mysql部分函数试用

秒速五厘米 2022-09-25 08:24 162阅读 0赞

mysql> select ASCII("2");  
\+------------+  
| ASCII("2") |  
\+------------+  
| 50 |  
\+------------+  
1 row in set  
  
  
mysql> select BIN(12);  
\+---------+  
| BIN(12) |  
\+---------+  
| 1100 |  
\+---------+  
1 row in set  
  
  
mysql> select BIN(1  
12);  
\+----------+  
| BIN(112) |  
\+----------+  
| 1110000 |  
\+----------+  
1 row in set  
  
  
mysql> select ASCII("a  
");  
\+------------+  
| ASCII("a") |  
\+------------+  
| 97 |  
\+------------+  
1 row in set  
  
  
mysql> select CONV("a",10,2);  
1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'select CONV("a",10,2)' at line 3  
mysql> select CONV("a",16  
,2);  
\+----------------+  
| CONV("a",16,2) |  
\+----------------+  
| 1010 |  
\+----------------+  
1 row in set  
  
  
mysql> select conv(16,10,16);  
\+----------------+  
| conv(16,10,16) |  
\+----------------+  
| 10 |  
\+----------------+  
1 row in set  
  
  
mysql> select conv(16,10,15  
);  
\+----------------+  
| conv(16,10,15) |  
\+----------------+  
| 11 |  
\+----------------+  
1 row in set  
  
  
mysql> select char(97);  
\+----------+  
| char(97) |  
\+----------+  
| a |  
\+----------+  
1 row in set  
  
  
mysql> select concat('my','sql');  
\+--------------------+  
| concat('my','sql') |  
\+--------------------+  
| mysql |  
\+--------------------+  
1 row in set  
  
  
mysql> select left('school',3);  
\+------------------+  
| left('school',3) |  
\+------------------+  
| sch |  
\+------------------+  
1 row in set  
  
  
mysql> select substring('school',3,4  
);  
\+-------------------------+  
| substring('school',3,4) |  
\+-------------------------+  
| hool |  
\+-------------------------+  
1 row in set  
  
  
mysql> select substring('school',3,10  
);  
\+--------------------------+  
| substring('school',3,10) |  
\+--------------------------+  
| hool |  
\+--------------------------+  
1 row in set  
  
  
mysql> select substring('school',3,2  
);  
\+-------------------------+  
| substring('school',3,2) |  
\+-------------------------+  
| ho |  
\+-------------------------+  
1 row in set  
  
  
mysql> select trim('scsssv ho ol'  
);  
\+------------------------+  
| trim('scsssv ho ol') |  
\+------------------------+  
| scsssv ho ol |  
\+------------------------+  
1 row in set  
  
  
mysql> select l  
trim(' scsssv ho ol');  
\+----------------------------+  
| ltrim(' scsssv ho ol') |  
\+----------------------------+  
| scsssv ho ol |  
\+----------------------------+  
1 row in set  
  
  
mysql> select r  
trim(' scsssv ho ol ');  
\+-------------------------------------+  
| rtrim(' scsssv ho ol ') |  
\+-------------------------------------+  
| scsssv ho ol |  
\+-------------------------------------+  
1 row in set  
  
  
mysql> select  
trim(' scsssv ho ol ');  
\+------------------------------------+  
| trim(' scsssv ho ol ') |  
\+------------------------------------+  
| scsssv ho ol |  
\+------------------------------------+  
1 row in set  
  
  
mysql> select soundex("schul");  
1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'select soundex("schul")' at line 3  
mysql> select soundex("schoo  
l");  
\+-------------------+  
| soundex("school") |  
\+-------------------+  
| S400 |  
\+-------------------+  
1 row in set  
  
  
mysql> select soundex("hello  
");  
\+------------------+  
| soundex("hello") |  
\+------------------+  
| H400 |  
\+------------------+  
1 row in set  
  
  
mysql> select space(' ');  
\+--------------+  
| space(' ') |  
\+--------------+  
| |  
\+--------------+  
1 row in set  
  
  
mysql> select reverse('sadfaf asfdawwww');  
\+-----------------------------+  
| reverse('sadfaf asfdawwww') |  
\+-----------------------------+  
| wwwwadfsa fafdas |  
\+-----------------------------+  
1 row in set  
  
