Table with too many columns [duplicate]

1. How do you avoid duplicates in a table?
2. Why am I getting duplicate columns in SQL?
3. How do you prevent duplicates in a column in SQL?

How do you avoid duplicates in a table?

In the Navigation Pane, right-click the table that contains the field, and then click Design View. Select the field that you want to make sure has unique values. In the Field Properties pane at the bottom of the table design view, on the General tab, set the Indexed property to Yes (No duplicates).

Why am I getting duplicate columns in SQL?

This could be because of human error, an application bug, or uncleaned data that's been extracted and merged from external sources, among other things.

How do you prevent duplicates in a column in SQL?

If you want the query to return only unique rows, use the keyword DISTINCT after SELECT . DISTINCT can be used to fetch unique rows from one or more columns. You need to list the columns after the DISTINCT keyword.