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
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
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
This article mainly introduces how to use the ALTER command in MySQL, which is the basic knowledge in MySQL beginners. it is very useful for anyone who needs it to refer to the ALTER command in MySQL, if you want to change the table name, table
Detailed description of the use of the ALTER command in MySQL, mysqlalter
MySQL's ALTER command is very useful when you want to change the table name, table fields, or if you want to add or delete columns in an existing table.
Let's start to create
MySQL常用指令,java,php程序员,数据库工程师必备。程序员小冰常用资料整理MySQL common commands (for reference)The most common display commands are:1. Display the list of databases.show databases;2. Display the data table in the library:Use MySQL;Show tables;3, display the
MySQL's alter command is very useful when you want to change the name of the table, the field of the table, or if you want to add or delete columns from an existing table.
Let's start by creating a use case with a table named Testalter_tbl:
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_
MySQL ALTER and mysqlalter
When we need to modify the data table name or field, we need to use the MySQL ALTER command.
Before starting this chapter, let's create a table named testalter_tbl.
root@host# mysql -u root -p password;Enter password:******
MySQL for relational databases (relational database Management System), this so-called "relational" can be understood as the concept of "table", a relational database consists of one or several tables.
We need to use the MySQL alter command when we
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