MySQL inserts query results into other tables

Learning goals

• Be able to write and insert query results into other tables SQL sentence

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1. reflection

There is only one goods surface , We want to add a product classification information , such as ： Mobile device classification information , Only pass goods The table cannot complete the addition of commodity classification , So how to add commodity classification information ?

answer :

1. Create a commodity classification table , hold goods The commodity classification information in the table is added to the table .
2. take goods The classification name in the table is changed to the corresponding classification in the commodity classification table id

2. Create commodity classification table

--  Create commodity classification table 
create table good_cates(
    id int not null primary key auto_increment, 
    name varchar(50) not null
);

3. hold goods The commodity classification in the table is added to the commodity classification table

--  Inquire about goods Classification information of commodities in the table 
select cate_name from goods group by cate_name;

--  Insert the query results into good_cates In the table 
insert into good_cates(name) select cate_name from goods group by cate_name;

--  Add mobile device classification information 
insert into good_cates(name) values(' Mobile devices ');

explain :

• insert into .. select .. Express : Insert the query results into the specified table , That is, table replication .

4. Summary

• To complete table replication, you can use : insert into .. select .. SQL sentence

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