How Can DISTINCT in SQL Help Me Select Only Unique Records?

Using DISTINCT in SQL for Unique Record Selection

Standard SQL SELECT * FROM table queries often return duplicate rows. To ensure data accuracy and efficient analysis, SQL provides the DISTINCT keyword. This allows you to retrieve only unique values from specified columns.

Illustrative Example:

Consider this sample table:

<code>| Column1 | Column2 | Column3 |
|---------|---------|---------|
| 1        | item1    | data1   |
| 2        | item1    | data2   |
| 3        | item2    | data3   |
| 4        | item3    | data4   |</code>

A SELECT * query would return all rows, including duplicates based on Column2.

To retrieve only unique rows, use the DISTINCT keyword:

<code class="language-sql">SELECT DISTINCT Column1, Column2, Column3
FROM table;</code>

This produces the following result, eliminating the duplicate item1 entry:

Column1	Column2	Column3
1	item1	data1
3	item2	data3
4	item3	data4

The DISTINCT keyword is a powerful tool for data cleaning and ensuring the accuracy of your SQL queries. It guarantees that only unique combinations of the specified columns are returned.

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