如何验证特定表字段的内容是否明确？

Question

I am not very into database and I have the following problem: I have a table with many many records and I have to verify if in this table some records have the same value for a specific field (so I have to check if a specific field is not univocal)

So for example I have a table named MaliciousCodeAlertDocument and I want verify if the Title field is an univocal field or not.

What can I do to it? I am thinking that maybe I can use count and group by but I have many doubt about how do it in practice.

Can you help me?

Tnx

Answer 1

Assuming you are using SQL Server and not mysql, you can do it with count and group by:

SELECT Title, COUNT(1) AS TitleCount
FROM MaliciousCodeAlertDocument
GROUP BY Title
HAVING COUNT(1) > 1

This will only return records where the Title field is repeated, so if it returns no records, the field is "univocal".