php - 按多个字段搜索。有时按一个字段，有时按多个字段

Question

我有搜索表单。在这里多个领域。有时我会提交一个字段，有时提交两个字段值，有时提交多个字段值。

     if (isset($_POST['search'])) {
        $projectName     = $_POST['pName'];
        $clientId      = $_POST['s_by_clientName'];
        $departmentId  = $_POST['s_by_department'];
        $statusName  = $_POST['s_by_status'];
        if (!empty($projectName)) 
        {
            $searchSql = mysql_query("select * from project_list where projectName='$projectName'");
        }

        if (!empty($clientId)) 
        {
            $searchSql = mysql_query("select * from project_list where client_id='$clientId'");
        }

        if (!empty($departmentId)) 
        {
            $searchSql = mysql_query("select * from project_list where department_id='$departmentId'");
        }

        if (!empty($statusName)) 
        {
            $searchSql = mysql_query("select * from project_list where status='$statusName'");
        }

    }

这些查询仅用于按单个字段搜索。 如何进行按一个或多个字段值执行搜索的查询 可能吗？？

Answer 1

在查询变量中使用串联

 $searchSql ="select * from project_list where 1=1 ";
 if (isset($_POST['search'])) {
    $projectName     = $_POST['pName'];
    $clientId      = $_POST['s_by_clientName'];
    $departmentId  = $_POST['s_by_department'];
    $statusName  = $_POST['s_by_status'];
    if (!empty($projectName)) 
    {
        $searchSql. = " AND projectName='$projectName'";
    }
    if (!empty($clientId)) 
    {
        $searchSql. = " AND client_id='$clientId'";
    }
    if (!empty($departmentId)) 
    {
        $searchSql. = " AND department_id='$departmentId'";
    }
    if (!empty($statusName)) 
    {
        $searchSql. = " AND status='$statusName'";
    }
}
$result=mysql_query($searchSql);

注意:mysql_query() 已在 PHP 5.5 中弃用并在 PHP 7 中删除。请更新以使用 PDO 的 mysqli 库。