  
mysql> select replace('ouousfsf','sf','ssff');  
\+---------------------------------+  
| replace('ouousfsf','sf','ssff') |  
\+---------------------------------+  
| ououssffssff |  
\+---------------------------------+  
1 row in set  
  
  
mysql> select export\_set(23,'23','Y','YWE','ss');  
\+------------------------------------+  
| export\_set(23,'23','Y','YWE','ss') |  
\+------------------------------------+  
| |  
\+------------------------------------+  
1 row in set  
  
  
mysql> select export\_set(23,'23','Y','YWE','ss');  
\+------------------------------------+  
| export\_set(23,'23','Y','YWE','ss') |  
\+------------------------------------+  
| |  
\+------------------------------------+  
1 row in set  
  
  
mysql> select ucase  
(23,'23','Y','YWE','ss');  
1582 - Incorrect parameter count in the call to native function 'ucase'  
1582 - Incorrect parameter count in the call to native function 'ucase'  
\->  
\-> select ucase('Hey');  
1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '1582 - Incorrect parameter count in the call to native function 'ucase'  
  
  
sele' at line 1  
mysql> ;  
1065 - Query was empty  
mysql> select UCASE  
('Hey');  
\+--------------+  
| UCASE('Hey') |  
\+--------------+  
| HEY |  
\+--------------+  
1 row in set  
  
  
mysql> select (select UCASE('ucase  
'))('Hey');  
1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '('Hey')' at line 1  
1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '('Hey')' at line 1  
1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '1064 - You have an error in your SQL syntax' at line 1  
\->  
\-> select hour('8:00:00');  
1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'the manual that corresponds to your MySQL server version for the right syntax to' at line 1  
mysql> select HOUR  
('8:00:00');  
\+-----------------+  
| HOUR('8:00:00') |  
\+-----------------+  
| 8 |  
\+-----------------+  
1 row in set  
  
  
mysql> select HOUR('  
11:00:00');  
\+------------------+  
| HOUR('11:00:00') |  
\+------------------+  
| 11 |  
\+------------------+  
1 row in set  
  
  
mysql> select curdate();  
\+------------+  
| curdate() |  
\+------------+  
| 2016-08-17 |  
\+------------+  
1 row in set  
  
  
mysql> select curtime  
();  
\+-----------+  
| curtime() |  
\+-----------+  
| 15:15:02 |  
\+-----------+  
1 row in set  
  
  
mysql> select concat(select curtime(),select curdate());  
1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'select curtime(),select curdate())' at line 1  
mysql>  
mysql>  
mysql> select maketime(2016,220);  
1582 - Incorrect parameter count in the call to native function 'maketime'  
mysql> select MAKETIME  
(2016,220);  
1582 - Incorrect parameter count in the call to native function 'MAKETIME'  
1582 - Incorrect parameter count in the call to native function 'MAKETIME'  
\-> select time(8:22:22);  
1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '1582 - Incorrect parameter count in the call to native function 'MAKETIME'  
  
  
s' at line 1  
mysql>  
mysql>  
mysql>  
mysql> select Now();  
\+---------------------+  
| Now() |  
\+---------------------+  
| 2016-08-17 15:18:07 |  
\+---------------------+  
1 row in set  
  
  
mysql> select TIMESTAMP();  
1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ')' at line 1  
mysql> select TIMESTAMP(23  
);  
\+---------------+  
| TIMESTAMP(23) |  
\+---------------+  
| NULL |  
\+---------------+  
1 row in set  
  
  
mysql> select SLEEP  
(3);  
\+----------+  
| SLEEP(3) |  
\+----------+  
| 0 |  
\+----------+  
1 row in set  
  
  
mysql> select UUID  
();  
\+--------------------------------------+  
| UUID() |  
\+--------------------------------------+  
| 10d3ad27-644b-11e6-bee7-507b9d17ef78 |  
\+--------------------------------------+  
1 row in set  
  
  
mysql> select UUID();  
\+--------------------------------------+  
| UUID() |  
\+--------------------------------------+  
| 134b4482-644b-11e6-bee7-507b9d17ef78 |  
\+--------------------------------------+  
1 row in set