Mysql的行合併

Question

我有這個表：

ip country 

1  A 
2  A 
3  B 
4  B 
4  B 

我想編寫一個查詢，這將返回類似：

A 1,2 
B 3,4 

例如SELECT * FROM table GROUP BY國家回報：

A 1 
B 3 

但這不是理想的結果。

Ι可以運行這個簡單的查詢：

SELECT * FROM table ORDER BY ip 

和編程會寫類似：

$c_ip=0; 
`while($row=mysql_fetch_array($result,MYSQL_ASSOC)){ 
if($row['ip'])!=$c_ip) 
{ 
$c_ip=$row['ip']; 
//new line!! 
}else 
{ 
//don't close <tr> code goes here 
} 
}` 

Answer 1

試試這個：

SELECT country, GROUP_CONCAT(DISTINCT ip SEPARATOR ',') AS ips 
FROM my_table 
GROUP BY country 

SQL Fiddle

Answer 2

試試這個Query，您可以在SQL SERVER

SELECT 
    t1.country, 
    STUFF((
    SELECT distinct ', ' + cast(t2.ip as varchar) 
    FROM Table1 t2 
    WHERE t2.country = t1.country 
    FOR XML PATH ('')) 
    ,1,2,'') AS Names 
FROM Table1 t1 
GROUP BY t1.country; 

SQL FIDDLE

Answer 3

使用STUFF試試這個：

SELECT country, GROUP_CONCAT(ip) 
FROM table1 
GROUP BY country 

SQL FIDDLE HERE

Answer 4

嘗試IP的這個

   SELECT DISTINCT country, SUBSTRING(ConcateColumn,2,LEN(ConcateColumn)) 
    FROM Table t1 
    CROSS APPLY ( 
       select substring((SELECT ',' + ip 
        FROM Table t2 
        WHERE t2.country = t2.country 
        ORDER BY DescOfFault 
        FOR XML PATH('')),2,20000) 
        ) D (ConcateColumn) 

Answer 5

您可能需要添加 'DISTINCT' 盈方，如果你不希望值4要重複做。

SELECT country, GROUP_CONCAT(DISTINCT ip SEPARATOR ',') AS ids 
FROM my_table 
GROUP BY country