Question

正如标题所示，我正在尝试使用单个查询来更新多个行，在两个不同的表中，其中id等于来自第三个表的select的结果。以下是样本表布局。

CREATE TABLE hampster_families (
    id INT(13) NOT NULL AUTO_INCREMENT,
    family_name varchar(255) NOT NULL UNIQUE,
    fuzzy_name varchar(255),
    tags varchar(255),
    date_added TIMESTAMP NOT NULL DEFAULT NOW(),
        PRIMARY KEY (id)

CREATE TABLE apple_addresses (
    id INT(13) NOT NULL AUTO_INCREMENT,
    address VARCHAR(39) NOT NULL UNIQUE,
    monitor BOOLEAN NOT NULL DEFAULT 0,
    date_added TIMESTAMP NOT NULL DEFAULT NOW(),
    hampster_family int(7) NOT NULL DEFAULT 0,
        PRIMARY KEY (id)

CREATE TABLE orange_addresses (
    id INT(13) NOT NULL AUTO_INCREMENT,
    address varchar(200) NOT NULL UNIQUE,
    monitor BOOLEAN NOT NULL DEFAULT 0,
    date_added TIMESTAMP NOT NULL DEFAULT NOW(),
    hampster_family INT(7) NOT NULl DEFAULT 0,
        PRIMARY KEY (id)

我正在尝试将orange_addresses.monitor，apple_addresses.monitor更新为等于1，其中orange_addresses.hampster_family，apple_addresses.hampster_family等于从SELECT id FROM hampster_families返回的id WHERE hampster_fammilies.family_name =“African Rabid”

我已经看过使用存储过的变量了，但是（我在这里缺乏SQL实力），因为这个查询需要一个变量，我不认为存储的变量会起作用。鉴于此，我已经考虑使用连接来实现这一点，但我从根本上误解了UPDATE / JOIN组合的语法。因此，我在这里寻找一些启示！：）

Answer 1

一步一步：这是您的基本查询：

 SELECT id 
 FROM hampster_families 
 WHERE hampster_fammilies.family_name = "African Rabid"

现在，你想要所有orange_addresses，其中orange_addresses.hampster_family是那个id，所以，JOIN：

 SELECT hampster_families.id 
 FROM hampster_families
 LEFT JOIN orange_adresses
     ON orange_addresses.hampster_family = hampster_families.id
 WHERE hampster_fammilies.family_name = "African Rabid"

apple_addresses也是如此：

 SELECT hampster_families.id 
 FROM hampster_families
 LEFT JOIN orange_adresses
     ON orange_addresses.hampster_family = hampster_families.id
 LEFT JOIN apple_adresses
     ON apple_addresses.hampster_family = hampster_families.id
 WHERE hampster_fammilies.family_name = "African Rabid"

我们对他们的监视列感兴趣

 SELECT orange_addresses.monitor, apple_addresses.monitor
 FROM hampster_families
 LEFT JOIN orange_adresses
     ON orange_addresses.hampster_family = hampster_families.id
 LEFT JOIN apple_adresses
     ON apple_addresses.hampster_family = hampster_families.id
 WHERE hampster_fammilies.family_name = "African Rabid"

使其更新：在设置后移动所选字段，使SELECT FROM UPDATE：

 UPDATE hampster_families
 LEFT JOIN orange_adresses
     ON orange_addresses.hampster_family = hampster_families.id
 LEFT JOIN apple_adresses
     ON apple_addresses.hampster_family = hampster_families.id
 SET 
   orange_addresses.monitor = 1
   apple_addresses.monitor  = 1
 WHERE hampster_fammilies.family_name = "African Rabid"

Answer 2

这对我有用。刚检查过。

UPDATE orange_addresses, apple_addresses
SET orange_addresses.monitor=1,apple_addresses.monitor=1
WHERE orange_addresses.hampster_family = apple_addresses.hampster_family
    AND orange_addresses.id = (
        SELECT id 
        FROM hampster_families 
        WHERE hampster_families.family_name = 'Test' 
        LIMIT 1);

MySQL更新两个表，其列与第三个表中的行相等

2 个答案: