如何在Wordpress中连接多个表获取数据

Question

if(isset($_POST['search'])){
    $mls=$_POST['mls_number'];
    $sql = "SELECT * FROM listing_master_residential
     , listing_master_condo 
    , listing_master_commercial  
    INNER JOIN listing_master_residential AS res ON res.Ml_num=Ml_num
    INNER JOIN listing_master_condo AS con ON con.Ml_num=Ml_num
    INNER JOIN listing_master_commercial AS com ON com.Ml_num=Ml_num
     WHERE Ml_num='$mls'";
    $result = $wpdb->get_results($sql) or die(mysql_error());
    foreach( $result as $row){
        echo $row->Lot_code."<br/>";
        echo $row->Ml_num."<br/>";
        echo $row->Acres;
        echo $row->Addr."<br/>";
        echo $row->Bath_tot;
        echo $row->Br;
        echo $row->Br_plus;
    }

}

 }

请检查我的代码，他们显示错误代码

where子句中的“ Ml_num”列不明确

预先谢谢您，请帮助我..我错了吗？

Answer 1

尝试这个

 $sql = "SELECT * FROM listing_master_residential AS res
       INNER JOIN listing_master_condo AS con ON con.Ml_num=res.Ml_num
       INNER JOIN listing_master_commercial AS com ON com.Ml_num=con.Ml_num    
       WHERE res.Ml_num='$mls'";

Answer 2

$ sql =“ SELECT * FROM listing_master_residential ，listing_master_condo，listing_master_commercial
INNER JOIN listing_master_residential AS res ON res.Ml_num = Ml_num INNER JOIN Listing_master_condo AS con ON CON.Ml_num = Ml_num INNER JOIN listing_master_commercial AS com ON com.Ml_num = Ml_num WHERE Ml_num ='$ mls'“;

这里有几个错误：

1. 您尝试对同一表使用多种类型的联接：表名之间的（“，”表示您尝试进行CROSS JOIN）

2. 正如MySQL告诉您的那样，列Ml_num含义不明确（您应在每个使用table_name.Ml_num的地方使用它。

   $sql = "SELECT * FROM listing_master_residential AS lmr INNER JOIN listing_master_residential AS res ON res.Ml_num=lmr.Ml_num INNER JOIN listing_master_condo AS con ON con.Ml_num=lmr.Ml_num INNER JOIN listing_master_commercial AS com ON com.Ml_num=lmr.Ml_num WHERE lmr.Ml_num='$mls'";

我认为这应该有效。