I know that SQL constraints can force data to meet validity criteria. However, what about criteria such as "Student's grade can only be updated when the 'finalised' flag is false"? Do such update c...

I have a table, ProductSupportArticles: ProductSupportArticleID int NOT NULL <primary key> ParentArticleID int NULL ProductID int NOT NULL Title varchar(100) NOT NULL Content varchar(MAX) NO...

Im getting this error: ORA-00904: "M": invalid identifier --> if I put ('M','F') //single quotation i got this error message: PLS-00103: Encountered the symbol "M" when expecting one of the followi...

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 m...

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 ...

I've had this come up a couple times in my career, and none of my local peers seems to be able to answer it. Say I have a table that has a "Description" field which is a candidate key, except that ...

Please imagine this small database... Diagram removed dead ImageShack link - volunteer database diagram Tables Volunteer Event Shift EventVolunteer ========= ===== ===== ============== Id Id Id...

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 fa...

I am trying to create a Basic pay (BP) table with CREATE TABLE bp ( bpid VARCHAR(5), FOREIGN KEY (bpid) REFERENCES designation(desigid), upperlimit DECIMAL(10,2) NOT NULL, lowerlimit DECIMA...