SQL的一切常用函数展示

练习了一下，

用时再慢慢看吧。

SHOW WARNINGS;

SELECT quote(text_fld) FROM string_tbl;

), 'n');

SELECT ASCII('ö');

SELECT LENGTH(char_fld) char_length FROM string_tbl;

SELECT POSITION('is' IN vchar_fld) FROM string_tbl;

 )   ));

SELECT MOD(10,4);

　　

,) kilobyte, POW(,) megabyte,
    ,) gigabyte, POW(,) terabyte;

), ), );

SELECT account_id, SIGN(avail_balance), ABS(avail_balance)
    -> FROM account;

SELECT @@global.time_zone, @@session.time_zone;

SELECT CAST('2008-09-17 15:30:00' AS DATETIME);

SELECT CAST('2008-09-17' AS DATE) date_field,
    -> CAST('108:17:57' AS TIME) time_field;

SELECT CURRENT_DATE(), CURRENT_TIME(), CURRENT_TIMESTAMP();

 DAY);

SELECT LAST_DAY('2008-09-17');

SELECT DAYNAME('2008-09-18');

SELECT EXTRACT(YEAR FROM '2008-09-18 22:19:05');

SELECT DATEDIFF('2009-09-03', '2009-06-24');

' AS SIGNED INTEGER);

SELECT CAST('999ABC111' AS UNSIGNED INTEGER);