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CRUD operation of MySql: how to quickly complete addition, deletion, modification and query
CRUD operation of MySql: how to quickly complete addition, deletion, modification and query
MySql is a relational database management system that is very commonly used in web applications. In the entire web application development process, CRUD (Create, Delete, Modify and Check) operations are essential. This article will introduce how to quickly complete these operations in MySql.
- Increase (Create)
In MySql, we use the INSERT INTO statement to insert new rows. For example, we have a table called "users" with three columns: "id", "name" and "email". Now to add a new row of data to the table, you can use the following code:
INSERT INTO users (name, email) VALUES ('Tom', 'tom@example.com');- Delete (Delete)
In MySql, use the DELETE statement to delete rows in the table. For example, we want to delete the row named "Tom" in the "users" table, the code is as follows:
DELETE FROM users WHERE name='Tom';
Please note that this will delete all records named "Tom" from the database, Therefore it should be used with caution.
- Modify (Update)
Use the UPDATE statement to modify rows in the table. For example, if we want to change the email address named "Tom" to "tommy@example.com", we can use the following code:
UPDATE users SET email='tommy@example.com' WHERE name='Tom';
- Query (Select)
In MySql , the SELECT statement is used to query data in the data table. For example, if we want to query all rows with the name "Tom", we can use the following code:
SELECT * FROM users WHERE name='Tom';
This will return all records with the name "Tom".
MySql also allows the use of statistical functions to help us retrieve data. For example, if we want to count the total number of records in the "users" table, we can use the following code:
SELECT COUNT(*) FROM users;
If we want to count the total number of records for all user names starting with "T", we can use the following code:
SELECT COUNT(*) FROM users WHERE name LIKE 'T%';
This will return the total number of records starting with "T".
Conclusion
In MySql, CRUD operations make adding, deleting, updating and querying data simple and efficient. This article explains how to use INSERT INTO, DELETE, UPDATE, and SELECT statements to accomplish these operations to make your application development more efficient and faster.
The above is the detailed content of CRUD operation of MySql: how to quickly complete addition, deletion, modification and query. For more information, please follow other related articles on the PHP Chinese website!
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