Question

我的应用程序使用PHP 5.5和MS SQL从数据库和显示中查询某些记录。在SQL服务器上运行时，此查询大约需要2分钟才能执行。

我的问题是mssql_query()有时会返回NOTHING（即既没有资源ID也没有真或假）。

我预感到这个问题是由于MS SQL超时引起的，但是我没有证明这一点，因为我在php.ini文件中配置了mssql.timeout = 300（秒）。

有人能帮助我找到根本原因吗？我是php的新手。

SQL查询：

SET TRANSACTION ISOLATION LEVEL READ UNCOMMITTED;

SELECT 
    *
FROM table1 latest
LEFT OUTER JOIN table1 successful 
ON latest.MachineVersionID = successful.MachineVersionID
 AND successful.BackupToken = (
    SELECT TOP 1 BackupToken
    FROM table1
    WHERE MachineVersionID = successful.MachineVersionID
    AND BackupState = 7 AND IsPartial = 0
    ORDER BY EndTime DESC
)
INNER JOIN table2 mv ON latest.MachineVersionID = mv.MachineVersionID
INNER JOIN table3 m ON mv.MachineID = m.MachineID
INNER JOIN table4 c ON m.ClientID = c.ClientID
WHERE latest.BackupToken = (
    SELECT TOP 1 BackupToken
    FROM table1
    WHERE MachineVersionID = latest.MachineVersionID
    ORDER BY EndTime DESC
)
AND c.PartnerID in (1,2,3,4,5,....)
ORDER BY latest.MachineVersionID

mssql_query什么都不返回

0 个答案: