Shulou(Shulou.com)05/31 Report--

In this issue, the editor will bring you about how to delete duplicate records in mysql. The article is rich in content and analyzes and narrates it from a professional point of view. I hope you can get something after reading this article.

1. Confirm the amount of data in the base table and transition table.

Mysql > select count (*) from test

+-+

| | count (*) |

+-+

| | 1572864 |

+-+

1 row in set (2.48 sec)

Mysql > select count (*) from tmp

+-+

| | count (*) |

+-+

| | 0 |

+-+

1 row in set (0.02 sec)

2. Filter duplicate records and insert base table data into transition table

Mysql > insert into tmp select distinct * from test

Query OK, 3 rows affected (3.27 sec)

Records: 3 Duplicates: 0 Warnings: 0

3. Delete the base table data and insert the transition table data back.

Mysql > truncate table test

Query OK, 1572864 rows affected (29.44 sec)

Mysql > insert into test select * from tmp

Query OK, 3 rows affected (0.16 sec)

Records: 3 Duplicates: 0 Warnings: 0

4. Check the basic table data

Mysql > select * from test

+-+ +

| | C1 | c2 |

+-+ +

| | 1 | 1 |

| | 1 | 2 |

| | 2 | 2 |

+-+ +

3 rows in set (0.00 sec)

This is how to delete duplicate records in the mysql shared by the editor. If you happen to have similar doubts, you might as well refer to the above analysis to understand. If you want to know more about it, you are welcome to follow the industry information channel.

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