How to Get First Character of a String in Sql?

I prefer:

SUBSTRING (my_column, 1, 1)

because it is Standard SQL-92 syntax and therefore more portable.

Strictly speaking, the standard version would be

SUBSTRING (my_column FROM 1 FOR 1)

The point is, transforming from one to the other, hence to any similar vendor variation, is trivial.

p.s. It was only recently pointed out to me that functions in standard SQL are deliberately contrary, by having parameters lists that are not the conventional commalists, in order to make them easily identifiable as being from the standard!

SUBSTRING ( MyColumn, 1 , 1 ) for the first character and SUBSTRING ( MyColumn, 1 , 2 ) for the first two.

SELECT SUBSTR(thatColumn, 1, 1) As NewColumn from student

It is simple to achieve by the following

DECLARE @SomeString NVARCHAR(20) = 'This is some string'
DECLARE @Result NVARCHAR(20)

Either

SET @Result = SUBSTRING(@SomeString, 2, 3)
SELECT @Result

@Result = his

or

SET @Result = LEFT(@SomeString, 6)
SELECT @Result

@Result = This i

INPUT

STRMIDDLENAME
--------------
Aravind Chaterjee
Shivakumar
Robin Van Parsee

SELECT STRMIDDLENAME, 
CASE WHEN INSTR(STRMIDDLENAME,' ',1,2) != 0 THEN SUBSTR(STRMIDDLENAME,1,1) || SUBSTR(STRMIDDLENAME,INSTR(STRMIDDLENAME,' ',1,1)+1,1)||
SUBSTR(STRMIDDLENAME,INSTR(STRMIDDLENAME,' ',1,2)+1,1)
WHEN INSTR(STRMIDDLENAME,' ',1,1) != 0 THEN SUBSTR(STRMIDDLENAME,1,1) || SUBSTR(STRMIDDLENAME,INSTR(STRMIDDLENAME,' ',1,1)+1,1)
ELSE SUBSTR(STRMIDDLENAME,1,1)
END AS FIRSTLETTERS
FROM Dual;

OUTPUT
STRMIDDLENAME                    FIRSTLETTERS
---------                        -----------------
Aravind Chaterjee                AC           
Shivakumar                       S
Robin Van Parsee                 RVP

If you search the first char of string in Sql string

SELECT CHARINDEX('char', 'my char')

=> return 4

Select First two Character in selected Field with Left(string,Number of Char in int)

SELECT LEFT(FName, 2) AS FirstName FROM dbo.NameMaster