SQL The statement used for data retrieval is SELECT. The syntax includes SELECT (specify columns), FROM (specify tables), and WHERE (specify conditions). Examples include retrieving all student names and ages, retrieving students older than 18, and retrieving all information for a specific student.
Data retrieval statement in SQL
The statement used to retrieve data in SQL is SELECT.
Syntax:
SELECT <要检索的列> FROM <表名> WHERE <检索条件>
Component:
- SELECT:Specify what to retrieve List. You can use an asterisk (*) to indicate that all columns are selected.
- FROM: Specify which table to retrieve data from.
- WHERE: Specify the search conditions to filter out rows that meet the conditions.
Example:
Retrieve the names and ages of all students in the student table:
SELECT name, age FROM students
Retrieve students older than 18 years old:
SELECT name, age FROM students WHERE age > 18
Retrieve all information for a specific student:
SELECT * FROM students WHERE name = "John Doe"
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