Question

我想解决的问题是，我想计算两个或更多表中相同用户名出现的次数。

我想要搜索的用户名需要从$_SESSION['username']

中选择

First Table
| id | username |  date |
| 1  |   Mart   |28-5-13|
| 2  |   farm   |27-5-13|
| 3  |   Mart   |29-5-13|

Second Table
| 1  |   Mart   |22-5-13|
| 1  |   Mart   |25-5-13|
| 1  |   farm   |24-5-13|

让我们看看$_SESSION['username'] = 'Mart'

如何统计两个表中出现相同用户名“Mart”的次数？

有点像吗？

$bloo = mysql_query('SELECT COUNT("username") FROM events AND Good WHERE username = "'.      mysql_real_escape_string($_SESSION['username']) . '"');
while ($row2 = mysql_fetch_array($bloo))

或者我走错了路？

任何帮助表示赞赏！谢谢

Answer 1

尝试使用first_table和second_table是您提到的2个表（“抱歉，1个数据库2表！”）：

SELECT
    SUM(c)
FROM (
    SELECT COUNT(*) as c FROM first_table WHERE username = 'Mart'
    UNION ALL
    SELECT COUNT(*) as c FROM second_table WHERE username = 'Mart'
) as tmp

Answer 2

所有数据库都在相同的服务器中？因为我认为分离服务器的最佳解决方案是使用Web服务......但如果不是，则只需要从两个查询中添加两个值。

Connect to multiple mysql DataBases

$dbh1 = mysql_connect($hostname, $username, $password); 
$dbh2 = mysql_connect($hostname, $username, $password, true); 

mysql_select_db('database1', $dbh1);
mysql_select_db('database2', $dbh2);

$res1 = mysql_query('select count(*) from tablename WHERE username="username"', $dbh1);
$res2 = mysql_query('select count(*) from tablename WHERE username="username', $dbh2);

$val1 = mysql_fetch_row($res1);
$val2 = mysql_fetch_row($res2);

$sum = $val1[0] + $val2[0];

基于$ _SESSION ['username']的MySQL，COUNT

2 个答案: