sql：insert into table 与 insert overwrite table 区别

2023-07-28 05:24| 来源: 网络整理| 查看: 265

创建测试表，来测试看看测试结果：

create table test(name string,pwd string,createdate string)row format delimited fields terminated by ',';

第一步：使用insert into 插入数据到表中：

insert into test(name,pwd,createdate)values('name1','pwd1','2017-06-20 14:14:09'); insert into test(name,pwd,createdate)values('name1','pwd1','2017-06-20 14:14:09'); insert into test(name,pwd,createdate)values('name2','pwd2','2017-06-20 14:14:09'); insert into test(name,pwd,createdate)values('name2','pwd2','2017-06-20 14:14:09'); 0: jdbc:hive2://10.78.152.52:21066/> select * from test; +------------+-----------+----------------------+--+ | test.name | test.pwd | test.createdate | +------------+-----------+----------------------+--+ | name1 | pwd1 | 2017-06-20 14:14:09 | | name1 | pwd1 | 2017-06-20 14:14:09 | | name2 | pwd2 | 2017-06-20 14:14:09 | | name2 | pwd2 | 2017-06-20 14:14:09 | +------------+-----------+----------------------+--

第二步：不清理以上插入的记录，直接执行insert overwirte，并查询分析结果：

insert overwrite table test select 'name1' as name,'pwd1' as pwd,'2017-06-20 14:14:09' as createdate; insert overwrite table test select 'name2' as name,'pwd2' as pwd,'2017-06-20 14:14:09' as createdate; insert overwrite table test select 'name2' as name,'pwd2' as pwd,'2017-06-20 14:14:09' as createdate; insert overwrite table test select 'name3' as name,'pwd3' as pwd,'2017-06-20 14:14:09' as createdate; 0: jdbc:hive2://10.78.152.62:21066/> select * from test; +------------+-----------+----------------------+--+ | test.name | test.pwd | test.createdate | +------------+-----------+----------------------+--+ | name3 | pwd3 | 2017-06-20 14:14:09 | +------------+-----------+----------------------+--+

第三步：不清理上边步骤执行后的结果，接着执行以下sql语句，并查询结果：

insert overwrite table test select 'name2' as name,'pwd2' as pwd,'2017-06-20 14:14:09' as createdate; 0: jdbc:hive2://10.78.152.62:21066/> select * from test; +------------+-----------+----------------------+--+ | test.name | test.pwd | test.createdate | +------------+-----------+----------------------+--+ | name2 | pwd2 | 2017-06-20 14:14:09 | +------------+-----------+----------------------+--+

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