案例：当你删除的表数据包含外键，关联其他表数据时。删除当前数据，会造成其他数据成为“孤儿”,可能会造成数据混乱。因此我们需要再MySQL中进行外键约束

具体的SQL语句：

SET NAMES utf8mb4;
SET FOREIGN_KEY_CHECKS = 0;

-- ----------------------------
-- Table structure for tb_node
-- ----------------------------
DROP TABLE IF EXISTS `tb_node`;
CREATE TABLE `tb_node`  (
  `id` int(11) NOT NULL AUTO_INCREMENT COMMENT '主键Id',
  `region_id` int(11) NOT NULL COMMENT '区域Id',
  `partner_id` int(11) NOT NULL COMMENT '合作商Id',
  `node_name` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NULL DEFAULT NULL COMMENT '区域名称',
  `address` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NULL DEFAULT NULL COMMENT '详细地址',
  `business_type` int(11) NULL DEFAULT NULL COMMENT '商圈类型',
  `remark` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NULL DEFAULT NULL COMMENT '备注',
  `create_by` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NULL DEFAULT NULL COMMENT '创建人',
  `update_by` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NULL DEFAULT NULL COMMENT '更新人',
  `create_time` datetime NULL DEFAULT NULL COMMENT '创建时间',
  `update_time` datetime NULL DEFAULT NULL COMMENT '更新时间',
  PRIMARY KEY (`id`) USING BTREE,
  INDEX `区域Id`(`region_id`) USING BTREE,
  INDEX `合作商Id`(`partner_id`) USING BTREE,
  CONSTRAINT `区域Id` FOREIGN KEY (`region_id`) REFERENCES `tb_region` (`id`) ON DELETE RESTRICT ON UPDATE RESTRICT,
  CONSTRAINT `合作商Id` FOREIGN KEY (`partner_id`) REFERENCES `tb_partner` (`id`) ON DELETE RESTRICT ON UPDATE RESTRICT
) ENGINE = InnoDB AUTO_INCREMENT = 5 CHARACTER SET = utf8mb4 COLLATE = utf8mb4_general_ci COMMENT = '点位表' ROW_FORMAT = DYNAMIC;

SET FOREIGN_KEY_CHECKS = 1;

 在ruoYi的前后端分离框架中，捕获异常：

package com.dkd.framework.web.exception;

import javax.servlet.http.HttpServletRequest;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.dao.DataIntegrityViolationException;
import org.springframework.security.access.AccessDeniedException;
import org.springframework.validation.BindException;
import org.springframework.web.HttpRequestMethodNotSupportedException;
import org.springframework.web.bind.MethodArgumentNotValidException;
import org.springframework.web.bind.MissingPathVariableException;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RestControllerAdvice;
import org.springframework.web.method.annotation.MethodArgumentTypeMismatchException;
import com.dkd.common.constant.HttpStatus;
import com.dkd.common.core.domain.AjaxResult;
import com.dkd.common.exception.DemoModeException;
import com.dkd.common.exception.ServiceException;
import com.dkd.common.utils.StringUtils;

/**
 * 全局异常处理器
 * 
 * @author ruoyi
 */
@RestControllerAdvice
public class GlobalExceptionHandler
{
    private static final Logger log = LoggerFactory.getLogger(GlobalExceptionHandler.class);

    /**
     * 数据完整性异常
     */
    @ExceptionHandler(DataIntegrityViolationException.class)
    public AjaxResult handleDataIntegrityViolationException(DataIntegrityViolationException e)
    {
        log.error(e.getMessage(), e);
        if (StringUtils.containsIgnoreCase(e.getMessage(), "Duplicate entry"))
        {
            return AjaxResult.error("数据已存在");
        }
        if(StringUtils.containsIgnoreCase(e.getMessage(), "foreign")){
            return AjaxResult.error("无法删除，有其他数据引用！");
        }
        return AjaxResult.error("数据完整性异常，请检查数据是否完整");
    }
}

再次点击删除：