Which command is used for data retrieval in sql

The command used for data retrieval in SQL is the SELECT command, which allows the user to select specific data from a table. Syntax: SELECT column1, column2, ..., columnN FROM table_name [WHERE condition] [ORDER BY column_name [ASC | DESC]] [LIMIT row_count].

Commands used for data retrieval in SQL

The SELECT command is the basic command used for data retrieval in SQL . It allows users to select specific rows and columns of data from a database table.

Syntax

<code>SELECT column1, column2, ..., columnN
FROM table_name
[WHERE condition]
[ORDER BY column_name [ASC | DESC]]
[LIMIT row_count]</code>

Parameters

• ##column1, column2, ..., columnN:The column name to be retrieved.
• table_name: The name of the table to retrieve data.
• WHERE condition: (Optional) Condition for retrieving specific row data.
• ORDER BY column_name: (Optional) Sorts results based on a specific column. You can specify ASC (ascending order) or DESC (descending order).
• LIMIT row_count: (Optional) Limit the number of rows retrieved.

Example

<code>SELECT name, email
FROM customers
WHERE city = 'London'
ORDER BY name ASC
LIMIT 10;</code>

This query will select the names and email addresses of all London customers from a table called "customers", sorted by name in ascending order Sort the results and retrieve only the first 10 records.

Other Notes

The SELECT command can retrieve data from a single table or multiple tables.
• You can use the wildcard character
• * to retrieve data for all columns, such as SELECT * FROM table_name;.
Aggregation functions (such as
• SUM(), COUNT(), AVG()) can be used to summarize data.

The above is the detailed content of Which command is used for data retrieval in sql. For more information, please follow other related articles on the PHP Chinese website!