SQL IN

here are some additional clause in the SQL language that can be used to simplify queries by decrease the use of the single Operator repeatly. One of them is IN clause.

IN clause is used to simplify the queries if you want to select data that meet a large number of options. That means IN function helps reduce the need to use multiple OR conditions.

The SQL syntax for the IN operator is:

SELECT [COLUMN NAME] FROM [TABLE NAME]
WHERE [COLUMN] IN ( [VALUE LIST] )

EXAMPLE :

We would like to display all information in IT Department OR Marketing.

Table GameScores

PlayerName	Department	Scores
Jason	IT	3000
Irene	IT	1500
Jane	Marketing	1000
David	Marketing	2500
Paul	HR	2000
James	HR	2000

SQL statement :

SELECT * FROM GameScores
WHERE Department IN ('IT','Marketing')

Result:

PlayerName	Department	Scores
Jason	IT	3000
Irene	IT	1500
Jane	Marketing	1000
David	Marketing	2500

Actually, This SQL statement below also can show the same results.

SELECT * FROM GameScores
WHERE Department ='IT' OR Department ='Marketing'

Why we should use IN clause?
We should use IN comparisons instead of mutiple comparisons linked using OR whenever possible in order to improve maintainability of our queries. Adding additional value to an IN clause is much easier than repeatly the OR clauses. The code also easier to read as well.

巴特西

SQL IN

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