mirror of
https://github.com/archlinuxarm/PKGBUILDs.git
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458 lines
14 KiB
Diff
458 lines
14 KiB
Diff
From ce40ccaf24af2fe395f541cb1079256de8727ccd Mon Sep 17 00:00:00 2001
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From: Alexander Barkov <bar@mariadb.org>
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Date: Thu, 28 Jan 2016 13:58:39 +0400
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Subject: [PATCH] MDEV-9181 (NULLIF(count(table.col)), 0) gives wrong result on
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10.1.x Wrapping args[0] and args[2] into an Item_cache for aggregate
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functions.
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---
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mysql-test/r/null.result | 60 ++++++++++++++++++++
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mysql-test/t/null.test | 39 +++++++++++++
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sql/item.h | 45 ++++++++++++---
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sql/item_cmpfunc.cc | 144 +++++++++++++++++++++++++++++++++++++++++++++--
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sql/item_cmpfunc.h | 8 ++-
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5 files changed, 281 insertions(+), 15 deletions(-)
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diff --git a/mysql-test/r/null.result b/mysql-test/r/null.result
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index b4cebac..af24ad4 100644
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--- a/mysql-test/r/null.result
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+++ b/mysql-test/r/null.result
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@@ -1465,5 +1465,65 @@ Warnings:
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Note 1003 select `test`.`t1`.`a` AS `a` from `test`.`t1` where ((`test`.`t1`.`a` = 2020) and ((case when 2020 = 2010 then NULL else `test`.`t1`.`a` end) = concat('2020',rand())))
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DROP TABLE t1;
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#
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+# MDEV-9181 (NULLIF(count(table.col)), 0) gives wrong result on 10.1.x
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+#
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+CREATE TABLE t1 (c1 varchar(50) DEFAULT NULL);
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+INSERT INTO t1 (c1) VALUES ('hello'), ('hello\r\n'), ('hello'),('hello');
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+SELECT NULLIF(COUNT(c1),0) FROM t1;
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+NULLIF(COUNT(c1),0)
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+4
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+SELECT CASE WHEN COUNT(c1)=0 THEN NULL ELSE COUNT(c1) END FROM t1;
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+CASE WHEN COUNT(c1)=0 THEN NULL ELSE COUNT(c1) END
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+4
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+SELECT NULLIF(COUNT(c1)+0,0) AS c1,NULLIF(CAST(COUNT(c1) AS SIGNED),0) AS c2,NULLIF(CONCAT(COUNT(c1)),0) AS c3 FROM t1;
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+c1 c2 c3
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+4 4 4
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+SELECT NULLIF(COUNT(DISTINCT c1),0) FROM t1;
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+NULLIF(COUNT(DISTINCT c1),0)
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+2
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+SELECT CASE WHEN COUNT(DISTINCT c1)=0 THEN NULL ELSE COUNT(DISTINCT c1) END FROM t1;
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+CASE WHEN COUNT(DISTINCT c1)=0 THEN NULL ELSE COUNT(DISTINCT c1) END
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+2
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+DROP TABLE t1;
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+CREATE TABLE t1 (
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+id INT NOT NULL,
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+c1 INT DEFAULT NULL
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+);
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+INSERT INTO t1 VALUES (1,1),(1,2),(2,3),(2,4);
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+SELECT NULLIF(COUNT(c1),0) AS c1,NULLIF(COUNT(c1)+0,0) AS c1_wrapped,CASE WHEN COUNT(c1) IS NULL THEN 0 ELSE COUNT(c1) END AS c1_case FROM t1 GROUP BY id;
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+c1 c1_wrapped c1_case
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+2 2 2
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+2 2 2
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+DROP TABLE t1;
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+CREATE TABLE t1 (a INT);
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+INSERT INTO t1 VALUES (1),(2),(3);
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+SET @a=0;
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+SELECT NULLIF(LAST_VALUE(@a:=@a+1,a),0) FROM t1;
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+NULLIF(LAST_VALUE(@a:=@a+1,a),0)
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+1
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+2
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+3
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+SELECT @a;
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+@a
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+6
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+SET @a=0;
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+SELECT NULLIF(AVG(a),0), NULLIF(AVG(LAST_VALUE(@a:=@a+1,a)),0) FROM t1;
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+NULLIF(AVG(a),0) NULLIF(AVG(LAST_VALUE(@a:=@a+1,a)),0)
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+2.0000 2.0000
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+SELECT @a;
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+@a
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+3
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+EXPLAIN EXTENDED SELECT NULLIF(a,0) FROM t1;
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+id select_type table type possible_keys key key_len ref rows filtered Extra
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+1 SIMPLE t1 ALL NULL NULL NULL NULL 3 100.00
