simple correlated query

Database Vuser Scripts · Correlating Database Statements

Creating Vuser Scripts

Chapter 10, page 177

The script below illustrates a simple correlated query. The user performed a query

to retrieve John's ID of 777. A second query on a different table, retrieved the salary

of the employee with the above ID. The user waited for the results of the first query,

before performing the second query.

You can perform an identical operation by nesting the queries. However, the

database statements become complex and difficult to understand.

lrd_stmt(Csr1, "select id from employees where name='John'", ...);
lrd_bind_col(Csr1,1,&ID_D1,...);
lrd_exec(Csr1, ...);
lrd_fetch(Csr1, 1, ...);

lrd_stmt(Csr1, "select salary from payment where id= '777'",...);
lrd_exec(Csr1, ...);

lr_think_time(17);
lrd_stmt(Csr1, "select salary from sal_j1 where id = (select id from "
"emp_j1 where name='John')\n", -1, 1, 1, 0);
lrd_bind_col(Csr1, 1, &SALARY_D11, 0, 0);
lrd_exec(Csr1, 0, 0, 0, 0, 1);
lrd_fetch(Csr1, -1, 1, 0, PrintRow7, 0);