How do you make sure there are no duplicates in Access?

How do I show only unique values in an Access query?

Answer: Open your query in design view. Right-click somewhere in the Query window beside a table (but not on a table) and select Properties from the popup menu. Set the "Unique Values" property to Yes.

How do you prevent duplicate data entry?

How To Prevent Duplicate Data Entries1Select the full column of data which we're going to limit to unique values.2Go to the Data tab.3Press the Data Validation button.4Select Data Validation from the drop down menu.5Select the Settings tab.6In the Allow drop down select Custom.7In the Formula area input this formula.

How do you prevent duplicates in a query?

Using COUNT(*) = 0. To avoid duplicates, the COUNT or records returned by the subquery above should be zero.

Why does my Access query show duplicates?

Duplicate data often creeps in when multiple users add data to the Access database at the same time or if the database wasn't designed to check for duplicates. Duplicate data can be either multiple tables containing the same data or two records containing just some fields (columns) with similar data.