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+Warnings:
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+Note 1003 select nullif(`test`.`t1`.`a`,0) AS `NULLIF(a,0)` from `test`.`t1`
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+EXPLAIN EXTENDED SELECT NULLIF(AVG(a),0) FROM t1;
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+id select_type table type possible_keys key key_len ref rows filtered Extra
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+1 SIMPLE t1 ALL NULL NULL NULL NULL 3 100.00
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+Warnings:
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+Note 1003 select nullif(<cache>(avg(`test`.`t1`.`a`)),0) AS `NULLIF(AVG(a),0)` from `test`.`t1`
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+DROP TABLE t1;
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+#
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# End of 10.1 tests
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#
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diff --git a/mysql-test/t/null.test b/mysql-test/t/null.test
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index 5347a96..b60f11a 100644
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--- a/mysql-test/t/null.test
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+++ b/mysql-test/t/null.test
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@@ -909,6 +909,45 @@ EXPLAIN EXTENDED
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SELECT * FROM t1 WHERE a=2020 AND NULLIF(a,2010)=CONCAT('2020',RAND());
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DROP TABLE t1;
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+--echo #
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+--echo # MDEV-9181 (NULLIF(count(table.col)), 0) gives wrong result on 10.1.x
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+--echo #
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+CREATE TABLE t1 (c1 varchar(50) DEFAULT NULL);
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+INSERT INTO t1 (c1) VALUES ('hello'), ('hello\r\n'), ('hello'),('hello');
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+SELECT NULLIF(COUNT(c1),0) FROM t1;
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+SELECT CASE WHEN COUNT(c1)=0 THEN NULL ELSE COUNT(c1) END FROM t1;
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+SELECT NULLIF(COUNT(c1)+0,0) AS c1,NULLIF(CAST(COUNT(c1) AS SIGNED),0) AS c2,NULLIF(CONCAT(COUNT(c1)),0) AS c3 FROM t1;
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+SELECT NULLIF(COUNT(DISTINCT c1),0) FROM t1;
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+SELECT CASE WHEN COUNT(DISTINCT c1)=0 THEN NULL ELSE COUNT(DISTINCT c1) END FROM t1;
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+DROP TABLE t1;
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+
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+CREATE TABLE t1 (
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+ id INT NOT NULL,
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+ c1 INT DEFAULT NULL
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+);
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+INSERT INTO t1 VALUES (1,1),(1,2),(2,3),(2,4);
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+SELECT NULLIF(COUNT(c1),0) AS c1,NULLIF(COUNT(c1)+0,0) AS c1_wrapped,CASE WHEN COUNT(c1) IS NULL THEN 0 ELSE COUNT(c1) END AS c1_case FROM t1 GROUP BY id;
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+DROP TABLE t1;
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+
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+# Testing with side effects
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+
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+CREATE TABLE t1 (a INT);
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+INSERT INTO t1 VALUES (1),(2),(3);
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+SET @a=0;
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+SELECT NULLIF(LAST_VALUE(@a:=@a+1,a),0) FROM t1;
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+SELECT @a;
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+SET @a=0;
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+SELECT NULLIF(AVG(a),0), NULLIF(AVG(LAST_VALUE(@a:=@a+1,a)),0) FROM t1;
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+SELECT @a;
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+
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+# There should not be cache in here:
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+
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+EXPLAIN EXTENDED SELECT NULLIF(a,0) FROM t1;
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+
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+# But there should be a cache in here:
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+EXPLAIN EXTENDED SELECT NULLIF(AVG(a),0) FROM t1;
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+
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+DROP TABLE t1;
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--echo #
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--echo # End of 10.1 tests
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diff --git a/sql/item.h b/sql/item.h
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index d5b6463..9c57628 100644
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--- a/sql/item.h
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+++ b/sql/item.h
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@@ -3629,6 +3629,11 @@ class Used_tables_and_const_cache
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used_tables_cache|= item->used_tables();
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const_item_cache&= item->const_item();
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}
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+ void used_tables_and_const_cache_update_and_join(Item *item)
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+ {
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+ item->update_used_tables();
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+ used_tables_and_const_cache_join(item);
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+ }
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/*
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Call update_used_tables() for all "argc" items in the array "argv"
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and join with the current cache.
