MDEV-15204: lag/lead function order list mandatory

MariaDB · Aug 25, 2018 · 2a361eb · 2a361eb
1 parent c826b6b
commit 2a361eb
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Showing 5 changed files with 30 additions and 4 deletions.
diff --git a/mysql-test/r/win.result b/mysql-test/r/win.result
@@ -3219,8 +3219,8 @@ DROP TABLE fv_test, fv_result;
 #
 CREATE TABLE t1 (a int);
 INSERT INTO t1 VALUES (0),(1),(2);
-SELECT LEAD(a) OVER (PARTITION BY a) as lead,
-a AND LEAD(a) OVER (PARTITION BY a) AS a_and_lead_part
+SELECT LEAD(a) OVER (PARTITION BY a ORDER BY a) as lead,
+a AND LEAD(a) OVER (PARTITION BY a ORDER BY a) AS a_and_lead_part
 FROM t1;
 lead	a_and_lead_part
 NULL	0

diff --git a/mysql-test/r/win_lead_lag.result b/mysql-test/r/win_lead_lag.result
@@ -226,4 +226,15 @@ pk	a	b	a+b	lag(a + b) over (partition by a order by pk) + pk
 9	2	2	4	12
 10	2	0	2	14
 11	2	10	12	13
+#
+# MDEV-15204 - LAG function doesn't require ORDER BY in OVER clause
+#
+select pk,
+lag(pk, 1) over ()
+from t1;
+ERROR HY000: No order list in window specification for 'lag'
+select pk,
+lead(pk, 1) over ()
+from t1;
+ERROR HY000: No order list in window specification for 'lead'
 drop table t1;
diff --git a/mysql-test/t/win.test b/mysql-test/t/win.test
@@ -2000,8 +2000,8 @@ DROP TABLE fv_test, fv_result;
 
 CREATE TABLE t1 (a int);
 INSERT INTO t1 VALUES (0),(1),(2);
-SELECT LEAD(a) OVER (PARTITION BY a) as lead,
-       a AND LEAD(a) OVER (PARTITION BY a) AS a_and_lead_part
+SELECT LEAD(a) OVER (PARTITION BY a ORDER BY a) as lead,
+       a AND LEAD(a) OVER (PARTITION BY a ORDER BY a) AS a_and_lead_part
 FROM t1;
 
 SELECT a OR LEAD(a) OVER (ORDER BY a) AS a_or_lead_order

diff --git a/mysql-test/t/win_lead_lag.test b/mysql-test/t/win_lead_lag.test
@@ -107,4 +107,17 @@ select pk, a, b, a+b,
 from t1
 order by pk asc;
 
+--echo #
+--echo # MDEV-15204 - LAG function doesn't require ORDER BY in OVER clause
+--echo #
+--error ER_NO_ORDER_LIST_IN_WINDOW_SPEC
+select pk,
+       lag(pk, 1) over ()
+from t1;
+
+--error ER_NO_ORDER_LIST_IN_WINDOW_SPEC
+select pk,
+       lead(pk, 1) over ()
+from t1;
+
 drop table t1;
diff --git a/sql/item_windowfunc.h b/sql/item_windowfunc.h
@@ -792,6 +792,8 @@ class Item_window_func : public Item_func_or_sum
     case Item_sum::DENSE_RANK_FUNC:
     case Item_sum::PERCENT_RANK_FUNC:
     case Item_sum::CUME_DIST_FUNC:
+    case Item_sum::LAG_FUNC:
+    case Item_sum::LEAD_FUNC:
       return true;
     default: 
       return false;