How to use sql distinct

The SQL DISTINCT keyword removes duplicate rows by comparing all column values, leaving only unique rows. The usage includes the following steps: Specify the column name to select, followed by the DISTINCT keyword. Specifies the table name to query. DISTINCT can be applied to one or more columns. Unlike GROUP BY, DISTINCT directly removes duplicate rows without grouping.

SQL DISTINCT: Remove duplicate values

The SQL DISTINCT keyword is used to remove duplicate rows from query results, leaving only unique rows. It determines uniqueness by comparing all column values ​​for each row.

grammar

 <code class="sql">SELECT DISTINCT column_1, column_2, ... FROM table_name;</code>

in:

• column_1 , column_2 , ...: column name to select
• table_name : The table name to be queried

usage

The DISTINCT keyword can be applied to one or more columns. For example:

 <code class="sql">SELECT DISTINCT name FROM users;</code>

This query will select a unique name from the users table.

Differences from GROUP BY

Both DISTINCT and GROUP BY are used to remove duplicate values, but they work differently. GROUP BY Groups the results according to the specified column and then retains a representative row for each group. DISTINCT directly removes duplicate rows without any grouping.

Example

Table: products

id	name	price
1	MacBook Air	1000
2	iPhone 13	700
3	AirPods	150
4	MacBook Pro	1200
5	iPhone 13	700

Query:

 <code class="sql">SELECT DISTINCT name FROM products;</code>

result:

<code> ---------------- | name | ---------------- | MacBook Air | | iPhone 13 | | AirPods | | MacBook Pro | ----------------</code>

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