mysql存储过程基本函数
[@more@]字符集(str)//返回字串字符集
CONCAT (string2相等,……])//连接字串
INSTR (string ,substring )//返回substring首次在string中出现的位置,不存在返回0
LCASE (string2 )//转换成小写
LEFT (string2 ,length )//从string2中的左边起取length个字符
LENGTH (string )//string长度
LOAD_FILE (file_name )//从文件读取内容
LOCATE (substring , string [,start_position ] ) 同INSTR,但可指定开始位置
LPAD (string2 ,length ,pad )//重复用pad加在string开头,直到字串长度为length
LTRIM (string2 )//去除前端空格
REPEAT (string2 ,count )//重复count次
REPLACE (str ,search_str ,replace_str )//在str中用replace_str替换search_str
RPAD (string2 ,length ,pad)//在str后用pad补充,直到长度为length
RTRIM (string2 )//去除后端空格
STRCMP (string1 ,string2 )//逐字符比较两字串大小,
SUBSTRING (str , position [,length ])//从str的position开始,取length个字符,
，即参数position必须大于等于1
mysql> select substring('abcd',0,2);
+-----------------------+
| substring('abcd',0,2) |
+-----------------------+
| |
+-----------------------+
1 row in set (0.00 sec)mysql> select substring('abcd',1,2);
+-----------------------+
| substring('abcd',1,2) |
+-----------------------+
| ab |
+-----------------------+
1 row in set (0.02 sec)
TRIM([[BOTH|LEADING|TRAILING] [padding] FROM]string2)//去除指定位置的指定字符
UCASE (string2 )//转换成大写
RIGHT(string2,length)//取string2最后length个字符
SPACE(count)//生成count个空格
ABS (number2 )//绝对值
BIN (decimal_number )//十进制转二进制
CEILING (number2 )//向上取整
CONV(number2,from_base,to_base)//进制转换
FLOOR (number2 )//向下取整
FORMAT (number,decimal_places )//保留小数位数
HEX (DecimalNumber )//转十六进制
注：HEX()中可传入字符串，则返回其ASC-11码，如HEX('DEF')返回4142143
也可以传入十进制整数，返回其十六进制编码，如HEX(25)返回19
LEAST (number , number2 [,..])//求最小值
MOD (numerator ,denominator )//求余
POWER (number ,power )//求指数
RAND([seed])//随机数
ROUND (number [,decimals ])//四舍五入,decimals为小数位数]
注：返回类型并非均为整数，如：
(1)默认变为整形值
mysql> select round(1.23);
+-------------+
| round(1.23) |
+-------------+
| 1 |
+-------------+
1 row in set (0.00 sec)
mysql> select round(1.56);
+-------------+
| round(1.56) |
+-------------+
| 2 |
+-------------+
1 row in set (0.00 sec)
mysql> select round(1.567,2);
+----------------+
| round(1.567,2) |
+----------------+
| 1.57 |
+----------------+
1 row in set (0.00 sec)
SIGN (number2 )//返回符号,正负或0
SQRT(number2)//开平方
ADDTIME (date2 ,time_interval )//将time_interval加到date2
CONVERT_TZ (datetime2 ,fromTZ ,toTZ )//转换时区
CURRENT_DATE ( )//当前日期
CURRENT_TIME ( )//当前时间
CURRENT_TIMESTAMP ( )//当前时间戳
DATE (datetime )//返回datetime的日期部分
DATE_ADD (date2 , INTERVAL d_value d_type )//在date2中加上日期或时间
DATE_FORMAT (datetime ,FormatCodes )//使用formatcodes格式显示datetime
DATE_SUB (date2 , INTERVAL d_value d_type )//在date2上减去一个时间
DATEDIFF (date1 ,date2 )//两个日期差
DAY (date )//返回日期的天
DAYNAME (date )//英文星期
DAYOFWEEK (date )//星期(1-7) ,1为星期天
DAYOFYEAR (date )//一年中的第几天
EXTRACT (interval_name FROM date )//从date中提取日期的指定部分
MAKEDATE (year ,day )//给出年及年中的第几天,生成日期串
MAKETIME (hour ,minute ,second )//生成时间串
MONTHNAME (date )//英文月份名
NOW ( )//当前时间
SEC_TO_TIME (seconds )//秒数转成时间
STR_TO_DATE (string ,format )//字串转成时间,以format格式显示
TIMEDIFF (datetime1 ,datetime2 )//两个时间差
TIME_TO_SEC (time )//时间转秒数]
WEEK (date_time [,start_of_week ])//第几周
YEAR (datetime )//年份
DAYOFMONTH(datetime)//月的第几天
HOUR(datetime)//小时
LAST_DAY(date)//date的月的最后日期
MICROSECOND(datetime)//微秒
MONTH(datetime)//月
MINUTE(datetime)//分
附:可用在INTERVAL中的类型
DAY ,DAY_HOUR ,DAY_MINUTE ,DAY_SECOND ,HOUR ,HOUR_MINUTE ,HOUR_SECOND ,MINUTE ,MINUTE_SECOND,MONTH ,SECOND ,YEAR
