need to find out count how many times 'a' used in a string using sql query

Question

@char ='abbhsaihuakkdjaiejjaklfdakdjdja'

Answer 1

一种方法使用len()和replace() ：

select (len(@char) - len(replace(@char, 'a', ''))) as num_a

Answer 2

You can also use DATALENGTH

DECLARE @tosearch VARCHAR(MAX)='a';
DECLARE @string VARCHAR(MAX)='abbhsaihuakkdjaiejjaklfdakdjdja';


SELECT (DATALENGTH(@string)-DATALENGTH(REPLACE(@string,@tosearch,'')))/DATALENGTH(@tosearch)  
AS a_count