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Funzioni di SQL Server


SQL Server dispone di molte funzioni integrate.

Questo riferimento contiene stringhe, numeri, data, conversione e alcune funzioni avanzate in SQL Server.


Funzioni di stringa di 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


Funzioni matematiche/numeriche di SQL Server

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

Funzioni di data di SQL Server

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

Funzioni avanzate di SQL Server

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