DRDS支持常见的操作符函数、流程控制函数、数学函数、字符串函数和时间函数，汇总如下：

操作符函数

函数表达式	函数描述
AND, &&	Logical AND
=	Assign a value (as part of a SET statement, or as part of the SET clause in an UPDATE statement)
BETWEEN … AND …	Check whether a value is within a range of value
BINARY	Cast a string to a binary string
&	Bitwise AND
~	Bitwise inversion
^	Bitwise XOR
DIV	Integer division
/	Division operator
<=>	NULL-safe equal to perator
=	Equal operator
>=	Greater than or equal operator
>	Greater than operator
IS NOT NULL	NOT NULL value test
IS NOT	Test a value against a boolean

流程控制函数

函数表达式	函数描述
CRC32()	Compute a cyclic redundancy check value
DEGREES()	Convert radians to degrees
DIV	Intger division
EXP()	Raise to the power of
FLOOR()	Return the largest integer value not greater than the argument
LN()	Return the natural logarithm of the argument
LOG10()	Return the base-10 logarithm of the argument
LOG2()	Return the base-2 logarithm of the argument
LOG()	Return the natural logarithm of the ﬁrst argument
MOD()	Return the remainder
%, MOD	Modulo operator
PI()	Return the value of pi
POW()	Return the argument raised to the speciﬁed power
POWER()	Return the argument raised to the speciﬁed power
RADIANS()	Return argument converted to radians
RAND()	Return a random ﬂoating-point value
ROUND()	Round the argument
SIGN()	Return the sign of the argument
SIN()	Return the sine of the argument
SQRT()	Return the square root of the argument
TAN()	Return the tangent of the argument
TRUNCATE(	Truncate to speciﬁed number of decimal places

函数表达式	函数描述
ASCII()	Return numeric value of left-most character
BIN()	Return a string containing binary representation of a number
BIT_LENGTH()	Return length of argument in bits
CHAR_LENGTH()	Return number of characters in argument
CHAR()	Return the character for each integer passed
CHARACTER_LENGTH()	Synonym for CHAR_LENGTH()
CONCAT_WS()	Return concatenate with separator
CONCAT()	Return concatenated string
ELT()	Return string at index number
EXPORT_SET()	Return a string such that for every bit set in the value bits, you get an on string and for every unset bit, you get an off string
FIELD()	Return the index (position) of the ﬁrst argument in the subsequent arguments
FIND_IN_SET()	Return the index position of the ﬁrst argument within the second argument
FORMAT()	Return a number formatted to speciﬁed number of decimal places
HEX()	Return a hexadecimal representation of a decimal or string value
INSERT()	Insert a substring at the speciﬁed position up to the speciﬁed number of characters
INSTR()	Return the index of the ﬁrst occurrence of substring
LCASE()	Synonym for LOWER()

函数表达式	函数描述
DATE_ADD()	Add time values (intervals) to a date value
DATE_FORMAT()	Format date as speciﬁed
DATE_SUB()	Subtract a time value (interval) from a date
DATE()	Extract the date part of a date or datetime expression
DATEDIFF()	Subtract two dates
DAY()	Synonym for DAYOFMONTH()
DAYNAME()	Return the name of the weekday
DAYOFMONTH()	Return the day of the month (0-31)
DAYOFWEEK()	Return the weekday index of the argument
DAYOFYEAR()	Return the day of the year (1-366)
EXTRACT()	Extract part of a date
FROM_DAYS()	Convert a day number to a date
FROM_UNIXTIME()	Format UNIX timestamp as a date
GET_FORMAT()	Return a date format string
HOUR()	Extract the hour
LAST_DAY()	Return the last day of the month for the argument
LOCALTIME()	LOCALTIME Synonym for NOW()
LOCALTIMESTAMP, LOCALTIMESTAMP()	Synonym for NOW()
MAKEDATE()	Create a date from the year and day of year
MAKETIME()	Create time from hour, minute, second
MICROSECOND()	Return the microseconds from argument
MINUTE()	Return the minute from the argument