The following case studies for SQL Server demonstrate some of the features of the Oracle Database Gateway. You can verify that the gateway is installed and operating correctly by using the demonstration files included in the distribution media.
The demonstration files are automatically copied to disk when the gateway is installed.
This chapter contains the following sections:
The cases illustrate:
A simple query (Case 1)
A more complex query (Case 2)
Joining SQL Server tables (Case 3)
Write capabilities (Case 4)
A data dictionary query (Case 5)
The pass-through feature (Case 6)
Executing stored procedures (Case 7)
The installation media contains the following:
Demonstration files
One SQL script file that creates the demonstration tables and stored procedures in the SQL Server database
One SQL script file that drops the demonstration tables and stored procedures from the SQL Server database
After a successful gateway installation, use the demonstration files stored in the directory ORACLE_HOME\dg4msql\demo where ORACLE_HOME is the directory under which the gateway is installed. The directory contains the following demonstration files:
The case studies assume these requirements have been met:
The gateway demonstration tables and stored procedures are installed in the SQL Server database
The Oracle database has an account named SCOTT with a password of TIGER
The Oracle database has a database link called GTWLINK (set up as public or private to the user SCOTT) which connects the gateway to a SQL Server database as SCOTT with password TIGER2
For example, you can create the database link as follows:
SQL> CREATE DATABASE LINK GTWLINK CONNECT TO SCOTT 2 IDENTIFIED BY TIGER2 USING 'GTWSID';
Oracle Net Services is configured correctly and running
The case studies are based on the GTW_EMP, GTW_DEPT, and GTW_SALGRADE tables and the stored procedures InsertDept and GetDept. If the demonstration tables and stored procedures have not been created in the SQL Server database, use the bldmsql.sql script to create them. Enter the following:
> isql -USCOTT -PTIGER2 -ibldmsql.sql
The script creates the demonstration tables and stored procedures in the SQL Server database accordingly:
CREATE TABLE GTW_EMP ( EMPNO SMALLINT NOT NULL ENAME VARCHAR(10), JOB VARCHAR(9), MGR SMALLINT, HIREDATE DATETIME, SAL NUMERIC(7,2), COMM NUMERIC(7,2), DEPTNO SMALLINT) go CREATE TABLE GTW_DEPT ( DEPTNO SMALLINT NOT NULL, DNAME VARCHAR(14), LOC VARCHAR(13)) go CREATE TABLE GTW_SALGRADE ( GRADE MONEY, LOSAL NUMERIC(9,4), HISAL NUMERIC(9,4)) go DROP PROCEDURE InsertDept go CREATE PROCEDURE InsertDept (@dno INTEGER, @dname VARCHAR(14), @loc VARCHAR(13)) AS INSERT INTO GTW_DEPT VALUES (@dno, @dname, @loc) go DROP PROCEDURE GetDept go CREATE PROCEDURE GetDept (@dno INTEGER, @dname VARCHAR(14) OUTPUT) AS SELECT @dname=DNAME FROM GTW_DEPT WHERE DEPTNO=@dno go
The following table definitions use information retrieved by the SQL*PLUS DESCRIBE command:
GTW_EMP
Name Null? Type ------------------------------- -------- ---- EMPNO NOT NULL NUMBER(5) ENAME VARCHAR2(10) JOB VARCHAR2(9) MGR NUMBER(5) HIREDATE DATE SAL NUMBER(7,2) COMM NUMBER(7,2) DEPTNO NUMBER(5)
GTW_DEPT
Name Null? Type ------------------------------- -------- ---- DEPTNO NOT NULL NUMBER(5) DNAME VARCHAR2(14) LOC VARCHAR2(13)
GTW_SALGRADE
Name Null? Type ------------------------------- -------- ---- GRADE NUMBER(19,4) LOSAL NUMBER(9,4) HISAL NUMBER(9,4)
The contents of the SQL Server tables are:
GTW_EMP
EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO ----- ----- --- --- -------- --- ---- ------ 7369 SMITH CLERK 7902 17-DEC-80 800 20 7499 ALLEN SALESMAN 7698 20-FEB-81 1600 300 30 7521 WARD SALESMAN 7698 22-FEB-81 1250 500 30 7566 JONES MANAGER 7839 02-APR-81 2975 20 7654 MARTIN SALESMAN 7698 28-SEP-81 1250 1400 30 7698 BLAKE MANAGER 7839 01-MAY-81 2850 30 7782 CLARK MANAGER 7839 09-JUN-81 2450 10 7788 SCOTT ANALYST 7566 09-DEC-82 3000 20 7839 KING PRESIDENT 17-NOV-81 5000 10 7844 TURNER SALESMAN 7698 08-SEP-81 1500 0 30 7876 ADAMS CLERK 7788 12-JAN-83 1100 20 7900 JAMES CLERK 7698 03-DEC-81 950 30 7902 FORD ANALYST 7566 03-DEC-81 3000 20 7934 MILLER CLERK 7782 23-JAN-82 1300 10
GTW_DEPT
DEPTNO DNAME LOC ----- -------------- -------- 10 ACCOUNTING NEW YORK 20 RESEARCH DALLAS 30 SALES CHICAGO 40 OPERATIONS BOSTON
GTW_SALGRADE
GRADE LOSAL HISAL
------ ------ -----
1 700 1200
2 1201 1400
3 1401 2000
4 2001 3000
5 3001 9999
Case 1 demonstrates the following:
A simple query
A simple query retrieving full date information
The first query retrieves all the data from GTW_DEPT and confirms that the gateway is working correctly. The second query retrieves all the data from GTW_EMP including the time portion of the hire date because the default date format was set to DD-MON-YY HH24:MM:SS for the session by an ALTER SESSION command.
Case 2 demonstrates the following:
The functions SUM(expression) and NVL(expr1, expr2) in the SELECT list
The GROUP BY and HAVING clauses
This query retrieves the departments from GTW_EMP whose total monthly expenses are higher than $10,000.
Case 3 demonstrates the following:
Joins between SQL Server tables
Subselects
The query retrieves information from three SQL Server tables and relates the employees to their department name and salary grade, but only for those employees earning more than the average salary.
Case 4 is split into three cases and demonstrates the following:
Case 4a demonstrates bind values and subselect. All employees in department 20 and one employee, WARD, in department 30 are deleted.
Case 4b provides an example of a simple UPDATE statement. In this example, employees are given a $100 a month salary increase.
Case 5 demonstrates data dictionary mapping. It retrieves all the tables and views that exist in the SQL Server database that begin with GTW.
Case 6 demonstrates the gateway pass-through feature which allows an application to send commands or statements to SQL Server.
This case demonstrates:
A pass-through UPDATE statement using bind variables
A pass-through SELECT statement