org.springframework.dao.DuplicateKeyException Exception thrown when an attempt to insert or update data results in violation of an primary key or unique constraint. Note that this is not necessarily a purely relational concept; unique primary keys ar
待总结 https://blog.csdn.net/JavaCoder_juejue/article/details/82313891 https://blog.csdn.net/a772304419/article/details/79669614 插入前,判断存不存在 https://www.cnblogs.com/luffe/p/7865316.html 1. ----------- 测试表及数据 ---------------- USE tempdb GO IF OBJECT_ID('A
在数据插入的时候,假设主键对应的值已经存在,则插入失败!这就是主键冲突.当主键存在冲突(duplicate key)的时候,可以选择性的进行处理,即忽略.更新或者替换. 1.忽略 insert ignore into table 保持原记录,忽略新插入的记录 2.替换 replace into table 替换原记录,即先删除原记录,再插入新的记录 3. 更新 insert into table value("xx","xx") ON DUPLICATE KEY U
mysql 插入数据唯一键冲突 前提: 修改数据三种可用的方法解决主键冲突的问题 1. insert into ... on duplicate key update set ... 2. update ... set = case key when ... then ... when ... then ... else end where ...; 3. replace into ... (与1相似,但若主键冲突会先删除原数据,后再插入新数据 ,所以运用时最好带上主键) 例: table :
update teacher set name ='111' where id in(286,289);print @@rowcount;--或select将查出,是@@rowcount,不是@rowcount或rowcount或其它 20181023 获取insert主键: select @@IDENTITY @@IDENTITY 列不能由用户直接更新,它是由系统自动维护的. 返回最后一个插入 IDENTITY 的值