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@@ -3638,10 +3643,7 @@ class Used_tables_and_const_cache
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void used_tables_and_const_cache_update_and_join(uint argc, Item **argv)
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{
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for (uint i=0 ; i < argc ; i++)
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- {
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- argv[i]->update_used_tables();
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- used_tables_and_const_cache_join(argv[i]);
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- }
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+ used_tables_and_const_cache_update_and_join(argv[i]);
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}
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/*
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Call update_used_tables() for all items in the list
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@@ -3654,10 +3656,7 @@ class Used_tables_and_const_cache
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List_iterator_fast<Item> li(list);
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Item *item;
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while ((item=li++))
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- {
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- item->update_used_tables();
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- used_tables_and_const_cache_join(item);
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- }
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+ used_tables_and_const_cache_update_and_join(item);
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}
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};
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@@ -5073,6 +5072,12 @@ class Item_cache: public Item_basic_constant
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return (this->*processor)(arg);
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}
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virtual Item *safe_charset_converter(THD *thd, CHARSET_INFO *tocs);
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+ void split_sum_func2_example(THD *thd, Item **ref_pointer_array,
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+ List<Item> &fields, uint flags)
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+ {
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+ example->split_sum_func2(thd, ref_pointer_array, fields, &example, flags);
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+ }
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+ Item *get_example() const { return example; }
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};
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@@ -5177,6 +5182,30 @@ class Item_cache_str: public Item_cache
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bool cache_value();
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};
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+
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+class Item_cache_str_for_nullif: public Item_cache_str
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+{
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+public:
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+ Item_cache_str_for_nullif(THD *thd, const Item *item)
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+ :Item_cache_str(thd, item)
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+ { }
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+ Item *safe_charset_converter(THD *thd, CHARSET_INFO *tocs)
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+ {
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+ /**
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+ Item_cache_str::safe_charset_converter() returns a new Item_cache
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+ with Item_func_conv_charset installed on "example". The original
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+ Item_cache is not referenced (neither directly nor recursively)
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+ from the result of Item_cache_str::safe_charset_converter().
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+
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+ For NULLIF() purposes we need a different behavior:
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+ we need a new instance of Item_func_conv_charset,
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+ with the original Item_cache referenced in args[0]. See MDEV-9181.
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+ */
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+ return Item::safe_charset_converter(thd, tocs);
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+ }
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+};
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+
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+
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class Item_cache_row: public Item_cache
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{
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Item_cache **values;
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diff --git a/sql/item_cmpfunc.cc b/sql/item_cmpfunc.cc
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index 87be0f9..135c443 100644
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--- a/sql/item_cmpfunc.cc
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+++ b/sql/item_cmpfunc.cc
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@@ -2531,12 +2531,137 @@ bool Item_func_if::date_op(MYSQL_TIME *ltime, uint fuzzydate)
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}
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+void Item_func_nullif::split_sum_func(THD *thd, Item **ref_pointer_array,
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+ List<Item> &fields, uint flags)
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+{
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+ if (m_cache)
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+ {
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+ flags|= SPLIT_SUM_SKIP_REGISTERED; // See Item_func::split_sum_func
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+ m_cache->split_sum_func2_example(thd, ref_pointer_array, fields, flags);
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+ args[1]->split_sum_func2(thd, ref_pointer_array, fields, &args[1], flags);
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+ }
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+ else
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+ {
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+ Item_func::split_sum_func(thd, ref_pointer_array, fields, flags);
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+ }
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+}
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+
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+
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+void Item_func_nullif::update_used_tables()
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+{
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+ if (m_cache)
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+ {
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+ used_tables_and_const_cache_init();
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+ used_tables_and_const_cache_update_and_join(m_cache->get_example());
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+ used_tables_and_const_cache_update_and_join(arg_count, args);
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+ }
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+ else
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+ {
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+ Item_func::update_used_tables();
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+ }
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+}
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+
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+
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+
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void
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Item_func_nullif::fix_length_and_dec()
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{
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if (!args[2]) // Only false if EOM
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return;
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+ DBUG_ASSERT(args[0] == args[2]);
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+ THD *thd= current_thd;
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+ if (args[0]->type() == SUM_FUNC_ITEM)
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+ {
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+ /*
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+ NULLIF(l_expr, r_expr)
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+
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+ is calculated in the way to return a result equal to:
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+
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+ CASE WHEN l_expr = r_expr THEN NULL ELSE r_expr END.
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+
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+ There's nothing special with r_expr, because it's referenced
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+ only by args[1] and nothing else.
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+
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+ l_expr needs a special treatment, as it's referenced by both
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+ args[0] and args[2] initially.
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+
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+ args[0] and args[2] can be replaced:
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+
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+ - to Item_func_conv_charset by character set aggregation routines
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+ - to a constant Item by equal field propagation routines
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+ (in case of Item_field)
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+
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+ For aggregate functions we have to wrap the original args[0]/args[2]
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+ into Item_cache (see MDEV-9181). In this case the Item_cache
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+ instance becomes the subject to character set conversion instead of
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+ the original args[0]/args[2], while the original args[0]/args[2] get
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+ hidden inside the cache.
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+
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+ Some examples of what NULLIF can end up with after argument
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+ substitution (we don't mention args[1] here for simplicity):
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+
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+ 1. l_expr is not an aggragate function:
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+
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+ a. No conversion happened.
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+ args[0] and args[2] were not replaced to something else
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+ (i.e. neither by character set conversion, nor by propagation):
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+
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+ args[0] \
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+ l_expr
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+ args[2] /
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+
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+ b. Conversion of args[0] happened.
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+ args[0] was replaced, e.g. to Item_func_conv_charset:
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+
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+ args[0] > Item_func_conv_charset \
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+ l_expr
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+ args[2] >------------------------/
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+
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+ c. Conversion of args[2] happened:
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+
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+ args[0] >------------------------\
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+ l_expr
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+ args[2] > Item_func_conv_charset /
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+
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+ d. Conversion of both args[0] and args[2] happened
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+ (e.g. by equal field propagation).
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+
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+ args[0] > Item_int
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+ args[2] > Item_int
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+
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+ 2. In case if l_expr is an aggregate function:
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+
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+ a. No conversion happened:
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+
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+ args[0] \
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+ Item_cache > l_expr
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+ args[2] /
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+
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+ b. Conversion of args[0] happened:
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+
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+ args[0] > Item_func_conv_charset \
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+ Item_cache > l_expr
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+ args[2] >------------------------/
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+
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+ c. Conversion of args[2] happened:
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+
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+ args[0] >------------------------\
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+ Item_cache > l_expr
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+ args[2] > Item_func_conv_charset /
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+
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+ d. Conversion of both args[0] and args[2] happened.
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+ (e.g. by equal expression propagation)
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+ TODO: check if it's possible (and add an example query if so).
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+ */
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+ m_cache= args[0]->cmp_type() == STRING_RESULT ?
