数据装载
数据的装载:
?SQL*LOADER
?外部表
?导入/导出
SQL*LOADER:
SQL*LOADER是一个ORACLE工具，能够将数据从外部数据文件装载到数据库中。
运行SQL*LOADER的命令是sqlldr。
Sqlldr的两种使用方式：
1. 只使用一个控制文件，在这个控制文件中包含数据
2. 使用一个控制文件(作为模板) 和一个数据文件
一般采用第二种方式，数据文件可以是 CSV 文件、txt文件或者以其他分割符分隔的。
说明：操作类型 可用以下中的一值：
1) insert --为缺省方式，在数据装载开始时要求表为空
2) append --在表中追加新记录
3) replace --删除旧记录(用 delete from table 语句)，替换成新装载的记录
4) truncate --删除旧记录(用 truncate table 语句)，替换成新装载的记录
| 通过spool来制作数据文件：--可以查询帮助文档的示例代码
SQL> spool /u01/app/oracle/test_data_loader/student.txt--开启spool导出数据文件 SQL> select id ||‘,‘ || name ||‘,‘ || age ||‘,‘ || inner_date from student;--导出数据 ID||‘,‘||NAME||‘,‘||AGE||‘,‘||INNER_DATE -------------------------------------------------------------------------------- 1,zhangsan,21,23-JAN-15 2,lisi,22,23-JAN-15 3,wangwu,23,23-JAN-15 SQL> spool off;--关闭 SQL> exit Disconnected from Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit Production With the Partitioning, OLAP, Data Mining and Real Application Testing options [[email protected] test_data_loader]$ cat student.txt--可以查看到导出的数据记录 SQL> select id ||‘,‘ || name ||‘,‘ || age ||‘,‘ || inner_date from student; ID||‘,‘||NAME||‘,‘||AGE||‘,‘||INNER_DATE -------------------------------------------------------------------------------- 1,zhangsan,21,23-JAN-15 2,lisi,22,23-JAN-15 3,wangwu,23,23-JAN-15 SQL> spool off; 写配置文件： [[email protected] test_data_loader]$ vi student.ctl [[email protected] test_data_loader]$ cat student.ctl options(skip=4)--表示前面的四行 load data--导入数据 infile ‘student.txt‘--通过该文件导入数据 into table student--导入的表 insert--执行的是插入操作 fields terminated by ‘,‘--记录中的分割符 ( id char,--注意虽然表中是number类型，但是要写char类型 name char, age char, inner_date date nullif (inner_date = "null")) [[email protected] test_data_loader]$ 既然是insert操作所以： SQL> truncate table student;--清空表，由于执行的是插入操作 Table truncated. SQL> select * from student; no rows selected 执行sqlldr操作： [[email protected] test_data_loader]$ sqlldr hr/hr control= student.ctl log = student.log SQL*Loader: Release 11.2.0.1.0 - Production on Fri Jan 23 23:11:08 2015 Copyright (c) 1982, 2009, Oracle and/or its affiliates. All rights reserved. Commit point reached - logical record count 4 [[email protected] test_data_loader]$ cat student.log SQL*Loader: Release 11.2.0.1.0 - Production on Fri Jan 23 23:11:08 2015 Copyright (c) 1982, 2009, Oracle and/or its affiliates. All rights reserved. Control File: student.ctl Data File: student.txt Bad File: student.bad Discard File: none specified (Allow all discards) Number to load: ALL Number to skip: 4 Errors allowed: 50 Bind array: 64 rows, maximum of 256000 bytes Continuation: none specified Path used: Conventional Table STUDENT, loaded from every logical record. Insert option in effect for this table: INSERT Column Name Position Len Term Encl Datatype ------------------------------ ---------- ----- ---- ---- --------------------- ID FIRST * , CHARACTER NAME NEXT * , CHARACTER AGE NEXT * , CHARACTER INNER_DATE NEXT * , DATE DD-MON-RR NULL if INNER_DATE = 0X6e756c6c(character ‘null‘) Record 4: Rejected - Error on table STUDENT, column ID. Column not found before end of logical record (use TRAILING NULLCOLS) Table STUDENT: 3 Rows successfully loaded. 