T-SQL Functions
String Functions
LEN
Returns the number of characters of the specified string.
LEN(string_expression)
LEFT
Returns the left part of a string with the specified number of characters.
LEFT(string_expression, number_of_characters)
RIGHT
Returns the right part of a string with the specified number of characters.
RIGHT(string_expression, number_of_characters)
SUBSTRING
Extracts a part of a string.
SUBSTRING(string_expression, start_position, length)
REPLACE
Replaces all occurrences of a substring with another substring.
REPLACE(string_expression, string_to_replace, replacement_string)
UPPER
Converts a string to uppercase.
UPPER(string_expression)
LOWER
Converts a string to lowercase.
LOWER(string_expression)
TRIM
Removes leading, trailing, or both spaces from a string.
TRIM(string_expression)
Numeric Functions
ABS
Returns the absolute value of a number.
ABS(numeric_expression)
CEILING
Returns the smallest integer greater than or equal to a number.
CEILING(numeric_expression)
FLOOR
Returns the largest integer less than or equal to a number.
FLOOR(numeric_expression)
ROUND
Rounds a numeric expression to a specified length or precision.
ROUND(numeric_expression, length[, function])
SQRT
Returns the square root of a number.
SQRT(numeric_expression)
RAND
Returns a random float number between 0 and 1.
RAND([seed])
Date and Time Functions
GETDATE
Returns the current database system timestamp.
GETDATE()
DATEPART
Returns an integer representing the specified part of a date.
DATEPART(datepart, date)
DATENAME
Returns a character string representing the specified part of a date.
DATENAME(datepart, date)
DATEDIFF
Returns the difference between two dates.
DATEDIFF(datepart, startdate, enddate)
DATEADD
Adds a specified time interval to a date.
DATEADD(datepart, number, date)
Aggregate Functions
COUNT
Counts the number of rows.
COUNT(expression)
SUM
Calculates the sum of values.
SUM(expression)
AVG
Calculates the average of values.
AVG(expression)
MIN
Finds the minimum value.
MIN(expression)
MAX
Finds the maximum value.
MAX(expression)
System Functions
DB_NAME
Returns the name of the specified database.
DB_NAME([database_id])
USER_NAME
Returns the user name associated with a user ID.
USER_NAME([user_id])
SCHEMA_NAME
Returns the schema name for a schema ID.
SCHEMA_NAME([schema_id])