How to perform basic SQL queries?
To execute basic SQL queries, one must first connect to a database management system such as MySQL, SQL Server, or Oracle, and then open an SQL query editor or command line terminal. Next, input the SQL query statement and execute it. Here is a simple example:
Assuming there is a table named “students” with fields id, name, and age, to retrieve all the information about students, you can use the following SQL query statement:
SELECT * FROM 学生;
After executing the query statement, all the information of students in the student table will be returned. If you want to query data based on specific conditions, you can use the WHERE clause, for example, to query students older than 18 years old:
SELECT * FROM 学生 WHERE 年龄 > 18;
In addition to the SELECT statement, you can also use other SQL query statements such as INSERT (to insert new data), UPDATE (to update data), and DELETE (to delete data). Specific syntax and usage can be found in the respective database management system’s documentation or tutorials.