在选定字段中选择左前两个字符(字符串，int中的字符数)

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

通过以下方法很容易实现

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

要么

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

@Result = his

or

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

@Result = This i

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

第一个字符为SUBSTRING (MyColumn, 1,1)，前两个字符为SUBSTRING (MyColumn, 1,2)。

在选定字段中选择左前两个字符(字符串，int中的字符数)

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

输入

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