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6a04c2a1aa
upon SELECT .. LIMIT 0 The code must differentiate between a SELECT with contradictory WHERE/HAVING and one with LIMIT 0. Also for the latter printed 'Zero limit' instead of 'Impossible where' in the EXPLAIN output.
164 lines
3.6 KiB
Text
164 lines
3.6 KiB
Text
drop table if exists t1;
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create table t1 (a int not null default 0 primary key, b int not null default 0);
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insert into t1 () values ();
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insert into t1 values (1,1),(2,1),(3,1);
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update t1 set a=4 where b=1 limit 1;
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select * from t1;
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a b
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0 0
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4 1
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2 1
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3 1
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update t1 set b=2 where b=1 limit 2;
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select * from t1;
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a b
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0 0
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4 2
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2 2
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3 1
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update t1 set b=4 where b=1;
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select * from t1;
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a b
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0 0
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4 2
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2 2
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3 4
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delete from t1 where b=2 limit 1;
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select * from t1;
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a b
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0 0
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2 2
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3 4
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delete from t1 limit 1;
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select * from t1;
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a b
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2 2
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3 4
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drop table t1;
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create table t1 (i int);
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insert into t1 (i) values(1),(1),(1);
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delete from t1 limit 1;
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update t1 set i=2 limit 1;
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delete from t1 limit 0;
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update t1 set i=3 limit 0;
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select * from t1;
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i
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2
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1
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drop table t1;
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select 0 limit 0;
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0
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CREATE TABLE t1(id int auto_increment primary key, id2 int, index(id2));
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INSERT INTO t1 (id2) values (0),(0),(0);
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DELETE FROM t1 WHERE id=1;
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INSERT INTO t1 SET id2=0;
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SELECT * FROM t1;
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id id2
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4 0
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2 0
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3 0
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DELETE FROM t1 WHERE id2 = 0 ORDER BY id LIMIT 1;
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SELECT * FROM t1;
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id id2
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4 0
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3 0
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DELETE FROM t1 WHERE id2 = 0 ORDER BY id desc LIMIT 1;
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SELECT * FROM t1;
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id id2
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3 0
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DROP TABLE t1;
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create table t1 (a integer);
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insert into t1 values (1);
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select 1 as a from t1 union all select 1 from dual limit 1;
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a
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1
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(select 1 as a from t1) union all (select 1 from dual) limit 1;
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a
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1
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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),(4),(5),(6),(7);
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explain select count(*) c FROM t1 WHERE a > 0 ORDER BY c LIMIT 3;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t1 ALL NULL NULL NULL NULL 7 Using where; Using temporary
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select count(*) c FROM t1 WHERE a > 0 ORDER BY c LIMIT 3;
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c
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7
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explain select sum(a) c FROM t1 WHERE a > 0 ORDER BY c LIMIT 3;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t1 ALL NULL NULL NULL NULL 7 Using where; Using temporary
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select sum(a) c FROM t1 WHERE a > 0 ORDER BY c LIMIT 3;
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c
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28
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drop table t1;
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prepare s from "select 1 limit ?";
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set @a='qwe';
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execute s using @a;
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1
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set @a=-1;
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execute s using @a;
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ERROR HY000: Incorrect arguments to EXECUTE
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prepare s from "select 1 limit 1, ?";
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execute s using @a;
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ERROR HY000: Incorrect arguments to EXECUTE
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prepare s from "select 1 limit ?, ?";
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execute s using @a, @a;
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ERROR HY000: Incorrect arguments to EXECUTE
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set @a=14632475938453979136;
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execute s using @a, @a;
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1
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set @a=-14632475938453979136;
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execute s using @a, @a;
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ERROR HY000: Incorrect arguments to EXECUTE
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End of 5.0 tests
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select 1 as a limit 4294967296,10;
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a
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CREATE TABLE t1 (a int PRIMARY KEY auto_increment);
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INSERT INTO t1 VALUES (),(),(),(),(),(),(),(),(),();
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INSERT INTO t1 VALUES (),(),(),(),(),(),(),(),(),();
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SELECT a FROM t1 ORDER BY a LIMIT 10 OFFSET 1;
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a
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2
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3
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4
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5
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6
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7
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8
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9
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10
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11
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SELECT a FROM t1 ORDER BY a LIMIT 10 OFFSET 10;
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a
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11
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12
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13
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14
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15
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16
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17
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18
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19
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20
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SELECT a FROM t1 ORDER BY a LIMIT 2 OFFSET 14;
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a
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15
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16
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DROP TABLE t1;
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End of 5.1 tests
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#
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# mdev-16235: SELECT over a table with LIMIT 0
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#
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EXPLAIN
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SELECT * FROM mysql.slow_log WHERE sql_text != 'foo' LIMIT 0;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE NULL NULL NULL NULL NULL NULL NULL Zero limit
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SELECT * FROM mysql.slow_log WHERE sql_text != 'foo' LIMIT 0;
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start_time user_host query_time lock_time rows_sent rows_examined db last_insert_id insert_id server_id sql_text
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EXPLAIN
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SELECT * FROM mysql.help_topic WHERE help_category_id != example LIMIT 0;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE NULL NULL NULL NULL NULL NULL NULL Zero limit
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SELECT * FROM mysql.help_topic WHERE help_category_id != example LIMIT 0;
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help_topic_id name help_category_id description example url
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End of 5.5 tests
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