Question

I have table like this:

-----------
ID | Value
-----------
1  | AAAA
2  | ABCD
3  | AADC
4  | ABBD

I am trying to figure out how to return the number of times a string occurs in each of the Value.

So, if I want to count of time 'A' and 'B'appears, the sql statement will return like this:

-------------------
ID | Value | Count
------------------- 
1  | AAAA  |   0 
2  | ABCD  |   1 
3  | AADC  |   0 
4  | ABBD  |   2 
5  | ABBB  |   3 
6  | AABB  |   3 
7  | AAAB  |   3

Is there any way to do this? I do not want to use php, vb, etc. Just MySQL

Answer 1

你可以尝试这个伴侣：

SELECT
    ID,
    Value,
    LENGTH(REPLACE(Value, 'A', '')) 'count_a',
    LENGTH(REPLACE(Value, 'B', '')) 'count_b'
FROM
    your_table;

或者这个：

SELECT
    ID,
    Value,
    LENGTH(REPLACE(Value, IF(LENGTH(REPLACE(Value, 'A','')) = 3, 'A', 'B'), '')) 'Count',
FROM
    your_table;

这是基于给定的预期结果

Answer 2

似乎您想要计算值，然后合并结果。我相信这样的事情对你有用。

SQLFiddle

SELECT 
    id,
    value,    
    ROUND (   
        (
            LENGTH(value)
            - LENGTH(REPLACE(value, "A", "")) 
        ) / LENGTH("A")        
    ) AS count    
FROM chars
UNION ALL
SELECT 
    id,
    value,    
    ROUND (   
        (
            LENGTH(value)
            - LENGTH(REPLACE(value, "B", "")) 
        ) / LENGTH("B")        
    ) AS count    
FROM chars

Count two or more repeated characters in a string

2 个答案: