Sql Server functions:

Category Type Function name Description
String ASCII(x) Convert character x to ASCII
String CHAR(x) Convert ASCII x to character
String + String concatenate
String CHARINDEX(search, str[, start]) Find first occurrence of substring search in str, starting from start
String PATINDEX(search, str) Find first occurrence of pattern search in string str
String LOWER(x) Convert x to lowercase
String UPPER(x) Convert x to uppercase
String LTRIM Remove leading blank spaces from x
String RTRIM Remove trailing blank spaces from x
String LTRIM(RTRIM(x)) Remove leading and trailing blanks from x
String REPLICATE Repeat str n times
String SPACE(n)String of n spaces
String STR Convert number to string
String SUBSTRING(str, start, length) Substring from string str, starting from start, length of len
String REPLACE Replace characters (MSSQL by default works case insensitively)
String LEN(x) Length of string x (in characters)
String DATALENGTH(x) Length of string x (in bytes)
String QUOTENAME(x, '''') Quote SQL in string x
String SOUNDEX(x) Soundex index of string x
Conversion CAST (expression AS datatype)
Conversion CONVERT (datatype, expression)
DateTime GETDATE() Get Current Date
DateTime DATEADD (datepart, number, date) Date addition
DateTime DATEDIFF (datepart, start, end) Date subtraction
DateTime DATEDIFF (datepart, start, end) Date difference
DateTime DATENAME (datepart, date) Convert date to string
DateTime DATEPART (datepart, date) Convert date to number
DateTime CAST Convert string to date
DateTime GETUTCDATE() Current Date
DateTime DAY (date)Current day
DateTime MONTH (date)Current month
DateTime YEAR (date) Current year
Aggregate COUNT([DISTINCT] x) Count non-NULL values in x
Aggregate SUM([DISTINCT] x) Sum of x
Aggregate AVG([DISTINCT] x) Average of x
Aggregate MIN(x) Minimum value in x
Aggregate MAX(x) Maximum value in x
Aggregate STDEV(x)
STDEVP(x)
Standard deviation
Aggregate VAR(x)
VARP(x)
Variance
Numeric ABS(x) Absolute value of x
Numeric SIGN(x) Sign of number x
Numeric x % y Modulus (remainder) of x / y
Numeric CEILING(x) Smallest integer >= x
Numeric FLOOR(x) Largest integer <= x
Numeric ROUND(x[, d]) Round x (to precision of d digits)
Numeric SQRT(x) Square root
Numeric EXP(x) Exponent of x (ex)
Numeric POWER(x, y) Power (xy)
Numeric LOG(x) Natural logarithm of x
Numeric LOG10(x) Logarithm, base 10
Numeric RAND(x) Randomize, set seed to x
Numeric RAND() Generate random number
Numeric COALESCE(val1, val2, ...) Return the first non-NULL value from a list of values
Numeric ISNULL(val1, val2)
Numeric NULLIF(val1, val2) Return NULL if two values are equal
Trigonometric ASIN(x) Arc sine
Trigonometric ACOS(x) Arc cosine
Trigonometric ATAN(x) Arc tangent of x
Trigonometric ATN2(x, y) Arc tangent of x and y
Trigonometric SIN(x) Sine
Trigonometric COS(x) Cosine
Trigonometric TAN(x) Tangent
Trigonometric COT(x) Cotangent