From 935b943703da250fe7031541b74a1fcefe851172 Mon Sep 17 00:00:00 2001
From: Mikhail Filimonov <mfilimonov@altinity.com>
Date: Fri, 3 Jul 2020 12:03:30 +0200
Subject: [PATCH] Test for issue #9088

ALTER DELETE unexpectedly deletes NULL rows
---
 .../01358_mutation_delete_null_rows.reference | 20 ++++++++++++++
 .../01358_mutation_delete_null_rows.sql       | 26 +++++++++++++++++++
 2 files changed, 46 insertions(+)
 create mode 100644 tests/queries/0_stateless/01358_mutation_delete_null_rows.reference
 create mode 100644 tests/queries/0_stateless/01358_mutation_delete_null_rows.sql

diff --git a/tests/queries/0_stateless/01358_mutation_delete_null_rows.reference b/tests/queries/0_stateless/01358_mutation_delete_null_rows.reference
new file mode 100644
index 00000000000..126874237b7
--- /dev/null
+++ b/tests/queries/0_stateless/01358_mutation_delete_null_rows.reference
@@ -0,0 +1,20 @@
+--------
+0	1	x=0
+1	0	x<>0
+3	0	x<>0
+\N	\N	x<>0
+--------
+2020-01-01		2	0	leave
+2020-01-02	aaa	0	1	delete
+2020-01-03		2	0	leave
+2020-01-04		2	0	leave
+2020-01-05	\N	2	0	leave
+2020-01-06	aaa	0	1	delete
+2020-01-07	aaa	0	1	delete
+2020-01-08	aaa	\N	\N	leave
+--------
+2020-01-01		2
+2020-01-03		2
+2020-01-04		2
+2020-01-05	\N	2
+2020-01-08	aaa	\N
diff --git a/tests/queries/0_stateless/01358_mutation_delete_null_rows.sql b/tests/queries/0_stateless/01358_mutation_delete_null_rows.sql
new file mode 100644
index 00000000000..cf240c2062b
--- /dev/null
+++ b/tests/queries/0_stateless/01358_mutation_delete_null_rows.sql
@@ -0,0 +1,26 @@
+select '--------';
+SELECT arrayJoin([0, 1, 3, NULL]) AS x,  x = 0,  if(x = 0, 'x=0', 'x<>0') ORDER BY x;
+
+select '--------';
+drop table if exists mutation_delete_null_rows;
+
+CREATE TABLE mutation_delete_null_rows
+(
+    `EventDate` Date,
+    `CounterID` Nullable(String),
+    `UserID` Nullable(UInt32)
+)
+ENGINE = MergeTree()
+ORDER BY EventDate;
+
+INSERT INTO mutation_delete_null_rows VALUES ('2020-01-01', '', 2)('2020-01-02', 'aaa', 0);
+INSERT INTO mutation_delete_null_rows VALUES ('2020-01-03', '', 2)('2020-01-04', '', 2)('2020-01-05', NULL, 2)('2020-01-06', 'aaa', 0)('2020-01-07', 'aaa', 0)('2020-01-08', 'aaa', NULL);
+
+SELECT *,UserID = 0 as UserIDEquals0, if(UserID = 0, 'delete', 'leave') as verdict FROM mutation_delete_null_rows ORDER BY EventDate;
+
+ALTER TABLE mutation_delete_null_rows DELETE WHERE UserID = 0 SETTINGS mutations_sync=1;
+
+select '--------';
+SELECT * FROM mutation_delete_null_rows ORDER BY EventDate;
+
+drop table mutation_delete_null_rows;
\ No newline at end of file