How do I insert record ID of one table, to another table as a foreign key

Question

0.00/5 (No votes)

See more:

I have table1 and table2.
Primary key of table1 is auto updating recordID.
Foreign key of table2 is recordID of the table1.
What I'm currently doing is,
First insert to table1,

SQL

INSERT INTO table1(col1, col2, col3) VALUES (val1, val2 val3)

Then select the auto updated record id of the inserted record,

SQL

SELECT table1RecordID FROM table1 ORDER BY table1RecordID DESC LIMIT 1

And insert that record id to the table2 as the foreign key.

SQL

INSERT INTO table2(foreignKeyCol, col1, col2) VALUES (table1ReacordID, val1, val2)

Are there any other preferable ways of doing this?

Posted 3-Sep-15 21:12pm

Sherantha

Add a Solution

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

OriginalGriff · Accepted Answer · 2015-09-03T21:41:00

Don't do it like that! MySQL and MSSQL are multiuser systems, so there is no guarantee that your select will retrieve the ID of the record you just entered - there is nothing that stops a different user entering a record after you do, and before your select.
Instead, either use @@IDENTITY to retrieve the last automatically generated ID on teh current connection (you can use LAST_INSERT_ID()[^] as well, but @@IDENTITY works for MSSQL and MYSQL as well) or better, use GUID ID's and set them from your other code - that way you don't need to fetch anything once inserted.

SQL

INSERT INTO table1(col1, col2, col3) VALUES (val1, val2 val3)
INSERT INTO table2(foreignKeyCol, col1, col2) VALUES (@@IDENTITY, val1, val2)