Is there an option I can select in SQL management studio, when an int is entered into a it must be unique from all the other columns in that table.
Id Name Code 1 John 3545 2 Mark 454 3 Jim 989
If the user tried to create an account: 4 Mick 3545 - this would fail?
You could add UNIQUE constraints on the columns which you want unique
ALTER TABLE TableName
ADD CONSTRAINT ConstraintName UNIQUE (ColumnName);
GO
What you're asking for sounds like an Identity column. If you make your primary key an identity, you don't need to worry about inserting it - it is auto-incremented with inserts and guaranteed to be unique.
CREATE TABLE Users
(
ID int NOT NULL AUTO_INCREMENT,
//...
PRIMARY KEY (ID)
)
Here is more documentation on the syntax
Make Code primary key in your database.
Yes, you can add unique constraint as part of column definition. Note that if column is primary key, it is unique by definition. See MSDN Create Table page, section on column constraints.
