How do I store the select column in a variable?

Question

How do I store the select column in a variable?

I tried this, but it throws me an error "Incorrect syntax":

declare @EmpId int
SELECT  dbo.Employee.Id as @EmpId FROM  dbo.Employee

Answer 1

select @EmpID = ID from dbo.Employee

Or

set @EmpID =(select id from dbo.Employee)

Note that the select query might return more than one value or rows. so you can write a select query that must return one row.

If you would like to add more columns to one variable(MS SQL), there is an option to use table defined variable

DECLARE @sampleTable TABLE(column1 type1)
INSERT INTO @sampleTable
SELECT columnsNumberEqualInsampleTable FROM .. WHERE ..

As table type variable do not exist in Oracle and others, you would have to define it:

DECLARE TYPE type_name IS TABLE OF (column_type | variable%TYPE | table.column%TYPE [NOT NULL] INDEX BY BINARY INTEGER;

-- Then to declare a TABLE variable of this type: variable_name type_name;

-- Assigning values to a TABLE variable: variable_name(n).field_name := 'some text';

-- Where 'n' is the index value

Answer 2

Assuming such a query would return a single row, you could use either

select @EmpId = Id from dbo.Employee

Or

set @EmpId = (select Id from dbo.Employee)

Answer 3

This is how to assign a value to a variable:

SELECT @EmpID = Id
  FROM dbo.Employee

However, the above query is returning more than one value. You'll need to add a WHERE clause in order to return a single Id value.