Which statement is used to implement data retrieval in sql

The SELECT statement is the main statement used for data retrieval in SQL. The syntax is: SELECT [column name] FROM [table name] [condition] [grouping] [condition] [sort]. Examples include retrieving names and scores from the students table, retrieving orders with a price greater than 100 from the orders table, and retrieving total products from the products table grouped by quantity and displaying only the grouped totals greater than 50.

Statements to implement data retrieval in SQL

In SQL, the main statement to implement data retrieval isSELECT.

SELECT statement is used to extract data from a database table. Its basic syntax is as follows:

<code>SELECT [列名或表达式]
FROM [表名]
[WHERE 条件]
[GROUP BY 分组列]
[HAVING 分组条件]
[ORDER BY 排序列]</code>

where:

• [ Column name or expression]: Specify the column or calculated expression to be retrieved.
• [Table name]: Specify the table to retrieve data from.
• [WHERE condition]: Specify the conditions for retrieving data.
• [GROUP BY grouping column]: Group the results according to the specified column.
• [HAVING grouping conditions]: Apply conditions to grouped data.
• [ORDER BY sort column]: Sort the results by the specified column.

Example

The following example retrieves the names and scores of all students from the students table:

<code>SELECT name, score
FROM students;</code>

below Example retrieves all orders with a price greater than 100 from the orders table:

<code>SELECT *
FROM orders
WHERE price > 100;</code>

The following example retrieves the total number of products grouped by quantity from the products table and displays only Groups with total number greater than 50:

<code>SELECT product_id, SUM(quantity) AS total_quantity
FROM products
GROUP BY product_id
HAVING total_quantity > 50;</code>

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