MySQL database ALTER command explanation, MySQL ALTER command explanation
MySQL is a Relational Database Management System. This so-called "Relational" can be understood as "tables". A Relational Database consists of one or more tables.
When we need
First, basic usage
1. Add Column
ALTER TABLE Tbl_name add col_name type
For example, add a column of weight to the pet table,
Mysql>alter table Pet Add weight int;
2. Delete Column
ALTER TABLE Tbl_name drop col_
ALTER TABLE allows you to modify the structure of an existing table. For example, you can add or delete columns, create or eliminate indexes, change the type of existing columns, or rename columns or the table itself. You can also change the
The following articles mainly describe the actual operations of modifying the alter TABLE structure in MySQL. If you are interested in the actual operations of modifying the alter TABLE structure in MySQL, you can browse the following articles, the
MySQL is a relational database (RelationalDatabaseManagementSystem ). This article focuses on the alert commands of the mysql Database. This article is very detailed and has reference value. if you are interested, join us and learn that MySQL is a
MySQL study Note 5: modifying the table (altertable) bitsCN.com we will inevitably consider the week before creating the table. Therefore, the alter table statement is required to modify the table later.
Modify table name
Mysql> alter table
When creating a table, we will inevitably consider the disadvantages of weeks. Therefore, we need to use altertable to modify the TABLE statement to modify the table later. Next we will introduce it in detail. For more information, see
When creating
When we create a table, we will inevitably think of it poorly, so we later modify the table modification table to use the ALTER TABLE statement
Modify Table name
Copy Code code as follows:
mysql> ALTER TABLE student rename person;
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