Running A FOREACH after a CTE in a PostgreSQL procedure? - postgresql

Question

I have a PLPGSQL procedure that:
A) Inserts an employee into an Employee table.
B) Also insert the generated serial eid into another Manager table.
C) Finally, the procedure also dictates an array of course_areas that I would like to insert in a specialize table.
Procedure where C and D array are the course_areas
CALL add_employee('Athena', '22222222', 'athena#outlook.com', '2012-12-12', '111', 'instructor', 300.0, NULL,
'{C,D}'::text[]);
Employees
CREATE TABLE Employees (
eid SERIAL PRIMARY KEY,
name TEXT NOT NULL,
phone TEXT NOT NULL,
email TEXT NOT NULL,
join_date DATE NOT NULL,
address TEXT NOT NULL,
depart_date DATE
);
Managers
CREATE TABLE Managers (
eid INT PRIMARY KEY,
monthly_salary DECIMAL(10,2) NOT NULL,
FOREIGN KEY (eid) REFERENCES Employees(eid)
ON DELETE CASCADE
);
Specializes
CREATE TABLE Specializes (
eid INT NOT NULL,
name TEXT NOT NULL,
PRIMARY KEY (eid, name),
FOREIGN KEY (eid) REFERENCES Employees(eid)
on DELETE CASCADE,
FOREIGN KEY (name) REFERENCES Course_areas(name)
on DELETE CASCADE
);
procedure.sql
CREATE OR REPLACE PROCEDURE add_employee (name TEXT, phone TEXT, email TEXT, joinDate DATE, address TEXT, category TEXT, monthlySalary DECIMAL(10,2) default NULL, hourlySalary DECIMAL(10,2) default NULL, courseAreas TEXT[] default NULL)
...
WITH FIRST AS (
INSERT INTO Employees(
name, phone, email, join_date, address
)
VALUES
(
name, phone, email, joinDate, address
) RETURNING eid
),
SECOND AS (
INSERT INTO Full_time_instructors(eid, monthly_salary)
SELECT
eid,
monthlySalary
FROM
ROWS RETURNING eid
)
FOREACH area IN ARRAY courseAreas
LOOP
RAISE NOTICE '%', area; -- should print "C" and "D"
END LOOP;
Error
ERROR: syntax error at or near "FOREACH"
LINE 27: FOREACH area IN ARRAY courseAreas
I can get A) and B) to work.
How can I use FOREACH to iterate through my courseAreas that I pass to the procedure such that I can insert each course area and the eid into a Specialize table?

Answer 1

The FOREACH is a PLPGSQL control structure whereas the CTE is a SQL feature. You can't mix these. Instead of using CTE you can simply perform the first statement, using the RETURNING clause to retrieve the eid to a local variable. You can then use this variable with the subsequent statement and inside your FOREACH loop.
This question gives an overview of getting the new serial value using returning: Get default serial value after INSERT inside PL/pgSQL.