Inserting Persons with IDs in one query?

Question

I need to add data to a MySQL database like that:

Person: pId, nameId, titleId, age

Name: nameId, name

Title: titleId, title

I don't want to have any names or title more then once in the db so I didn't see a solution with LAST_INSERT_ID()

My approach looks like that:

INSERT IGNORE INTO Name(name) VALUES ("Peter");
INSERT IGNORE INTO Title(title) VALUES ("Astronaut");
INSERT INTO Person(nameId, titleId, age) VALUES ((SELECT nameId FROM Name WHERE name = "Peter"), (SELECT nameId FROM Name WHERE name = "Astronaut"), 33);

But I guess that's a quite dirty approach!? If possible I want to add multiple persons with one query and without having anything more then one times in db. Is this possible in a nice way? Thanks!

Answer 1

You could put title and name as two columns of your table and then:

• set one UNIQUE index on each column if you don"t want to have two titles or two names identical in the DB
• or set an UNIQUE index on (title,name) if you don't want to have two entries having both the same name and the same title.

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If you really want to have separate tables, you could do as you suggested in your post, but wrapping all your insert statements in a TRANSACTION to allow rollback if you detect a duplicate somewhere.

See Design dilemma: If e-mail address already used, send e-mail "e-mail address already registered", but can't because can't add duplicate to table which appear to be exactly the same problem, but having name & email instead of name & titles.

START TRANSACTION;
INSERT INTO title(value) VALUES ("Prof.");
SELECT LAST_INSERT_ID() INTO @title_id; 
    -- Instead of using user-defined variable, 
    -- you should be able to use the last_insert_id 
    -- equivalent from the host language MySQL driver.
INSERT INTO username(value) VALUES ("Sylvain");
SELECT LAST_INSERT_ID() INTO @username_id;
    -- Instead of using user-defined variable, 
    -- you should be able to use the last_insert_id 
    -- equivalent from the host language MySQL driver.

INSERT INTO account(username_id, email_id) VALUES (@username_id,@title_id); 
COMMIT;

See LAST_INSERT_ID()

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A third solution would be to SELECT before doing you insert to see in the entry are already present. But personally I wouldn't push to the check-before-set approach at the very least, this will require an extra query which is mostly superfluous if you use correctly indexes.