Postgres date overlapping constraint

Question

I have a table like this:

date_start    date_end     account_id    product_id
2001-01-01    2001-01-31   1             1
2001-02-01    2001-02-20   1                 


        

Answer 1

How to create unique constraint to a group of columns :

 CREATE TABLE table (
    date_start date,
    date_end  date,
    account_id integer,
    UNIQUE (account_id , date_start ,date_end) );

in your case you will need to ALTER TABLE if the table already exists, check the documentation it would be helpful for you :
- DDL Constraints
- ALTER Table