SQL Server có nhiều chức năng tích hợp sẵn.
Tham chiếu này chứa chuỗi, số, ngày tháng, chuyển đổi và một số hàm nâng cao trong SQL Server.
| Function |
Description |
| ASCII |
Returns the ASCII value for the specific character |
| CHAR |
Returns the character based on the ASCII code |
| CHARINDEX |
Returns the position of a substring in a string |
| CONCAT |
Adds two or more strings together |
| Concat with + |
Adds two or more strings together |
| CONCAT_WS |
Adds two or more strings together with a separator |
| DATALENGTH |
Returns the number of bytes used to represent an expression |
| DIFFERENCE |
Compares two SOUNDEX values, and returns an integer value |
| FORMAT |
Formats a value with the specified format |
| LEFT |
Extracts a number of characters from a string (starting from left) |
| LEN |
Returns the length of a 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 position of a pattern in a string |
| QUOTENAME |
Returns a Unicode string with delimiters added to make the string
a valid SQL Server delimited identifier |
| REPLACE |
Replaces all occurrences of a substring within a string, with a new
substring |
| REPLICATE |
Repeats a string a specified number of times |
| REVERSE |
Reverses a string and returns the result |
| RIGHT |
Extracts a number of characters from a string (starting from right) |
| RTRIM |
Removes trailing spaces from a string |
| SOUNDEX |
Returns a four-character code to evaluate the similarity of two strings |
| SPACE |
Returns a string of the specified number of space characters |
| STR |
Returns a number as string |
| STUFF |
Deletes a part of a string and then inserts another part into the string,
starting at a specified position |
| SUBSTRING |
Extracts some characters from a string |
| TRANSLATE |
Returns the string from the first argument after the characters specified in
the second argument are translated into the characters specified in the third
argument. |
| TRIM |
Removes leading and trailing spaces (or other specified characters) from a string |
| UNICODE |
Returns the Unicode value for the first
character of the input expression |
| UPPER |
Converts a string to upper-case |
| Function |
Description |
| ABS |
Returns the absolute value of a number |
| ACOS |
Returns the arc cosine of a number |
| ASIN |
Returns the arc sine of a number |
| ATAN |
Returns the arc tangent of a number |
| ATN2 |
Returns the arc tangent of two numbers |
| AVG |
Returns the average value of an expression |
| CEILING |
Returns the smallest integer value that is >= a number |
| COUNT |
Returns the number of records returned by a select query |
| COS |
Returns the cosine of a number |
| COT |
Returns the cotangent of a number |
| DEGREES |
Converts a value in radians to degrees |
| EXP |
Returns e raised to the power of a specified number |
| FLOOR |
Returns the largest integer value that is <= to a number |
| LOG |
Returns the natural logarithm of a number, or the logarithm of a number to a
specified base |
| LOG10 |
Returns the natural logarithm of a number to base 10 |
| MAX |
Returns the maximum value in a set of values |
| MIN |
Returns the minimum value in a set of values |
| PI |
Returns the value of PI |
| POWER |
Returns the value of a number raised to the power of another number |
| RADIANS |
Converts a degree value into radians |
| RAND |
Returns a random number |
| ROUND |
Rounds a number to a specified number of decimal places |
| SIGN |
Returns the sign of a number |
| SIN |
Returns the sine of a number |
| SQRT |
Returns the square root of a number |
| SQUARE |
Returns the square of a number |
| SUM |
Calculates the sum of a set of values |
| TAN |
Returns the tangent of a number |
| Function |
Description |
| CURRENT_TIMESTAMP |
Returns the current date and time |
| DATEADD |
Adds a time/date interval to a date and then returns the date |
| DATEDIFF |
Returns the difference between two dates |
| DATEFROMPARTS |
Returns a date from the specified parts (year, month, and day values) |
| DATENAME |
Returns a specified part of a date (as string) |
| DATEPART |
Returns a specified part of a date (as integer) |
| DAY |
Returns the day of the month for a specified date |
| GETDATE |
Returns the current database system date and time |
| GETUTCDATE |
Returns the current database system UTC date and time |
| ISDATE |
Checks an expression and returns 1 if it is a valid date, otherwise 0 |
| MONTH |
Returns the month part for a specified date (a number from 1 to 12) |
| SYSDATETIME |
Returns the date and time of the SQL Server |
| YEAR |
Returns the year part for a specified date |
| Function |
Description |
| CAST |
Converts a value (of any type) into a specified datatype |
| COALESCE |
Returns the first non-null value in a list |
| CONVERT |
Converts a value (of any type) into a specified datatype |
| CURRENT_USER |
Returns the name of the current user in the SQL Server database |
| IIF |
Returns a value if a condition is TRUE, or another value if a condition is FALSE |
| ISNULL |
Return a specified value if the expression is NULL, otherwise return the
expression |
| ISNUMERIC |
Tests whether an expression is numeric |
| NULLIF |
Returns NULL if two expressions are equal |
| SESSION_USER |
Returns the name of the current user in the SQL Server database |
| SESSIONPROPERTY |
Returns the session settings for a specified option |
| SYSTEM_USER |
Returns the login name for the current user |
| USER_NAME |
Returns the database user name based on the specified id |
