check-constraints

This is probably a simple answer but I can't find it. I have a table with a column of integers and I want to ensure that when a row is inserted that the value in this column is greater than zero. I could do this on the code side but thought it would be best to enforce it on the table. Thanks! I was in error with my last comment all is good now. You can use a check constraint on the column. IIRC the syntax for this looks like: create table foo ( [...] ,Foobar int not null check (Foobar > 0) [...] ) As the poster below says (thanks Constantin), you should create the check constraint outside the

I'm using SQLite, which doesn't support adding a constraint to an existing table. So I can't do something like this (just as an example): ALTER TABLE [Customer] ADD CONSTRAINT specify_either_phone_or_email CHECK (([Phone] IS NOT NULL) OR ([Email] IS NOT NULL)); Are there any workarounds for this scenario? I know: I can add a constraint for a new table, but it isn't new (and it's generated by my ORM, EF Core) I can do a "table rebuild" (rename table, create new one, copy old data, drop temp table) but that seems really complex Ideas Can I somehow make a copy of the table into a new table, with

I have a table of users eg: create table "user" ( id serial primary key, name text not null, superuser boolean not null default false ); and a table with jobs: create table job ( id serial primary key, description text ); the jobs can be assigned to users, but only for superusers. other users cannot have jobs assigned. So I have a table whereby I see which job was assigned to which user: create table user_has_job ( user_id integer references "user"(id), job_id integer references job(id), constraint user_has_job_pk PRIMARY KEY (user_id, job_id) ); But I want to create a check constraint that

I have a VARCHAR(30) column in a Microsoft SQL Server database. I'd like to add a CHECK constraint that does not allow a value in the column to be less than 3 characters. What is the expression I must use? use: ALTER TABLE [dbo].[YOUR_TABLE] ADD CONSTRAINT [MinLengthConstraint] CHECK (DATALENGTH([your_column]) > 2) Reference: DATALENGTH vs LEN SQL SERVER – 2005 Constraint on VARCHAR(MAX) Field To Limit It Certain Length 来源： https://stackoverflow.com/questions/4426005/how-can-i-create-a-check-constraint-on-a-varchar-column-in-sql-server-specifying

2nd Edit : The source code for the involved function is as follows: ALTER FUNCTION [Fileserver].[fn_CheckSingleFileSource] ( @fileId INT ) RETURNS INT AS BEGIN -- Declare the return variable here DECLARE @sourceCount INT ; -- Add the T-SQL statements to compute the return value here SELECT @sourceCount = COUNT(*) FROM Fileserver.FileUri WHERE FileId = @fileId AND FileUriTypeId = Fileserver.fn_Const_SourceFileUriTypeId() ; -- Return the result of the function RETURN @sourceCount ; END Edit : The example table is a simplification. I need this to work as a Scaler Function / CHECK CONSTRAINT

It seems that some scripts generated by Enterprise Manager* (or not, it doesn't matter) created check constraints WITH NOCHECK . Now when anyone modifies the table, SQL Server is stumbling across failed check constraints , and throwing errors. Can i make SQL go through all its check constraints, and check them? Running: sp_msforeachtable 'ALTER TABLE ? CHECK CONSTRAINT all' only enables previously disabled check constraints, it doesn't actually check them. Footnotes * SQL Server 2000 Nathan DBCC CHECKCONSTRAINTS WITH ALL_CONSTRAINTS won't actually make your constraints trusted. It will report