SQL indexOf、lastIndexOf

DECLARE @Name NVARCHAR (50)
SET @Name = 'abcd.12345.efght'

DECLARE @Position INT

--sql first indexof
SET @Position = CHARINDEX('.', @Name);
SELECT SUBSTRING (@Name, 0,@Position)--abcd

--sql last indexof
SET @Position = LEN(@Name) - CHARINDEX('.', REVERSE(@Name)) + 1
SELECT SUBSTRING (@Name, @Position+1,len(@Name)-@Position+1) --efght