4. IF NOT EXISTS 执行INSERT INTO 也可以 加上else 执行其他语句
1、方法一 IF NOT EXISTS(SELECT * FROM TABLE_NAME WHERE FILED1 = 1 ) THEN INSERT INTO TABLE_NAME VALUES(1 2、将要插入的数据先写入临时表，然后用 INSERT INTO TABLE_NAME SELECT * FROM #TEMP_TABLE A LEFT JOIN TABLE_NAME ON A.FILED1 = B.FIELD1 WHERE B.FILED1 IS NULL ...
对于普通的 INSERT 插入,如果想要保证不插入重复记录,我们只有对某个字段创建唯一约束实现(比如:cardno卡号不能重复); 那有没有不创建唯一约束,仅通过 INSERT INTO 一条语句实现的方案呢? 答案:有的, INSERT INTO IF EXISTS 具体语法如下: INSERT INTO table(field1, field2, fieldn) SELECT 'field1', 'field...
So in short I insert new records with new "Appointment no" into "table 1" and the duplicate appointment no which already exist in table 1 , into table 1_copy. I could figure out the insert into if NOT EXISTS PART but am struggling to capture the dups and insert into...
Only inserting a row if it's not already there (7 answers) Closed 11 years ago. I would like to insert data into my database if one value doesn't exist in my database. I've got this code: try { SQLConnection.Open(); string sql = "INSERT INTO shop (title, price, information...
转SQL当记录不存在时插入insert if not exists 转自:http://blog.sina.com.cn/s/blog_5564eb640100i42t.html 插入(insert)一条记录很简单,但是一些特殊应用,在插入记录前,需要检查这条记录是否已经存在,只有当记录不存在时才执行插入操作,本文介绍的就是这个问题的解决方案。
if not exists(select * from Node where Nod_nodecode = '')用exists可以判断啊
sqlserver 判断是否存在,如果存在就update,不存在就insert if not exists(SELECT 1 from pr_equipmentFacility eq inner join pr_equipmentFacilityEx ex on eq.equipmentFacilityID = ex.equipmentFacilityID where eq.equipmentFacilityCode='对应编码') INSERT into pr_equipmentFacilityEx (equipmentFacilityID,brand,...
INSERT INTO Table2(Id, Name) SELECT Id, Name FROM Table1 但是,在我的情况下,可能存在重复的ID Table2(在我的情况下,它只是“ 1”),我不想再次复制该ID ,因为这会引发错误。 我可以这样写: IF NOT EXISTS(SELECT 1 FROM Table2 WHERE Id=1) INSERT INTO Table2 (Id, name) SELECT Id, name FR...
使用INSERT INTO … SELECT … FROM DUAL语句来实现批量插入数据,同时使用IF NOT EXISTS 来避免重复插入已存在的数据。 #批量插入数据sql = "INSERT INTO users (id, name) SELECT * FROM (SELECT %s, %s) AS tmp WHERE NOT EXISTS (SELECT id FROM users WHERE id = %s)" ...