I have a multi-column table. The unique identifier is the ID, but my question is as follows:
I have a version column , in it I want to be inserted only one value without repetition. How can I implement this?
I have a multi-column table. The unique identifier is the ID, but my question is as follows:
I have a version column , in it I want to be inserted only one value without repetition. How can I implement this?
You should make your column have a constraint
of type unique
.
In an editor such as SQL Server Management Studio , you should go to table indexes and create a unique index for the column.
I already saw code, you do something like this:
CREATE UNIQUE INDEX NomeDoIndice ON dbo.[Tabela com várias colunas]([Versão]);
Note that the code above assumes that the table actually calls Tabela com várias colunas
and that the column name actually is Versão
. You can use the actual names of your table and column, and the index name can be any arbitrary name.
If you create a single index, every time you try to insert a record into the table with a value in the version column that already exists, SQL will raise an error. The error message will explain that the table does not allow repetition in that column.