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+ new (thd->mem_root) Item_cache_str_for_nullif(thd, args[0]) :
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+ Item_cache::get_cache(thd, args[0]);
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+ m_cache->setup(current_thd, args[0]);
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+ m_cache->store(args[0]);
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+ m_cache->set_used_tables(args[0]->used_tables());
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+ args[0]= args[2]= m_cache;
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+ }
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set_handler_by_field_type(args[2]->field_type());
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collation.set(args[2]->collation);
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decimals= args[2]->decimals;
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@@ -2611,6 +2736,13 @@ void Item_func_nullif::print(String *str, enum_query_type query_type)
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}
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+int Item_func_nullif::compare()
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+{
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+ if (m_cache)
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+ m_cache->cache_value();
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+ return cmp.compare();
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+}
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+
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/**
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@note
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Note that we have to evaluate the first argument twice as the compare
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@@ -2626,7 +2758,7 @@ Item_func_nullif::real_op()
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{
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DBUG_ASSERT(fixed == 1);
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double value;
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- if (!cmp.compare())
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+ if (!compare())
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{
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null_value=1;
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return 0.0;
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@@ -2641,7 +2773,7 @@ Item_func_nullif::int_op()
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{
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DBUG_ASSERT(fixed == 1);
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longlong value;
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- if (!cmp.compare())
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+ if (!compare())
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{
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null_value=1;
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return 0;
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@@ -2656,7 +2788,7 @@ Item_func_nullif::str_op(String *str)
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{
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DBUG_ASSERT(fixed == 1);
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String *res;
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- if (!cmp.compare())
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+ if (!compare())
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{
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null_value=1;
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return 0;
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@@ -2672,7 +2804,7 @@ Item_func_nullif::decimal_op(my_decimal * decimal_value)
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{
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DBUG_ASSERT(fixed == 1);
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my_decimal *res;
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- if (!cmp.compare())
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+ if (!compare())
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{
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null_value=1;
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return 0;
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@@ -2687,7 +2819,7 @@ bool
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Item_func_nullif::date_op(MYSQL_TIME *ltime, uint fuzzydate)
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{
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DBUG_ASSERT(fixed == 1);
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- if (!cmp.compare())
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+ if (!compare())
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return (null_value= true);
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return (null_value= args[2]->get_date(ltime, fuzzydate));
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}
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@@ -2696,7 +2828,7 @@ Item_func_nullif::date_op(MYSQL_TIME *ltime, uint fuzzydate)
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bool
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Item_func_nullif::is_null()
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{
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- return (null_value= (!cmp.compare() ? 1 : args[2]->null_value));
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+ return (null_value= (!compare() ? 1 : args[2]->null_value));
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}
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diff --git a/sql/item_cmpfunc.h b/sql/item_cmpfunc.h
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index b7c51cd..16f8a24 100644
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--- a/sql/item_cmpfunc.h
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+++ b/sql/item_cmpfunc.h
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@@ -995,10 +995,13 @@ class Item_func_nullif :public Item_func_hybrid_field_type
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- Item_field::propagate_equal_fields(ANY_SUBST) for the left "a"
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- Item_field::propagate_equal_fields(IDENTITY_SUBST) for the right "a"
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*/
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+ Item_cache *m_cache;
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+ int compare();
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public:
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// Put "a" to args[0] for comparison and to args[2] for the returned value.
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Item_func_nullif(THD *thd, Item *a, Item *b):
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- Item_func_hybrid_field_type(thd, a, b, a)
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+ Item_func_hybrid_field_type(thd, a, b, a),
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+ m_cache(NULL)
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{}
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bool date_op(MYSQL_TIME *ltime, uint fuzzydate);
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double real_op();
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@@ -1009,6 +1012,9 @@ class Item_func_nullif :public Item_func_hybrid_field_type
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uint decimal_precision() const { return args[2]->decimal_precision(); }
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const char *func_name() const { return "nullif"; }
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void print(String *str, enum_query_type query_type);
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+ void split_sum_func(THD *thd, Item **ref_pointer_array, List<Item> &fields,
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+ uint flags);
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+ void update_used_tables();
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table_map not_null_tables() const { return 0; }
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bool is_null();
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Item* propagate_equal_fields(THD *thd, const Context &ctx, COND_EQUAL *cond)
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