Php 记录集的select语句存在问题

我正在和dreamweaver一起做一个项目，我的select语句遇到了问题。 我有这个

 SELECT *
    FROM client, `statement`
    WHERE client.client_id = `statement`.client_id

当我执行这个命令时，它会选择数据库中的所有人。所以我想在这个查询中添加另一个WHERE语句，这次是一个比较client.username和会话变量“MM_username”的语句

所以我在看这样的东西

SELECT *
    FROM client, `statement`
    WHERE client.client_id = `statement`.client_id  AND WHERE client.username = '$_SESSION['MM_Username']'

会话PHP代码如下所示

<?php
if (!isset($_SESSION)) {
  session_start();
}
$MM_authorizedUsers = "";
$MM_donotCheckaccess = "true";

// *** Restrict Access To Page: Grant or deny access to this page
function isAuthorized($strUsers, $strGroups, $UserName, $UserGroup) { 
  // For security, start by assuming the visitor is NOT authorized. 
  $isValid = False; 

  // When a visitor has logged into this site, the Session variable MM_Username set equal to their username. 
  // Therefore, we know that a user is NOT logged in if that Session variable is blank. 
  if (!empty($UserName)) { 
    // Besides being logged in, you may restrict access to only certain users based on an ID established when they login. 
    // Parse the strings into arrays. 
    $arrUsers = Explode(",", $strUsers); 
    $arrGroups = Explode(",", $strGroups); 
    if (in_array($UserName, $arrUsers)) { 
      $isValid = true; 
    } 
    // Or, you may restrict access to only certain users based on their username. 
    if (in_array($UserGroup, $arrGroups)) { 
      $isValid = true; 
    } 
    if (($strUsers == "") && true) { 
      $isValid = true; 
    } 
  } 
  return $isValid; 
}

$MM_restrictGoTo = "myflog.php";
if (!((isset($_SESSION['MM_Username'])) && (isAuthorized("",$MM_authorizedUsers, $_SESSION['MM_Username'], $_SESSION['MM_UserGroup'])))) {   
  $MM_qsChar = "?";
  $MM_referrer = $_SERVER['PHP_SELF'];
  if (strpos($MM_restrictGoTo, "?")) $MM_qsChar = "&";
  if (isset($_SERVER['QUERY_STRING']) && strlen($_SERVER['QUERY_STRING']) > 0) 
  $MM_referrer .= "?" . $_SERVER['QUERY_STRING'];
  $MM_restrictGoTo = $MM_restrictGoTo. $MM_qsChar . "accesscheck=" . urlencode($MM_referrer);
  header("Location: ". $MM_restrictGoTo); 
  exit;
}
?>

---

在的地方不应该有另一个

；将您的条件与
和
连接：

WHERE client.client_id = `statement`.client_id AND client.username = '$_SESSION['MM_Username']'

有关更多信息，请参阅您正在使用的SQL引擎的SQL语法定义，以了解
SELECT
查询的语法。
SELECT*
从客户端，
语句
其中client.client\u id=
语句
。client\u id和client.username='$'会话['MM\u username']

或
$user\u name=$\u会话['MM\u Username']；
挑选*
来自客户机c的语句s，其中c.client_id=s.client_id，c.username='$user_name'

请尝试此查询