Top "Constraints" questions

Ruby on Rails: How do I add a not null constraint to an existing column using a migration?

In my Rails (3.2) app, I have a bunch of tables in my database but I forgot to add a few …

ruby-on-rails database migration constraints notnull

Limit SQL Server column to a list of possible values

How do I put a constraint on a column so that it can only contain the following values? What do …

sql-server database constraints

How do you drop a default value or similar constraint in T-SQL?

I know the syntax: ALTER TABLE [TheTable] DROP CONSTRAINT [TheDefaultConstraint] but how to I drop the default constraint when I …

sql tsql constraints default

Template Constraints C++

In C# we can define a generic type that imposes constraints on the types that can be used as the …

c++ templates constraints

Constraint name update in PostgreSQL

Is it possible to change the constraint name in Postgres? I have a PK added with: ALTER TABLE contractor_contractor …

postgresql constraints

How to truncate all user tables?

How can I truncate all user table in oracle? I have problem with tables constraints.

oracle constraints truncate

Postgresql: Conditionally unique constraint

I'd like to add a constraint which enforces uniqueness on a column only in a portion of a table. ALTER …

postgresql constraints unique-constraint

Oracle - drop table constraints without dropping tables

I'm doing some bulk migration of a large Oracle database. The first step of this involves renaming a whole load …

sql oracle constraints rename table-rename

How do I define a generic class that implements an interface and constrains the type parameter?

class Sample<T> : IDisposable // case A { public void Dispose() { throw new NotImplementedException(); } } class SampleB<T> where …

c# generics inheritance constraints

How can a not null constraint be dropped?

Let's say there's a table created as follows: create table testTable ( colA int not null ) How would you drop the …

mysql null constraints