Developing a point-of-sale system that uses a MS Access database. We'd like to use our program to create all the necessary tables and their fields in the database when the user starts up a new ...

SQL Server instances, even if equipped with provisions like automatic backup and recovery, are not sufficiently protected against sudden, disastrous situations like multi-site database failure, ...

Primary keys come from candidate keys. Each candidate key consists of the attribute or attributes used to label a distinct row in a table. Every candidate key should contain the fewest number of ...

I'm adding a table and subclass table to my DB. (Subclass table = table where the primary key joins to the primary key of another table, to give extra row information to some subset of the rows ...

In Microsoft SQL Server, for example, a primary key usually equates to a clustered index. In SQLite, a primary key is usually just a unique index and is distinct from the special rowid column name.

In Microsoft SQL Server, for example, a primary key usually equates to a clustered index. In SQLite, a primary key is usually just a unique index and is distinct from the special rowid column name.

Under far too many circumstances, those responsible for modeling data are ignoring the above perspective on primary keys and are simply defining surrogate keys for everything in their data model. One ...

Duplicate and Ignore on MySQL Inserts. MySQL table primary keys and unique indexes prevent multiple rows with the same index from being added to the table. If you try to insert a duplicate row ...