how to create custom sequence ids with auto increment in mysql

Question

0.00/5 (No votes)

See more:

I have a 'Project' table with columns project_id and project_name and another table 'Task' with coloumns Task_id and task_name.

i want task_id format of project_id + Auto Increment

for example:

project table

project_id project_name
------------------------
1 abc
2 xyz
3 tre

Task Table

Task_id task_name project_id
------------------------------
11 ererer 1
12 asdklasl 1
21 akldjalkdj 2
22 Zdasdad 2
23 ZDmzxm 2
31 dzdldxz 3

for every new project auto increment has to start with 1.

Posted 16-Jul-15 23:14pm

Member 11042471

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)

Wendelius · Answer 1 · 2015-07-16T23:24:00

In my opinion this would be a bad idea. This logic wuold introduce unnecessary complexity to the databsae design and to the programming, how the data base is used. What would be the benefit of this?

For example consider what happens if you have projects 1 and 11 and they have tasks 11 and 1 correspodingly. Both these tasks would have a key value of 111. How to handle this situation...

I would suggest using pure surrogate keys. You can always join the tables when querying and fetch all the relevant data from each table.