SQL Server Functions : SQL Server functions has many built-in functions. This reference contains the string, numeric, date, conversion, and advanced functions in SQL Server.
SQL Server String Functions
| Function | Description |
| ASCII | Returns the number code that represents the specific character |
| CHAR | Returns the ASCII character based on the number code |
| CHARINDEX | Returns the location of a substring in a string |
| CONCAT | Concatenates two or more strings together |
| Concat with + | Concatenates two or more strings together |
| DATALENGTH | Returns the length of an expression (in bytes) |
| LEFT | Extracts a substring from a string (starting from left) |
| LEN | Returns the length of the specified string |
| LOWER | Converts a string to lower-case |
| LTRIM | Removes leading spaces from a string |
| NCHAR | Returns the Unicode character based on the number code |
| PATINDEX | Returns the location of a pattern in a string |
| REPLACE | Replaces a sequence of characters in a string with another set of characters |
| RIGHT | Extracts a substring from a string (starting from right) |
| RTRIM | Removes trailing spaces from a string |
| SPACE | Returns a string with a specified number of spaces |
| STR | Returns a string representation of a number |
| STUFF | Deletes a sequence of characters from a string and then inserts another sequence of characters into the string, starting at a specified position |
| SUBSTRING | Extracts a substring from a string |
| UPPER | Converts a string to upper-case |
SQL Server Numeric Functions
| Function | Description |
| ABS | Returns the absolute value of a number |
| AVG | Returns the average value of an expression |
| CEILING | Returns the smallest integer value that is greater than or equal to a number |
| COUNT | Returns the count of an expression |
| FLOOR | Returns the largest integer value that is equal to or less than a number |
| MAX | Returns the maximum value of an expression |
| MIN | Returns the minimum value of an expression |
| RAND | Returns a random number or a random number within a range |
| ROUND | Returns a number rounded to a certain number of decimal places |
| SIGN | Returns a value indicating the sign of a number |
| SUM | Returns the summed value of an expression |
SQL Server Date Functions
| Function | Description |
| CURRENT_TIMESTAMP | Returns the current date and time |
| DATEADD | Returns a date after a certain time/date interval has been added |
| DATEDIFF | Returns the difference between two date values, based on the interval specified |
| DATENAME | Returns a specified part of a given date, as a string value |
| DATEPART | Returns a specified part of a given date, as an integer value |
| DAY | Returns the day of the month (from 1 to 31) for a given date |
| GETDATE | Returns the current date and time |
| GETUTCDATE | Returns the current UTC date and time |
| MONTH | Returns the month (from 1 to 12) for a given date |
| YEAR | Returns the year (as a four-digit number) for a given date |
SQL Server Conversion Functions
| Function | Description |
| CAST | Converts an expression from one data type to another |
| CONVERT | Converts an expression from one data type to another |
SQL Server Advanced Functions
| Function | Description |
| COALESCE | Returns the first non-null expression in a list |
| CURRENT_USER | Returns the name of the current user in the SQL Server database |
| ISDATE | Returns 1 if the expression is a valid date, otherwise 0 |
| ISNULL | Lets you return an alternative value when an expression is NULL |
| ISNUMERIC | Returns 1 if the expression is a valid number, otherwise 0 |
| NULLIF | Compares two expressions |
| SESSION_USER | Returns the user name of the current session in the SQL Server database |
| SESSIONPROPERTY | Returns the setting for a specified option of a session |
| SYSTEM_USER | Returns the login name information for the current user in the SQL Server database |
| USER_NAME | Returns the user name in the SQL Server database |