99 lines
3.0 KiB
Plaintext
99 lines
3.0 KiB
Plaintext
|
drop table if exists t1;
|
|||
|
|
CREATE TABLE t1 (id CHAR(12) not null, PRIMARY KEY (id));
|
|||
|
|
insert into t1 values ('000000000001'),('000000000002');
|
|||
|
|
explain select * from t1 where id=000000000001;
|
|||
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|||
|
|
1 SIMPLE t1 index PRIMARY PRIMARY 12 NULL 2 Using where; Using index
|
|||
|
|
select * from t1 where id=000000000001;
|
|||
|
|
id
|
|||
|
|
000000000001
|
|||
|
|
delete from t1 where id=000000000002;
|
|||
|
|
select * from t1;
|
|||
|
|
id
|
|||
|
|
000000000001
|
|||
|
|
drop table t1;
|
|||
|
|
SELECT 'a' = 'a ';
|
|||
|
|
'a' = 'a '
|
|||
|
|
1
|
|||
|
|
SELECT 'a\0' < 'a';
|
|||
|
|
'a\0' < 'a'
|
|||
|
|
1
|
|||
|
|
SELECT 'a\0' < 'a ';
|
|||
|
|
'a\0' < 'a '
|
|||
|
|
1
|
|||
|
|
SELECT 'a\t' < 'a';
|
|||
|
|
'a\t' < 'a'
|
|||
|
|
1
|
|||
|
|
SELECT 'a\t' < 'a ';
|
|||
|
|
'a\t' < 'a '
|
|||
|
|
1
|
|||
|
|
CREATE TABLE t1 (a char(10) not null);
|
|||
|
|
INSERT INTO t1 VALUES ('a'),('a\0'),('a\t'),('a ');
|
|||
|
|
SELECT hex(a),STRCMP(a,'a'), STRCMP(a,'a ') FROM t1;
|
|||
|
|
hex(a) STRCMP(a,'a') STRCMP(a,'a ')
|
|||
|
|
61 0 0
|
|||
|
|
6100 -1 -1
|
|||
|
|
6109 -1 -1
|
|||
|
|
61 0 0
|
|||
|
|
DROP TABLE t1;
|
|||
|
|
SELECT CHAR(31) = '', '' = CHAR(31);
|
|||
|
|
CHAR(31) = '' '' = CHAR(31)
|
|||
|
|
0 0
|
|||
|
|
SELECT CHAR(30) = '', '' = CHAR(30);
|
|||
|
|
CHAR(30) = '' '' = CHAR(30)
|
|||
|
|
0 0
|
|||
|
|
create table t1 (a tinyint(1),b binary(1));
|
|||
|
|
insert into t1 values (0x01,0x01);
|
|||
|
|
select * from t1 where a=b;
|
|||
|
|
a b
|
|||
|
|
Warnings:
|
|||
|
|
Warning 1292 Truncated incorrect DOUBLE value: ''
|
|||
|
|
select * from t1 where a=b and b=0x01;
|
|||
|
|
a b
|
|||
|
|
Warnings:
|
|||
|
|
Warning 1292 Truncated incorrect DOUBLE value: ''
|
|||
|
|
drop table if exists t1;
|
|||
|
|
CREATE TABLE t1 (b int(2) zerofill, c int(2) zerofill);
|
|||
|
|
INSERT INTO t1 (b,c) VALUES (1,2), (1,1), (2,2);
|
|||
|
|
SELECT CONCAT(b,c), CONCAT(b,c) = '0101' FROM t1;
|
|||
|
|
CONCAT(b,c) CONCAT(b,c) = '0101'
|
|||
|
|
0102 0
|
|||
|
|
0101 1
|
|||
|
|
0202 0
|
|||
|
|
EXPLAIN EXTENDED SELECT b,c FROM t1 WHERE b = 1 AND CONCAT(b,c) = '0101';
|
|||
|
|
id select_type table type possible_keys key key_len ref rows filtered Extra
|
|||
|
|
1 SIMPLE t1 ALL NULL NULL NULL NULL 3 100.00 Using where
|
|||
|
|
Warnings:
|
|||
|
|
Note 1003 select `test`.`t1`.`b` AS `b`,`test`.`t1`.`c` AS `c` from `test`.`t1` where ((`test`.`t1`.`b` = 1) and (concat('01',`test`.`t1`.`c`) = '0101'))
|
|||
|
|
SELECT b,c FROM t1 WHERE b = 1 AND CONCAT(b,c) = '0101';
|
|||
|
|
b c
|
|||
|
|
01 01
|
|||
|
|
CREATE TABLE t2 (a int);
|
|||
|
|
INSERT INTO t2 VALUES (1),(2);
|
|||
|
|
SELECT a,
|
|||
|
|
(SELECT COUNT(*) FROM t1
|
|||
|
|
WHERE b = t2.a AND CONCAT(b,c) = CONCAT('0',t2.a,'01')) x
|
|||
|
|
FROM t2 ORDER BY a;
|
|||
|
|
a x
|
|||
|
|
1 1
|
|||
|
|
2 0
|
|||
|
|
EXPLAIN EXTENDED
|
|||
|
|
SELECT a,
|
|||
|
|
(SELECT COUNT(*) FROM t1
|
|||
|
|
WHERE b = t2.a AND CONCAT(b,c) = CONCAT('0',t2.a,'01')) x
|
|||
|
|
FROM t2 ORDER BY a;
|
|||
|
|
id select_type table type possible_keys key key_len ref rows filtered Extra
|
|||
|
|
1 PRIMARY t2 ALL NULL NULL NULL NULL 2 100.00 Using filesort
|
|||
|
|
2 DEPENDENT SUBQUERY t1 ALL NULL NULL NULL NULL 3 100.00 Using where
|
|||
|
|
Warnings:
|
|||
|
|
Note 1276 Field or reference 'test.t2.a' of SELECT #2 was resolved in SELECT #1
|
|||
|
|
Note 1276 Field or reference 'test.t2.a' of SELECT #2 was resolved in SELECT #1
|
|||
|
|
Note 1003 select `test`.`t2`.`a` AS `a`,(select count(0) from `test`.`t1` where ((`test`.`t1`.`b` = `test`.`t2`.`a`) and (concat(`test`.`t1`.`b`,`test`.`t1`.`c`) = concat('0',`test`.`t2`.`a`,'01')))) AS `x` from `test`.`t2` order by `test`.`t2`.`a`
|
|||
|
|
DROP TABLE t1,t2;
|
|||
|
|
CREATE TABLE t1 (a TIMESTAMP);
|
|||
|
|
INSERT INTO t1 VALUES (NOW()),(NOW()),(NOW());
|
|||
|
|
SELECT * FROM t1 WHERE a > '2008-01-01' AND a = '0000-00-00';
|
|||
|
|
a
|
|||
|
|
DROP TABLE t1;
|
|||
|
|
End of 5.0 tests
|