Get all the values of a single column in a variable

Get all the values of a single column in a variable separated by comma.
DECLARE a Variable and set the Size of the variable according to your requirement. here in this code i have mentioned MAX.

Now Using

SELECT  @TempString =  @TempString + CityName +',' FROM Tbl_City

Statement we can append all the values in @TempString separated by comma.
@TempString will contain a extra comma at the end. so we need to remove that with the help of

SUBSTRING(@TempString,0,LEN(@TempString))

DECLARE @TempString VARCHAR(MAX)
SET @TempString = ''

SELECT  @TempString =  @TempString + CityName +',' FROM Tbl_City

SELECT SUBSTRING(@TempString,0,LEN(@TempString))