How to query the database and exclude duplicate records
This article mainly introduces "how to query and eliminate duplicate records in the database". In daily operation, I believe many people have doubts about how to query and eliminate duplicate records in the database. Xiao Bian consulted all kinds of data and sorted out simple and easy operation methods. I hope to help you answer the doubts about "how to query and eliminate duplicate records in the database"! Next, please follow the small series to learn together!
Today, due to work needs, need to find a field in the database under different record values, very simple problem is too complex I think, very depressed, the reason is that a command of SQL forgotten, now the problem has been solved, hurry to do a memo.
In fact, you only need to use the DISTINCT command in SQL, which is very simple. The syntax is as follows:
The copy code is as follows:
SELECT DISTINCT COLUMN NAME FROM TABLE NAME
Examples:
Suppose there is a database table: htmer:
The copy code is as follows:
field001
record 1
record 2
record 1
record 3
Now there are four records in this table, but one record is duplicate. If I want to remove the duplicate record, the SQL statement that lists only the non-duplicate records is:
The copy code is as follows:
SELECT DISTINCT field001 FROM htmer
The results were as follows:
The copy code is as follows:
field001
record 1
record 2
record 3
At this point, the study of "how to query and eliminate duplicate records in the database" is over, hoping to solve everyone's doubts. Theory and practice can better match to help you learn, go and try it! If you want to continue learning more relevant knowledge, please continue to pay attention to the website, Xiaobian will continue to strive to bring more practical articles for everyone!
