Which command is used to implement data query in sql

In SQL, the command used for data query is SELECT, and the syntax is SELECT [column1, column2, ...] FROM table_name [WHERE condition] [ORDER BY ...] [LIMIT ...] , used to select specific columns, filter results, sort, and limit the number of rows.

Commands used to implement data query in SQL

In SQL, the commands used to implement data query areSELECT.

Syntax:

<code class="sql">SELECT [column1, column2, ...]
FROM table_name
[WHERE condition]
[ORDER BY ...]
[LIMIT ...]</code>

Parameters:

• ##column1, column2, ...: Column to select.
• table_name: The name of the table to be queried.
• WHERE condition: Optional condition used to filter results.
• ORDER BY: Used to sort the results by the specified column.
• LIMIT: Used to limit the number of rows in query results.

Example:

Select all records from the "employees" table:

<code class="sql">SELECT * FROM employees;</code>

Select "first_name" from the "employees" table and "salary" column, and sort according to the "salary" column in descending order:

<code class="sql">SELECT first_name, salary
FROM employees
ORDER BY salary DESC;</code>

Select all records with "age" greater than 30 from the "employees" table:

<code class="sql">SELECT * FROM employees
WHERE age > 30;</code>

From the "employees" table Select the first 10 records in:

<code class="sql">SELECT * FROM employees
LIMIT 10;</code>

Note:

The SELECT command is one of the most important commands in SQL and is used to retrieve and manipulate data.
• The column names in the query conditions must be valid columns in the table.
• The query result is a temporary table that can only be used in this session.

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