UPDATE. Oracle 11g Release 1 SQL Server

Oracle Functions

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CONNECT BY

condition

NOWAIT

START WITH

condition

WHERE CURRENT

OF

UPDATE

The UPDATE statement is fully supported. However, only Oracle functions supported by SQL Server can be used.

See Also:

"Functions Supported by SQL Server" on page B-2 for a

list of supported functions.

Oracle Functions

All functions are evaluated by the SQL Server database after the gateway has converted them to SQL Server SQL equivalents. The exception is the TO_DATE function, which is evaluated by the gateway.

Functions Not Supported by SQL Server

Oracle SQL functions with no equivalent function in SQL Server are not supported in

DELETE

, INSERT, or UPDATE statements, but are evaluated by the Oracle database if the statement is a SELECT statement. That is, the Oracle database performs post-processing of SELECT statements sent to the gateway.

If an unsupported function is used in a DELETE, INSERT, or UPDATE, statement, the following Oracle error occurs:

ORA-02070: database db_link_name does not support function in this context

Functions Supported by SQL Server

The gateway translates the following Oracle database functions in SQL statements to their equivalent SQL Server functions:

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Arithmetic Operators

Comparison Operators

Pattern Matching

Group Functions

String Functions

Other Functions

Arithmetic Operators

*

/

Oracle

+

-

*

/

SQL Server

+

-

B-2 Oracle Database Gateway for Microsoft SQL Server User’s Guide

Oracle Functions

Comparison Operators

Oracle

=

>

<

>=

<=

<>, !=, ^=

IS NOT NULL

IS NULL

Pattern Matching

Oracle

LIKE

NOT LIKE

Group Functions

Oracle

AVG

COUNT

MAX

MIN

SUM

String Functions

Oracle

||, CONCAT

ASCII

CHR

INSTR

(with two arguments)

LENGTH

LOWER

LTRIM

RTRIM

SUBSTR

(second argument cannot be a negative number)

UPPER

<

>=

<=

<>

SQL Server

=

>

IS NOT NULL

IS NULL

SQL Server

LIKE

NOT LIKE

SQL Server

AVG

COUNT

MAX

MIN

SUM

SQL Server

+

(expression1 + expression2)

ASCII

CHAR

CHARINDEX

DATALENGTH

LOWER

LTRIM

RTRIM

SUBSTRING

UPPER

Supported SQL Syntax and Functions B-3