Combining insert and select to implement the method of "inserting the maximum value of a field in the database + 1"

This article is mysql database

Question 1 Import the data from Table 1 into Table 2:

Import the data from Table 1 into Table 2:

Insert the data in Table 2 into Table 1. The columns in Table 1 correspond to the columns selected in Table 2.

INSERT INTO table1 (column1, column2, column3, column4)
select column1, column2, column3, column4 from table 2

When inserting data into the table in question 2, a field takes the maximum value of the field in the database and adds 1.

When inserting data into a table, a field takes the maximum value of the field in the database and adds 1. Many people say that this problem can be solved by using stored procedures or something. In fact, the combination of insert and select can solve this problem very well.

Example: When inserting a new record into table 1, the age value is the maximum value in the database and added 1, and is stored in the database as the age of the new data. (Of course, the select statement for age can also add a where condition.)

INSERT INTO table1(
      column1, 
      column2, 
      column3, 
      column4,
      age
    )SELECT
      column1, 
      column2, 
      column3, 
      column4,
      (select IFNULL((select max(age) from table name,0)+1);

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