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mysql - MySQL删除多个表上所有匹配记录的连接

问题描述

我创建了一个从 2 个表中删除的删除连接，但目前它只匹配并删除其中一个连接表中的第一条记录：

delete srid, rid from sub_region as srid
join statistics s
on srid.sub_region_id = s.sub_region_id
join region as rid
on rid.region_id = s.region_id
where s.region_id = 1;

region table:
id, region
1   america
2   mexico
3   canada

sub_region table:
id, sub_region
1   texas
2   new york

statistics table:
id, region_id, sub_region_id, text_description
1   1          1              texas has pretty good bbq
2   1          2              new york is a concrete jungle

我的查询将：1）删除统计表中的两条记录（因为我在 region 和 sub_region 上有一个外键，删除时级联）2）从匹配 region_id 的区域表中删除区域 3）只从 sub_region 表中删除 1 条记录

如果再次匹配统计表中的 region_id，我需要查询删除所有 sub_regions。

任何想法表示赞赏。

SQL：

-- -----------------------------------------------------
-- Table `region`
-- -----------------------------------------------------
CREATE TABLE IF NOT EXISTS `region` (
  `region_id` INT UNSIGNED NOT NULL AUTO_INCREMENT,
  `region` VARCHAR(255) NULL,
  PRIMARY KEY (`region_id`),
  UNIQUE INDEX `region_id_UNIQUE` (`region_id` ASC) VISIBLE,
  UNIQUE INDEX `region_UNIQUE` (`region` ASC) VISIBLE)
ENGINE = InnoDB;


-- -----------------------------------------------------
-- Table `sub_region`
-- -----------------------------------------------------
CREATE TABLE IF NOT EXISTS `sub_region` (
  `sub_region_id` INT UNSIGNED NOT NULL AUTO_INCREMENT,
  `sub_region` VARCHAR(255) NULL,
  PRIMARY KEY (`sub_region_id`),
  UNIQUE INDEX `sub_region_id_UNIQUE` (`sub_region_id` ASC) VISIBLE,
  UNIQUE INDEX `sub_region_UNIQUE` (`sub_region` ASC) VISIBLE)
ENGINE = InnoDB;


-- -----------------------------------------------------
-- Table `statistics`
-- -----------------------------------------------------
CREATE TABLE IF NOT EXISTS `statistics` (
  `statistics_id` INT UNSIGNED NOT NULL AUTO_INCREMENT,
  `region_id` INT UNSIGNED NULL,
  `sub_region_id` INT UNSIGNED NULL,
  `text_description` VARCHAR(255) NULL,
  PRIMARY KEY (`statistics_id`),
  UNIQUE INDEX `statistics_id_UNIQUE` (`statistics_id` ASC) VISIBLE,
  INDEX `fk_region_statistics_idx` (`region_id` ASC) VISIBLE,
  INDEX `fk_sub_region_statistics_idx` (`sub_region_id` ASC) VISIBLE,
  CONSTRAINT `fk_region_statistics`
    FOREIGN KEY (`region_id`)
    REFERENCES `region` (`region_id`)
    ON DELETE CASCADE
    ON UPDATE NO ACTION,
  CONSTRAINT `fk_sub_region_statistics`
    FOREIGN KEY (`sub_region_id`)
    REFERENCES `sub_region` (`sub_region_id`)
    ON DELETE CASCADE
    ON UPDATE NO ACTION)
ENGINE = InnoDB;

标签： mysqlsql

解决方案

您必须在删除之前禁用外键检查才能获得所需的结果。

SET @@foreign_key_checks := 0;

DELETE region, sub_region
FROM statistics
JOIN region USING (region_id)
JOIN sub_region USING (sub_region_id)
WHERE region_id = 1;

SET @@foreign_key_checks := 1;

见小提琴

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