ODBC Scalar Functions (Transact-SQL)

Artikkeli
05/23/2023

Applies to: SQL Server Azure SQL Database Azure SQL Managed Instance Azure Synapse Analytics Analytics Platform System (PDW) SQL analytics endpoint in Microsoft Fabric Warehouse in Microsoft Fabric

You can use ODBC Scalar Functions in Transact-SQL statements. These statements are interpreted by SQL Server. They can be used in stored procedures and user-defined functions. These include string, numeric, time, date, interval, and system functions.

Usage

SELECT {fn <function_name> [ (<argument>,....n) ] }

Functions

The following tables list ODBC scalar functions that aren't duplicated in Transact-SQL.

String Functions

Function	Description
BIT_LENGTH( string_exp ) (ODBC 3.0)	Returns the length in bits of the string expression. Returns the internal size of the given data type, without converting string_exp to string.
CONCAT( string_exp1,string_exp2) (ODBC 1.0)	Returns a character string that is the result of concatenating string_exp2 to string_exp1. The resulting string is DBMS-dependent. For example, if the column represented by string_exp1 contained a NULL value, DB2 would return NULL but SQL Server would return the non-NULL string.
OCTET_LENGTH( string_exp ) (ODBC 3.0)	Returns the length in bytes of the string expression. The result is the smallest integer not less than the number of bits divided by 8. Returns the internal size of the given data type, without converting string_exp to string.

Numeric Function

Function	Description
TRUNCATE( numeric_exp, integer_exp) (ODBC 2.0)	Returns numeric_exp truncated to integer_exp positions right of the decimal point. If integer_exp is negative, numeric_exp is truncated to \|integer_exp\| positions to the left of the decimal point.

Time, Date, and Interval Functions

Function	Description
CURRENT_DATE( ) (ODBC 3.0)	Returns the current date.
CURDATE( ) (ODBC 3.0)	Returns the current date.
CURRENT_TIME`[( time-precision )]` (ODBC 3.0)	Returns the current local time. The time-precision argument determines the seconds precision of the returned value
CURTIME() (ODBC 3.0)	Returns the current local time.
DAYNAME( date_exp ) (ODBC 2.0)	Returns a character string that contains the data-source-specific name of the day for the day part of date_exp. For example, the name is Sunday through Saturday or Sun. through Sat. for a data source that uses English. The name is Sonntag through Samstag for a data source that uses German.
DAYOFMONTH( date_exp ) (ODBC 1.0)	Returns the day of the month, based on the month field in date_exp, as an integer. The return value is in the range of 1-31.
DAYOFWEEK( date_exp ) (ODBC 1.0)	Returns the day of the week based on the week field in date_exp as an integer. The return value is in the range of 1-7, where 1 represents Sunday.
HOUR( time_exp ) (ODBC 1.0)	Returns the hour, based on the hour field in time_exp, as an integer value in the range of 0-23.
MINUTE( time_exp ) (ODBC 1.0)	Returns the minute, based on the minute field in time_exp, as an integer value in the range of 0-59.
SECOND( time_exp ) (ODBC 1.0)	Returns the second, based on the second field in time_exp, as an integer value in the range of 0-59.
MONTHNAME( date_exp ) (ODBC 2.0)	Returns a character string that contains the data-source-specific name of the month for the month part of date_exp. For example, the name is January through December or Jan. through Dec. for a data source that uses English. The name is Januar through Dezember for a data source that uses German.
QUARTER( date_exp ) (ODBC 1.0)	Returns the quarter in date_exp as an integer value in the range of 1-4, where 1 represents January 1 through March 31.
WEEK( date_exp ) (ODBC 1.0)	Returns the week of the year, based on the week field in date_exp, as an integer value in the range of 1-53.

Examples

A. Using an ODBC function in a stored procedure

The following example uses an ODBC function in a stored procedure:

CREATE PROCEDURE dbo.ODBCprocedure  
(  
    @string_exp NVARCHAR(4000)  
)  
AS  
SELECT {fn OCTET_LENGTH( @string_exp )};

B. Using an ODBC Function in a user-defined function

The following example uses an ODBC function in a user-defined function:

CREATE FUNCTION dbo.ODBCudf  
(  
    @string_exp NVARCHAR(4000)  
)  
RETURNS INT  
AS  
BEGIN  
DECLARE @len INT  
SET @len = (SELECT {fn OCTET_LENGTH( @string_exp )})  
RETURN(@len)  
END ;  
GO
SELECT dbo.ODBCudf('Returns the length.');  
--Returns 38

Note

Microsoft Fabric does support ODBC scalar functions, but does not currently support user-defined functions that return values, as shown in Example B.

C. Using an ODBC functions in SELECT statements

The following SELECT statements use ODBC functions:

DECLARE @string_exp NVARCHAR(4000) = 'Returns the length.';  
SELECT {fn BIT_LENGTH( @string_exp )};  
-- Returns 304  
SELECT {fn OCTET_LENGTH( @string_exp )};  
-- Returns 38  
  
SELECT {fn CONCAT( 'CONCAT ','returns a character string')};  
-- Returns CONCAT returns a character string  
SELECT {fn TRUNCATE( 100.123456, 4)};  
-- Returns 100.123400  
SELECT {fn CURRENT_DATE( )};  
-- Returns 2007-04-20  
SELECT {fn CURRENT_TIME(6)};  
-- Returns 10:27:11.973000  
  
DECLARE @date_exp NVARCHAR(30) = '2007-04-21 01:01:01.1234567';  
SELECT {fn DAYNAME( @date_exp )};  
-- Returns Saturday  
SELECT {fn DAYOFMONTH( @date_exp )};  
-- Returns 21  
SELECT {fn DAYOFWEEK( @date_exp )};  
-- Returns 7  
SELECT {fn HOUR( @date_exp)};  
-- Returns 1   
SELECT {fn MINUTE( @date_exp )};  
-- Returns 1  
SELECT {fn SECOND( @date_exp )};  
-- Returns 1  
SELECT {fn MONTHNAME( @date_exp )};  
-- Returns April  
SELECT {fn QUARTER( @date_exp )};  
-- Returns 2  
SELECT {fn WEEK( @date_exp )};  
-- Returns 16

Examples: Azure Synapse Analytics and Analytics Platform System (PDW)

D. Using an ODBC function in a stored procedure