SQL statement Delete data table repeating field method, SQL statement _php Tutorial

SQL statement to delete a data table repeating field method, SQL statement

Everyone may encounter field duplication, many people on the web looking for methods, but also give some methods, but some methods are misleading, Optimus write the following methods to facilitate the use of everyone

1. Filter the duplicate fields through group by and create a temp table tmp

CREATE TABLE tmp as SELECT MAX (ID) as col1 from WWW Group by DFDFD;

2. To filter out column col1 that are not on the temporary table from a Deduplication object by using the not in condition to perform a delete operation of not in

3. Delete temporary tables

DROP table tmp;

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