MySQL 在 WHERE 子句中使用 if 条件时出现语法错误

Question

当我在 Mysql 查询的 WHERE 子句中使用 if 条件时出现语法错误。例如，如果我在 WHERE 1 中输入 sector = 2 这样的条件，它就可以工作。但是当我输入 if 条件时，它就不再起作用了。

$query= "SELECT 
   P.id
  ,P.price
  ,P.contract
  ,P.property_type
  ,P.sector
  ,P.title
  ,P.address
  ,P.bedrooms
  ,P.bathrooms
  ,P.price
  ,P.m2
  ,P.text_english
  ,P.photo_01
  ,P.utilities
  ,P.google_maps
  ,P.date


  ,CT.id
  ,CT.english_text
  ,PT.id
  ,PT.english
  ,C.cityname
  ,S.sectorname
  ,S.id
  ,O.ownername
  ,O.phone_one
  ,O.phone_two
  ,O.email
  ,O.notes

FROM properties P
JOIN contract CT
  ON CT.id = P.contract
JOIN property_type PT
  ON PT.id = P.property_type
JOIN city C
  ON C.id = P.city
JOIN sector S
  ON S.id = P.sector
JOIN owner O
  ON O.id = P.owner WHERE 1";           
            if (!empty($sector)) { $query .= "AND P.sector = '$sector'"; }
            if (!empty($property_type))  { $query .= " AND P.property_type = '$property_type'"; }
            if (!empty($contract))  { $query .= " AND P.contract = '$contract'"; }
            if (!empty($minimum_price))  { $query .= " AND P.price BETWEEN '$minimum_price' AND '$maximum_price'"; }
            if (!empty($m2_from))  { $query .= " AND P.m2 BETWEEN '$m2_from' AND '$m2_until'"; }
            if (!empty($bedrooms))  { $query .= " AND P.bedrooms = '$bedrooms'"; }

这是错误：

Fatal error: Uncaught exception 'PDOException' with message 'SQLSTATE[42000]: Syntax error or access violation: 1064 You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'P.sector = 2 LIMIT 0, 30' at line 43' in E:\xampp\htdocs\dolche\admin\class\pagination.php:451 Stack trace: #0 E:\xampp\htdocs\dolche\admin\class\pagination.php(451): PDOStatement->execute() #1 E:\xampp\htdocs\dolche\admin\search.php(190): pagination->execute() #2 {main} thrown in E:\xampp\htdocs\dolche\admin\class\pagination.php on line 451

非常欢迎任何解决此问题的帮助。谢谢！

Answer 1

您在 1 和 AND 之间缺少一个 space：

if (!empty($sector)) { $query .= "AND P.sector = '$sector'"; }
                                ^^^^
                                HERE

有趣的是，你在其他地方都做对了。

Answer 2

您必须在 AND 之前添加一个 space。

尝试：

if (!empty($sector)) { $query .= " AND P.sector = '$sector'"; }

而不是

if (!empty($sector)) { $query .= "AND P.sector = '$sector'"; }

Answer 3

在AND P.sector = '$sector'

前添加Space

变化自

if (!empty($sector)) { $query .= "AND P.sector = '$sector'"; }

到

if (!empty($sector)) { $query .= " AND P.sector = '$sector'"; }

Answer 4

请给出space：

ON O.id = P.owner WHERE 1 ";

或

if (!empty($sector)) { $query .= " AND P.sector = '$sector'"; }

MySQL 在 WHERE 子句中使用 if 条件时出现语法错误

MySQL syntax error on using if condition in WHERE clause

php

mysql

pdo

mysql-error-1064