MySQL-Operating data

Overview

The 3 basic Data Manipulation Language (DML) commands in SQL are:

>insert

>update

>delect

1. Populating a table with new data

1) Data Insertion table

Insert  into table_name Values ('value1','value2',[null] );

Numeric or null values are not enclosed in single quotes, others must have single quotes

2) Insert data to the specified column

Insert  into table_name ('column1'column2')  Values('value1','value2');

3) inserting data from another table

By combining the INSERT statement with the SELECT statement, you can insert query results from one table into the other.

Insert  into [(' column1 ', ' Column2 ')] Select [*| (' Column1 ', ' Column2 ')]from[where]

3. Updating existing data

Update table_name set column1='value1',    [column2= ' value2 '  ],  [column3= ' value3 '][where]

4. Deleting data from the table

Delete  from table_name [where]

The Delete command cannot delete data from a column, but instead deletes the entire row of data.

MySQL-Operating data