Required fields [duplicate]

1. How do you prevent duplicate data entry for two fields?
2. Is it OK to have duplicate records in a data set?
3. How do I prevent duplicates in Excel data entry?
4. How to avoid duplication of data in SQL?
5. What is duplicate field?

How do you prevent duplicate data entry for two fields?

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).

Is it OK to have duplicate records in a data set?

Generally, duplicate rows are not always allowed in a database or a data table. The regular practice of many companies is to clean their data from such occurrences. However, they are sometimes encountered, especially in new, raw, or uncontrolled data.

How do I prevent duplicates in Excel data entry?

Or simply use the combination of Ctrl + Shift + End. It is important to select the 1st data cell first. Go to Excel "Data" tab and click on the Data Validation icon to open the dialog box. On the Settings tab, choose "Custom" from the Allow drop down list and enter =COUNTIF($D:$D,D2)=1 into the Formula box.

How to avoid duplication of data 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.

What is duplicate field?

This type of transformation is used to create a duplicate field with the same values, essentially creating a “copy” of the field.