1 Row not loaded due to data errors. 0 Rows not loaded because all WHEN clauses were failed. 0 Rows not loaded because all fields were null. Space allocated for bind array: 66048 bytes(64 rows) Read buffer bytes: 1048576 Total logical records skipped: 4 Total logical records read: 4 Total logical records rejected: 1 Total logical records discarded: 0 Run began on Fri Jan 23 23:11:08 2015 Run ended on Fri Jan 23 23:11:08 2015 Elapsed time was: 00:00:00.10 CPU time was: 00:00:00.01 [[email protected] test_data_loader]$ sqlplus hr/hr SQL*Plus: Release 11.2.0.1.0 Production on Fri Jan 23 23:13:14 2015 Copyright (c) 1982, 2009, Oracle. All rights reserved. Connected to: Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit Production With the Partitioning, OLAP, Data Mining and Real Application Testing options SQL> select * from student; ID NAME AGE INNER_DATE ---------- -------------------- ---------- ------------ 1 zhangsan 21 23-JAN-15 2 lisi 22 23-JAN-15 3 wangwu 23 23-JAN-15 SQL> exit |
外部表：
外部表中的数据不装入数据库中，数据库中只存储外部表的定义信息，实际的数据位于操作系统的平面文件中，
但是，可以在数据库中，像访问正常表那样，通过select语句来访问操作系统中的平面文件中所含有的数据。
外部表是只读的。
可以使用SQL，PL/SQL和JAVA访问外部表。
外表表分为2种：使用数据泵引擎生成的外部表、
|
SQL> create table student_re(re_id,re_name,re_age,re_inner_date) organization external ( type oracle_datapump--外部表生成方式是数据泵 default directory test_impdp_expdp--默认的路径 location(‘student.dmp‘)--通过路径和文件名生成外部表在操作系统的平面数据文件 ) parallel--并行 as select * from student; 2 3 4 5 6 7 8 9 10 Table created. SQL> !ls student.dmp STUENT_17109.log SQL> select * from stuent; RE_ID RE_NAME RE_AGE RE_INNER_DAT ---------- -------------------- ---------- ------------ 1 zhangsan 21 23-JAN-15 2 lisi 22 23-JAN-15 3 wangwu 23 23-JAN-15 SQL> |
根据文本文件创建的外部表。
| SQL> spool student.txt
ID||‘,‘||NAME||‘,‘||AGE||‘,‘||INNER_DATE -------------------------------------------------------------------------------- 1,zhangsan,21,23-JAN-15 2,lisi,22,23-JAN-15 3,wangwu,23,23-JAN-15 SQL> exit Disconnected from Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit Production With the Partitioning, OLAP, Data Mining and Real Application Testing options [[email protected] test_impdp_expdp]$ vi student.txt [[email protected] test_impdp_expdp]$ sqlplus hr/hr SQL*Plus: Release 11.2.0.1.0 Production on Sat Jan 24 00:05:18 2015 Copyright (c) 1982, 2009, Oracle. All rights reserved. Connected to: Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit Production With the Partitioning, OLAP, Data Mining and Real Application Testing options SQL> create table student_re_2--该外部表的名称下面列是外部表的建表语句，而上面通过数据泵的表是通过as select from tab来建立的。 2 (id number,name varchar2(20),age number(10),inner_date date) 3 organization external 4 ( type oracle_loader--外部文件方式 5 default directory test_impdp_expdp--默认的目录 6 access parameters--访问外部文件所遵守的格式 7 ( records delimited by newline--记录分隔符 fields terminated by ‘,‘--字段分隔符 8 ) location (‘student.txt‘)--位置 ); 9 10 11 Table created. SQL> select * from student_re_2; ID NAME AGE INNER_DATE ---------- -------------------- ---------- ------------ 1 zhangsan 21 23-JAN-15 2 lisi 22 23-JAN-15 3 wangwu 23 23-JAN-15 SQL> |