The cteinsertstrategy
can only be used with dialects that support Common Table Expressions (CTE) that can
take update or delete statements as well. CTE allows you to define temporary named result sets within a SQL statement,
which can be referenced later within that statement.
Here’s an example to illustrate the usage of cteinsertstrategy
with CTE:
-- Suppose we have a table called 'employees' with columns 'id', 'name', 'salary', and 'department_id'
WITH updated_salary AS (
SELECT id, salary * 1.1 AS new_salary
FROM employees
WHERE department_id = 1
)
INSERT INTO employees (id, name, salary, department_id)
SELECT id, name, new_salary, department_id
FROM updated_salary;
In the above example, we first define a CTE called updated_salary
which selects the employees with a
department_id of 1 and calculates their new_salary by multiplying the existing salary by 1.1. This CTE is then used in
the INSERT statement to insert the updated salaries into the ’employees’ table.