item_sum_window_with_row_count
   enum Item_result result_type () const { return INT_RESULT; }
   enum_field_types field_type() const { return MYSQL_TYPE_LONGLONG; }
 
+  bool fix_fields(THD *thd, Item **ref)
+  {
+    if (Item_sum_window_with_row_count::fix_fields(thd, ref))
+      return true;
+    // TODO-cvicentiu is ref as a parameter here ok?
+    if (!num_quantiles_expr_->fixed)
+      num_quantiles_expr_->fix_fields(thd, ref);
+    longlong expr_value= num_quantiles_expr_->val_int();
+
+    if (expr_value <= 0) {
+      my_error(ER_INVALID_NTILE_ARGUMENT, MYF(0));
+      return true;
+    }
+
+    num_quantiles_= static_cast<ulong>(expr_value);
+    return false;
+  }
+
  private:
+  Item* num_quantiles_expr_;
   ulong num_quantiles_;
   ulong current_row_count_;
 };

sql/sql_yacc.yy

@@ -10541,13 +10541,8 @@ simple_window_func:
               MYSQL_YYABORT;
           }
         |
-          NTILE_SYM '(' int_num ')'
+          NTILE_SYM '(' expr ')'
           {
-            if ($3 <= 0)
-            {
-              my_error(ER_INVALID_NTILE_ARGUMENT, MYF(0));
-              MYSQL_YYABORT;
-            }
             $$= new (thd->mem_root) Item_sum_ntile(thd, $3);
             if ($$ == NULL)
               MYSQL_YYABORT;