Hi everyone, I'm working on a project involving C# and a SQL Server 2008 database. In one of the tables, I have a field (nvarchar(15)) which will contain an IP address. I'd like to add a check constraint which will validate that the input value is actually an IP address. I wanted to use a regex to do that, but it seems that this featu...
Does MySQL support check constraint? I am able to execute the following script in MySQL without error. ALTER TABLE EMP_DB_DESIGN_EXCEL ADD ( CONSTRAINT CHK_EMP_IS_ACTIVE CHECK (IS_ACTIVE IN ('Y','N'))); But it is not reflected if I query: SELECT * FROM information_schema.TABLE_CONSTRAINTS T where t.table_name='EMP_DB_DESIGN_EX...
I have the following tables in a SQL Server 2008 db: tblItem, which has an ItemID field; tblGoodItem, which also has an ItemID field, and has a foreign key pointing to tblItem; tblBadItem, which also has an ItemID field, and also has a foreign key pointing to tblItem. An item cannot be both a good item and a bad item; it must either ...
I need to have a table in T-SQL which will have the following structure KEY Various_Columns Flag 1 row 1 F 2 row_2 F 3 row_3 T 4 row_4 F Either no rows, or at most one row can have the Flag column with the value T. My developer claims...
My question is sort of similar to this one I want to check if a DELETE query will fail because of a constraint violation. I'd like to do this on database level because I think letting it fail and catching the error is ugly. Another option is "manually" checking for it using SELECT queries to see if there are constraints, but this is ra...