There are 5 common database query statements in mysql: 1. "SELECT" statement, used to select data from one or more tables; 2. "INSERT INTO" statement, used to insert new data into a table ;3. The "UPDATE" statement is used to modify existing data; 4. The "DELETE" statement is used to delete data in the table; 5. The "CREATE TABLE" statement is used to create a new table.
The operating system of this tutorial: Windows 10 system, mysql5.0.27 version, Dell G3 computer.
MySQL is a very popular relational database management system that supports many different types of query statements to retrieve, insert, update and delete data.
The following are several commonly used MySQL query statements:
1. SELECT: used to select data from one or more tables
Sample code:
SELECT * FROM mytable; SELECT firstname, lastname FROM customers WHERE city='New York';
2. INSERT INTO: used to insert new data into a table
Example code:
INSERT INTO mytable (id, name) VALUES (1, 'John');
3. UPDATE: used to modify existing data
Example Code:
UPDATE mytable SET name='Peter' WHERE id=1;
4, DELETE: used to delete data in the table
Sample code:
DELETE FROM mytable WHERE id=1;
5, CREATE TABLE: used to create a new table.
Sample code:
CREATE TABLE mytable ( id INT(6) UNSIGNED AUTO_INCREMENT PRIMARY KEY, name VARCHAR(30) NOT NULL, email VARCHAR(50), reg_date TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP );
These are just part of the MySQL query statements. Developers can also use other types of queries to meet their specific needs. When using these statements in your application, you must ensure that you connect to the MySQL database correctly and that sensitive data is properly processed and validated.
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