database - Drupal 7 - 查询中的多个连接给我带来了麻烦

Question

将新字段添加到 Drupal 站点的用户注册页面时，新字段不会存储在“用户”表中，而是存储在它们自己的单独表中。我设置了一个自定义表单模块页面，用户可以根据年龄、性别、是否是学生以及是否选择以“Live”名义接收消息来选择哪些人接收消息。我以前从未在 mySQL 查询中使用过“join”，因此我不确定 Drupal 数据库 API 的适当语法是什么。这是我目前拥有的:

$query = db_select("field_data_field_age", "a");
$query->join("field_data_field_gender", "g", "a.entity_id = g.entity_id");
$query->join("field_data_field_phone_number", "p", "a.entity_id = p.entity_id AND g.entity_id = p.entity_id");
$query->join("field_data_field_student", "s", "a.entity_id = s.entity_id AND g.entity_id = s.entity_id AND p.entity_id = s.entity_id");
$query->join("field_data_field_live", "l", "a.entity_id = l.entity_id AND g.entity_id = l.entity_id AND p.entity_id = l.entity_id AND s.entity_id = l.entity_id");
$query->groupBy("p.entity_id");
$query->fields("p", array("field_phone_number_value"))
    ->condition("a.field_age_value", $values["age_lower"], >=)
    ->condition("a.field_age_value", $values["age_upper"], <=)
    ->condition("l.field_live_value", "Yes", =)
    ->condition("g.field_gender_value", values["gender"], =);

$phone_numbers = $query->execute();

这段代码破坏了我的网站，我不确定我做错了什么。再次，我尝试在“multiple joins mysql”下搜索 Google，但没有找到任何专门处理 Drupal 数据库 API 的内容。任何帮助将不胜感激，谢谢!

Answer 1

倒数第三行的“values”变量上缺少 $。

此外，运算符 >=、<= 和 = 必须是字符串(用引号引起来)。