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When filtering through the Where Clause during data reading from the database, the IN operator can check whether the column is within certain values.
Let’s make an example for a better understanding of the subject.
First, we create a table as below and add a few records to the table.
1 2 3 4 5 6 7 8 9 | USE [TestDB] GO CREATE TABLE [dbo].[MyTable]( [ID] [int] IDENTITY(1,1) NOT NULL, [Name] [varchar](50) NOT NULL, [Age] int NOT NULL ) ON [PRIMARY] GO INSERT INTO [dbo].[MyTable] VALUES ('Nurullah',34),('Faruk',27),('Hakan',36),('Ogun',27) |
Find people whose age is one of the values “25,26,27,28,29,30” :
1 | SELECT * FROM [dbo].[MyTable] WHERE Age IN(25,26,27,28,29,30) |
We can write the same query above with a subquery in the IN operator:
1 | SELECT * FROM [dbo].[MyTable] WHERE Age IN(SELECT AGE FROM [dbo].[MyTable] Where Age <=30 AND Age>=25) |
