Detailed Explanation of replace into Example of mysql

Detailed Explanation of replace into Example of mysql

replace into is similar in functionality to insert except that replace into first attempts to insert data into a table.

1. If you find that there is already this row of data in the table (judged according to the primary key or the only 1 index), delete this row of data first, and then insert new data.

2. Otherwise, insert new data directly.

Note that the table inserting data must have a primary key or a only 1 index! Otherwise, replace into inserts data directly, resulting in duplicate data in the table.

There are three ways to write replace into in MySQL:

The code is as follows:

 replace into table(col, ...) values(...)
 replace into table(col, ...) select ...
 replace into table set col=value, ...

Extension: mysql gets the last primary key of the corresponding insertion (1 user gets the primary key order number of the order table)

SELECT LAST_INSERT_ID() from dual 

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