Scalar Functions

ODBC Driver for Teradata® User Guide

brand
Teradata Tools and Utilities
prodname
ODBC Driver for Teradata
vrm_release
16.20
category
User Guide
featnum
B035-2526-108K

The Teradata Database supports a number of ODBC scalar functions, with additional scalar functions being added incrementally in new database releases. Refer to the Teradata Database Functions, Operators, Expressions and Predicates User Guide (B035-1445) for the list of the currently supported scalar functions by the Teradata Database.

When a client queries a scalar function using a function escape sequence (using the ‘{fn scalar-function}’ syntax, for example, ‘SELECT {fn MOD(x, y) }’), the ODBC Driver will determine whether the connected database supports the scalar function. If so, the ODBC Driver will send the query directly to the database (e.g., “SELECT MOD(x, y)”); if not, the driver will transform the user query to a query that the connected database supports (e.g., “SELECT((x) MOD (y))”).

A client may send a scalar function query without the function escape sequence, for example, “SELECT MOD(x, y)”. In this case, the ODBC Driver will send the client query to the database as is without performing any kind of checks or transformation. This query will succeed if the connected database supports the scalar function, it will fail otherwise. (For the MOD function, it is supported by the 16.20 Feature Update 1 Database, but not the 15.10 Database, for example.)

The following table details a few examples exhibiting the above described behavior.

Statement Text SQL Generated by the ODBC Driver (i.e., SQLNativeSql ) Teradata Database 16.20 Feature Update 1 Teradata Database 15.10
SELECT {fn BIT_LENGTH('Teradata')}
SELECT(Octet_Length('Teradata')*8)
Succeeds Succeeds
SELECT BIT_LENGTH('Teradata')
SELECT BIT_LENGTH('Teradata')
Succeeds Fails
SELECT {fn DAYOFYEAR('2018-02-24') }
SELECT (((('2018-02-24')(DATE))-(((('2018-02-24')(DATE))/10000*10000+0101(DATE)))) + 1(TITLE 'DayOfYear()'))
Succeeds Succeeds
SELECT DAYOFYEAR('2018-02-24')
SELECT DAYOFYEAR('2018-02-24')
Fails Fails

The following functions were updated in the Teradata Database to support the ODBC Driver-accepted syntax.

Function Call Change Teradata Database Version Implemented
CURRENT_DATE() Can be called with or without parenthesis. 16.20 Feature Update 1
LENGTH(s) Can also support numeric expressions. 16.20 Feature Update 1
LTRIM(s) Can also operate on numeric expressions. 16.20 Feature Update 1
RTRIM(s) Can also operate on numeric expressions. 16.20 Feature Update 1
SUBSTRING(s,n1[,n2]) New syntax in Teradata mode 16.20 Feature Update 1

The following functions are now supported in Teradata Database version 16.20 Feature Update 1.

Function Call Purpose
BIT_LENGTH(s) Returns the length in bits of the specified string.
CONCAT(s1,s2[,...sn]) Concatenates two or more parameter values into a single string.
CURDATE() Returns the current date.
CURTIME() Returns the current local time.
DAYOFMONTH(e) Returns the number of days from the beginning of the month to the specified date.
DAYOFWEEK(e) Returns the day of the week on which the specific date falls.
HOUR(e) Returns the hour field of the specified time expression.
LOCATE(s1,s2[,p]) Returns the position in s2 where the substring s1 starts.
MINUTE(e) Returns the minute field of the specified time expression.
MOD(x1, x2) Returns the remainder from a division.
MONTH(e) Returns the number of months from the beginning of the year to the specified date.
NOW() Returns the current date and time.
SECOND(e) Returns the second field of the specified time expression.
UCASE(s) Returns an equal string, which all lowercase characters convert to uppercase.
WEEK(e) Returns the number of weeks from the beginning of the year to the specified date.
YEAR(e) Returns the year of the specified date.