What is the usage of the SQL command “select”?

1 year ago
Liam
1 minute

The SELECT command is used to retrieve data from a database. Its basic syntax is as follows:

SELECT 列名或表达式
FROM 表名
WHERE 条件

Among them:

  1. Column name or expression: specifies the column or expression to be retrieved. It can be a single column name, multiple column names separated by commas, or a column containing a calculation expression.
  2. Table Name: Specifies the name of the table from which to retrieve data.
  3. Condition: Optional parameter used to restrict the search results, returning only the rows that meet the specified criteria.

例：Specific details were not provided in the report.

SELECT id, name, age
FROM students
WHERE age > 20

The command above retrieves the id, name, and age columns from a table named “students”, but only returns rows where the age is greater than 20.

bannerAds