Quantcast
Browsing latest articles
Browse All 25 View Live

Modify table constraint in PostgreSQL

Say I have a constraint ALTER TABLE distributors ADD CONSTRAINT zipchk CHECK (char_length(zipcode) = 5); that needs to be modified so that zipcode length is 6. Do I have the drop the constraint zipchk...

View Article


is_not_trusted = 1 after Error-Free WITH CHECK CHECK CONSTRAINT

I’d like SQL Server 2005 SP4 to trust a certain foreign key constraint. Executing an ALTER TABLE statement that enables + checks the constraint returns Command(s) completed successfully yet...

View Article


Cascade deletes from multiple tables

I have a fairly standard restaurant model with a restaurant table in a PostgreSQL DB. All restaurants have ratings (which consist of average, vote_count and vote_sum) but in order to avoid repeating...

View Article

How to calculate integral of density under constraint?

Given a bivariate standard-normally distributed random variable $Y=[Y_1,Y_2]^T$ with density $phi(Y_i,Y_2)$, the probability of $Y_1>0$ is simply $$P(Y_1 > 0)=1- int_{-infty}^{infty}...

View Article

How to implement a 'default' flag that can only be set on a single row

For example, with a table similar to this: create table foo(bar int identity, chk char(1) check (chk in('Y', 'N'))); It doesn’t matter if the flag is implemented as a char(1), a bit or whatever. I just...

View Article


Read only postgres table, except by trigger

Suppose the following situation: I have a product_stock table and a stock_transaction_log table. Currently whenever there is an increase/decrease in a product’s stock, I update the product_stock table...

View Article

Constraint to prevent overlapping Time periods

I have a pretty simple table that stores a StartTime and an EndTime, both with the data type of Time(0). I need to enforce a constraint that prevents any overlapping. ‘Touching’ time periods are OK,...

View Article

Constraint Information – PostgreSQL 9.2

I was trying to delete some data from the table dm.billables: 1 – Select the id – PASS SELECT * INTO junk.clientid_10306 FROM dm.billables WHERE account_id = 10306; 2 – Delete the data from the table...

View Article


Don't know why MySQL is not creating table with primary key constraint [closed]

I can’t understand why MySQL showing this error: #1064 – You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near...

View Article


Check constraint

check (phone like'[0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9]') This is to check the phone number whether it has exactly 10 digits. But I have no idea about placing number as '[0-9]'. It seems...

View Article
Browsing latest articles
Browse All 25 View Live