SELECT query with a variable for the table name so that condition determines which table the result set is based on. : Dynamic SQL « Transact SQL « SQL Server / T-SQL Tutorial

1. SQL Server / T-SQL Tutorial
2. Transact SQL
3. Dynamic SQL

4>
5> CREATE TABLE sales(
6>    stor_id        char(4)           NOT NULL,
7>    ord_num        varchar(20)       NOT NULL,
8>    ord_date       datetime          NOT NULL,
9>    qty            smallint          NOT NULL,
10>    payterms       varchar(12)       NOT NULL,
11>    title_id       varchar(80)
12> )
13> GO
1> insert sales values('1', 'QA7442.3', '09/13/94', 75, 'ON Billing','1')
2> insert sales values('2', 'D4482',    '09/14/94', 10, 'Net 60',    '1')
3> insert sales values('3', 'N914008',  '09/14/94', 20, 'Net 30',    '2')
4> insert sales values('4', 'N914014',  '09/14/94', 25, 'Net 30',    '3')
5> insert sales values('5', '423LL922', '09/14/94', 15, 'ON Billing','3')
6> insert sales values('6', '423LL930', '09/14/94', 10, 'ON Billing','2')
7> GO

(1 rows affected)

(1 rows affected)

(1 rows affected)

(1 rows affected)

(1 rows affected)

(1 rows affected)
1>
2>     DECLARE @chvTable VARCHAR(30),
3>             @chvSQL VARCHAR(255)
4>     IF getdate() > '7/1/1997'
5>     SELECT @chvTable = 'sales'
6>     ELSE
7>     SELECT @chvTable = 'authors'
8>     SELECT @chvSQL = 'SELECT * FROM ' + @chvTable
9>     EXEC (@chvSQL)
10>     GO
stor_id ord_num              ord_date                qty    payterms     title_id
------- -------------------- ----------------------- ------ ------------ --------------------------------------------------------------------------------
1       QA7442.3             1994-09-13 00:00:00.000     75 ON Billing   1
2       D4482                1994-09-14 00:00:00.000     10 Net 60       1
3       N914008              1994-09-14 00:00:00.000     20 Net 30       2
4       N914014              1994-09-14 00:00:00.000     25 Net 30       3
5       423LL922             1994-09-14 00:00:00.000     15 ON Billing   3
6       423LL930             1994-09-14 00:00:00.000     10 ON Billing   2

(6 rows affected)
1>
2> drop table sales;
3> GO