MySQL is a widely used relational database management system designed to be extremely powerful and easy to use. In the process of using MySQL, we will inevitably encounter situations where we need to delete data in the database table. This article will delve into how to delete table data in MySQL.
There are many ways to delete data in a MySQL table. We will first explore four of them:
Use the DELETE statement to delete data
DELETE FROM table_name;
This is one of the most commonly used methods to delete data in a table. The above statement will delete all data in the table, but the table structure will still be preserved.
Use the TRUNCATE statement to delete data
TRUNCATE table_name;
This statement will delete all data in the table and replace the table with The structure is preserved, but it is much more efficient than using DELETE. This is because the TRUNCATE statement simply truncates the table's data files stored on the hard disk and releases the corresponding storage space, while when executing the DELETE statement, MySQL must scan the table row by row and perform delete operations on each row, which may Will cause time delay.
Use the DROP statement to delete the table
DROP TABLE table_name;
This statement will delete the entire table and its associated indexes , triggers and constraints, etc., so they need to be used with caution.
In MySQL, you can use tool software such as phpMyAdmin and MySQL Workbench to delete tables. They provide basic table management functions, including deleting/copying/editing tables, etc.
Now let us take a look at how to delete MySQL table data through command line operations.
First, open the CMD terminal and enter the server side of MySQL. Then, enter the following command in the terminal to connect to your MySQL database:
mysql -u username -p
Then enter your password, and then enter the following command to enter the MySQL environment:
use DATABASE_NAME
Next, we can use the DELETE statement to delete all data in the table, as shown below:
DELETE FROM table_name;
This command will Delete all data in the table named "table_name". If you want to delete specified rows or specific data, you can use the WHERE clause after the DELETE statement, as shown below:
DELETE FROM table_name WHERE column_name='column_value';
The above command will only Delete data rows that meet the criteria.
Next, we can use the TRUNCATE statement to delete all data in the table, as shown below:
TRUNCATE table_name;
This command will delete the table named "table_name" All data, but retain the table structure.
Finally, we can use the DROP statement to delete the entire table, as shown below:
DROP TABLE table_name;
This command will permanently delete the table named "table_name ” tables and their associated indexes, triggers, constraints, etc., so they need to be used with caution.
To sum up, there are four ways to delete table data in MySQL: deleting data, clearing data, deleting tables, and using tool software. Different methods have different efficiencies and applicable scopes, and they need to be chosen flexibly according to specific circumstances.
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