Add a new field (column) to an existing table in the MySQL database)

-- Note: MySQL has never been used recently because of the need for projects. Although it is used by small and medium-sized enterprises and network companies, it is mainly used across platforms and has a low purchase cost, upgraded to open-source. Therefore, it occupies most of the market share.

Alter table 'database name'. 'table name' add column 'procid' varchar (6) default ''after 'ppidchanged ';

-- In MySQL, if the table name, database name, and column name are used, you must use the accent symbol on the ESC keyboard to add, modify, and update Tables, corresponding column name or update and modify.

 

Here we will simply record what we need to use in our project.