小编给大家分享一下数据库中批量插入数据时主键冲突怎么办，希望大家阅读完这篇文章之后都有所收获，下面让我们一起去探讨吧！
客户有这样一个需求：有一个大表A，有主键，经常需要往这个表中批量插入大量数据，但插入的数据可能自身重复或者跟表A重复。
下面测试几种插入的方法：
DB:ORACLE 11.2.0.4
新建测试表：
新建表scott.tb_01
create table scott.tb_01
as
SELECT level c1,level c2,level c3
FROM DUAL
CONNECT BY LEVEL <= 100000;
在表scott.tb_01上增加主键
create unique index scott.pk_tb_01 on scott.tb_01(c1); --这一步不是必需的，因为下一步会自动建索引，但这种建索引再加主键的方式可以在建索引的时候加并行。
alter table scott.tb_01 add constraint pk_tb_01 primary key (c1) using index;
新建表scott.tb_02
create table scott.tb_02
as
SELECT level+100000 c1,level c2,level c3
FROM DUAL
CONNECT BY LEVEL <= 100000;
在表scott.tb_02上插入表scott.tb_01的100条数据做为重复数据
insert into scott.tb_02
SELECT c1,c2, c3
FROM scott.tb_01
where rownum <= 100;
commit;
现在需要将表scott.tb_02中和表scott.tb_01非重复的数据插入到scott.tb_01
方法1：关联插入
INSERT INTO SCOTT.TB_01
SELECT A.* --这里如果表SCOTT.TB_02自身有重复数据，还要加上distinct
FROM SCOTT.TB_02 A
LEFT JOIN SCOTT.TB_01 B
ON A.c1 = B.c2
WHERE B.c1 IS NULL;
100000 rows created.
上面一种常见的插入方法，这个方法的的问题在于，如果表SCOTT.TB_02和表SCOTT.TB_01都很大，两个表关联查询的成本会很高，影响性能。
方法2：使用HINT:IGNORE_ROW_ON_DUPKEY_INDEX
不使用HINT:
INSERT
INTO SCOTT.TB_01
SELECT * FROM SCOTT.TB_02 ;
ERROR at line 1:
ORA-00001: unique constraint (SCOTT.PK_TB_01) violated
从上面可以看出直接将表SCOTT.TB_02插入到表SCOTT.TB_01会出现主键冲突，报ORA-00001错误。
使用HINT:
INSERT
INTO SCOTT.TB_01 A
SELECT * FROM SCOTT.TB_02 ;
100000 rows created.
从上面可以看出，加上HINT后，表SCOTT.TB_02中和表SCOTT.TB_01没有主键冲突的记录插入到表SCOTT.TB_01中，冲突的100条记录没有插入，也没有报错。
方法3：使用impdp的skip_constraint_errors选项
创建dump目录
create directory dump_home as '/home/oracle';
导出表scott.tb_02
expdp system tables=scott.tb_02 directory=dump_home dumpfile=expdp_tb_02.dmp logfile=expdp_tb_02.log
使用expdp导出表scott.tb_02，用于后续导入到表scott.tb_01中。
导入表scott.tb_02到scott.tb_01，不加skip_constraint_errors选项
impdp system tables=scott.tb_02 remap_table=scott.tb_02:tb_01 content=data_only directory=dump_home dumpfile=expdp_tb_02.dmp logfile=impdp_tb_02.log
Import: Release 11.2.0.4.0 - Production on Tue Dec 5 23:18:49 2017
Copyright (c) 1982, 2011, Oracle and/or its affiliates. All rights reserved.
Password:
Connected to: Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options
Master table "SYSTEM"."SYS_IMPORT_TABLE_01" successfully loaded/unloaded
Starting "SYSTEM"."SYS_IMPORT_TABLE_01": system/******** tables=scott.tb_02 remap_table=scott.tb_02:tb_01 content=data_only directory=dump_home dumpfile=expdp_tb_02.dmp logfile=impdp_tb_02.log
Processing object type TABLE_EXPORT/TABLE/TABLE_DATA
ORA-31693: Table data object "SCOTT"."TB_01" failed to load/unload and is being skipped due to error:
ORA-00001: unique constraint (SCOTT.PK_TB_01) violated
Job "SYSTEM"."SYS_IMPORT_TABLE_01" completed with 1 error(s) at Tue Dec 5 23:19:02 2017 elapsed 0 00:00:09
从上面可以看出，如果不加skip_constraint_errors选项就会报主键冲突错误，导入失败。
导入表scott.tb_02到scott.tb_01，加skip_constraint_errors选项
impdp system tables=scott.tb_02 remap_table=scott.tb_02:tb_01 content=data_only directory=dump_home dumpfile=expdp_tb_02.dmp logfile=impdp_tb_02.log data_options=skip_constraint_errors
Import: Release 11.2.0.4.0 - Production on Tue Dec 5 23:21:29 2017
Copyright (c) 1982, 2011, Oracle and/or its affiliates. All rights reserved.
Password:
Connected to: Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options
Master table "SYSTEM"."SYS_IMPORT_TABLE_01" successfully loaded/unloaded
Starting "SYSTEM"."SYS_IMPORT_TABLE_01": system/******** tables=scott.tb_02 remap_table=scott.tb_02:tb_01 content=data_only directory=dump_home dumpfile=expdp_tb_02.dmp logfile=impdp_tb_02.log data_options=skip_constraint_errors
Processing object type TABLE_EXPORT/TABLE/TABLE_DATA
. . imported "SCOTT"."TB_01" 1.796 MB 100000 out of 100100 rows
100 row(s) were rejected with the following error:
ORA-00001: unique constraint (SCOTT.PK_TB_01) violated
Rejected rows with the primary keys are:
Rejected row #1:
column C1: 1
…
Rejected row #99:
column C1: 99
Rejected row #100:
column C1: 100
Job "SYSTEM"."SYS_IMPORT_TABLE_01" successfully completed at Tue Dec 5 23:21:56 2017 elapsed 0 00:00:23
从上面可以看出，导入顺利完成，并跳过了主键冲突的行，并在impdp的log中显示行的信息。
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