嵌套查询 - 内部查询循环结束外部查询循环

Question

我有 2 个查询循环遍历它们的记录集以从内部循环提供输出。外部查询循环有几条记录，内部查询应该为每条记录触发。一旦内部循环运行，我只会得到外部查询循环的第一个 recoed。

我尝试将内部查询的 $result 命名为 $result2 并得到错误：sqlsrv_fetch_array(): 提供的资源不是有效的 ss_sqlsrv_stmt 资源。

// outer loop
$serverName = "livedata";
$connectionInfo = array( "Database"=>"ParishHomilyArchive", "UID"=>"ParishUser", "PWD"=>"P@\$\$word" );
$conn = sqlsrv_connect( $serverName, $connectionInfo);
if( $conn === false ) {
 die( print_r( sqlsrv_errors(), true));
}

if (isset($_REQUEST['Par_Num'])){
    $PN = $_REQUEST['Par_Num'];
}
else{
    $PN = 0;
}

$sql="SELECT Staff.StaffID, Staff.Name, Staff.Photo,     Staff_Position.StaffPage_ID, StaffPages.StaffPageName FROM parishStaff.dbo.StaffPages RIGHT JOIN (ParishStaff.dbo.Staff_Position RIGHT JOIN ParishStaff.dbo.Staff ON Staff_Position.Staff_ID = Staff.StaffID) ON StaffPages.StaffPageID = Staff_Position.StaffPage_ID WHERE (((Staff.par_Num)=" . $PN . ")) ORDER BY Staff.Name, StaffPages.StaffPageName;";



$stmt = sqlsrv_query( $conn, $sql);
if( $stmt === false ) {
     die( print_r( sqlsrv_errors(), true));
}

$result = sqlsrv_query($conn, $sql);

while($row = sqlsrv_fetch_array($result)) {

    //output outer loop stuff



    //inner loop
    $serverName = "livedata";
    $connectionInfo = array( "Database"=>"database", "UID"=>"User", "PWD"=>"password" );
    $conn = sqlsrv_connect( $serverName, $connectionInfo);
    if( $conn === false ) {
         die( print_r( sqlsrv_errors(), true));
    }

    if (isset($_REQUEST['Par_Num'])){
        $PN = $_REQUEST['Par_Num'];
    }
    else{
        $PN = 0;
    }

    $sql2="SELECT StaffPages.StaffPageID, StaffPages.StaffPageName FROM parishStaff.dbo.ParishPages INNER JOIN ParishStaff.dbo.StaffPages ON ParishPages.StaffPage_ID = StaffPages.StaffPageID WHERE (((ParishPages.Par_Num)=" . $PN . ") AND (Not (StaffPages.StaffPageID)=(SELECT StaffPages.StaffPageID FROM ParishStaff.dbo.StaffPages LEFT JOIN (ParishStaff.dbo.Staff_Position LEFT JOIN ParishStaff.dbo.Staff ON Staff_Position.Staff_ID = Staff.StaffID) ON StaffPages.StaffPageID = Staff_Position.StaffPage_ID WHERE (((Staff.StaffID)=" . $row['StaffID']. " )))));"; 

    $stmt = sqlsrv_query( $conn, $sql2);
    if( $stmt2 === false ) {
         die( print_r( sqlsrv_errors(), true));
    }
    $result = sqlsrv_query($conn, $sql2);

    while($row2 = sqlsrv_fetch_array($result)) {

        //output inner loop stuff

    }



}

我希望外循环在内循环的第一次迭代后不结束。

Answer 1

回答您的问题我稍微重新排列了您的代码，并在外循环结果集和内循环结果集上设置了不同的变量。我还删除了实际上无用的代码，例如：

$stmt = sqlsrv_query( $conn, $sql2);
if( $stmt2 === false ) {
     die( print_r( sqlsrv_errors(), true));
}
$result = sqlsrv_query($conn, $sql2);

Above 在$stmt 中创建一个结果集，然后在$result 中创建一个结果集。这里只需要调用一次sqlserver。

<?php
//This is BEFORE loop.. Just need to connect once
$serverName = "livedata";
$connectionInfo = array( "Database"=>"dbname", "UID"=>"user", "PWD"=>"password" );
$conn = sqlsrv_connect( $serverName, $connectionInfo);
if( $conn === false ) {
 die( print_r( sqlsrv_errors(), true));
}

if (isset($_REQUEST['Par_Num'])){
    $PN = $_REQUEST['Par_Num'];
}
else{
    $PN = 0;
}

$sql="{your SQL-statement}";
$result_outerloop = sqlsrv_query($conn, $sql);
if( $result_outerloop === false ) {
     die( print_r( sqlsrv_errors(), true));
}

while($row = sqlsrv_fetch_array($result_outerloop)) {

    $sql2="{your SQL-statement}"; 
    $result_innerresult = sqlsrv_query($conn, $sql2); //Not same variable as $result_outerloop
    if( $result_innerresult === false ) {
        die( print_r( sqlsrv_errors(), true));
    }

    while($row2 = sqlsrv_fetch_array($result_innerresult)) {
        //output inner loop stuff
    }

}

但正如@Sean Lange 指出的那样，SQL 本身根本不是好的做法。请阅读参数化查询。这实际上比按照你的方式做要容易得多。