Oracle数据加载和卸载的实现方法_Oracle

在日常工作中；经常会遇到这样的需求：

Oracle 数据表跟文本或者文件格式进行交互；即将指定文件内容导入对应的 Oracle 数据表中；或者从 Oracle 数据表导出。
其他数据库中的表跟Oracle数据库进行交互。

　　若是少量数据；可选择的解决方案有很多。常用的用 Pl/SQL developer工具，或者手动转换为 INSERT 语句，或者通过API。但数据量大；用上面的方法效率太烂了。本文来说说 Oracle 数据的加载和卸载。

Oracle中的DBLINK
Oracle加载数据-外部表
Oracle加载数据-sqlldr工具
Oracle卸载数据-sqludr

一. Oracle 中的 DBLINK

　　在日常工作中；会遇到不同的数据库进行数据对接；每个数据库都有着功能；像Oracle有 DBLINK ; PostgreSQL有外部表。

1.1 Oracle DBlink 语法

CREATE [PUBLIC] DATABASE LINK link
CONNECT TO username
IDENTIFIED BY password
USING 'connectstring'

1.2 Oracle To Mysql

　　在oracle配置mysql数据库的dblink

二.Oracle加载数据-外部表

　　ORACLE外部表用来存取数据库以外的文本文件（Text File）或ORACLE专属格式文件。因此，建立外部表时不会产生段、区、数据块等存储结构，只有与表相关的定义放在数据字典中。外部表，顾名思义，存储在数据库外面的表。当存取时才能从ORACLE专属格式文件中取得数据，外部表仅供查询，不能对外部表的内容进行修改（INSERT、UPDATE、DELETE操作）。不能对外部表建立索引。

2.1 创建外部表需要的目录

				?

									# 创建外部表需要的目录

									SQL> create or replace directory DUMP_DIR as '/data/ora_ext_lottu'; 

									Directory created.

									# 给用户授予指定目录的操作权限

									SQL> GRANT READ,WRITE ON DIRECTORY DUMP_DIR TO lottu;

									Grant succeeded.

2.2 外部表源文件lottu.txt

				?

									10,ACCOUNTING,NEW YORK

									20,RESEARCH,DALLAS

									30,SALES,CHICAGO

									40,OPERATIONS,BOSTON

2.3 创建外部表

				?

									drop table dept_external purge;

									CREATE TABLE dept_external (

									  deptno   NUMBER(6),

									  dname   VARCHAR2(20),

									  loc    VARCHAR2(25) 

									)

									ORGANIZATION EXTERNAL

									(TYPE oracle_loader

									 DEFAULT DIRECTORY DUMP_DIR

									 ACCESS PARAMETERS

									 (

									 RECORDS DELIMITED BY newline

									 BADFILE 'lottu.bad'

									 LOGFILE 'lottu.log'

									 FIELDS TERMINATED BY "," OPTIONALLY ENCLOSED BY '"'

									 (

									  deptno   INTEGER EXTERNAL(6),

									  dname   CHAR(20),

									  loc    CHAR(25)

									 )

									 )

									 LOCATION ('lottu.txt')

									)

									REJECT LIMIT UNLIMITED;

查看数据

				?

									SQL> select * from dept_external;

									  DEPTNO DNAME LOC

									---------- -------------------- -------------------------

									 10 ACCOUNTING NEW YORK

									 20 RESEARCH DALLAS

									 30 SALES CHICAGO

									 40 OPERATIONS BOSTON

三. Oracle加载数据-sqlldr工具

3.1 准备实验对象

　　创建文件lottu.txt；和表tbl_load_01。

				?

									[oracle@oracle235 ~]$ seq 1000|awk -vOFS="," '{print $1,"lottu",systime()-$1}' > lottu.txt

									[oracle@oracle235 ~]$ sqlplus lottu/li0924

									SQL*Plus: Release 11.2.0.4.0 Production on Mon Aug 13 22:58:34 2018

									Copyright (c) 1982, 2013, Oracle. All rights reserved.

									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

									SQL> create table tbl_load_01 (id number,name varchar2(10),accountid number);

									Table created.

3.2 创建控制文件lottu.ctl

				?

									load data

									characterset utf8

									    infile '/home/oracle/lottu.txt'

									    truncate into table tbl_load_01

									    fields terminated by ','

									    trailing nullcols

									 optionally enclosed by ' ' TRAILING NULLCOLS

									(

									 id ,

									 name,

									 accountid

									)

3.3 执行sqlldr

				?

									[oracle@oracle235 ~]$ sqlldr 'lottu/"li0924"' control=/home/oracle/lottu.ctl log=/home/oracle/lottu.log bad=/home/oracle/lottu.bad

									SQL*Loader: Release 11.2.0.4.0 - Production on Mon Aug 13 23:10:12 2018

									Copyright (c) 1982, 2011, Oracle and/or its affiliates. All rights reserved.

									Commit point reached - logical record count 64

									Commit point reached - logical record count 128

									Commit point reached - logical record count 192

									Commit point reached - logical record count 256

									Commit point reached - logical record count 320

									Commit point reached - logical record count 384

									Commit point reached - logical record count 448

									Commit point reached - logical record count 512

									Commit point reached - logical record count 576

									Commit point reached - logical record count 640

									Commit point reached - logical record count 704

									Commit point reached - logical record count 768

									Commit point reached - logical record count 832

									Commit point reached - logical record count 896

									Commit point reached - logical record count 960

									Commit point reached - logical record count 1000

四.Oracle卸载数据-sqludr

　　sqludr是将Oracle数据表导出到文本中；是牛人楼方鑫开发的。并非Oracle自带工具；需要下载安装才能使用。

4.1 sqludr安装

				?

									[oracle@oracle235 ~]$ unzip sqluldr2linux64.zip 

									Archive: sqluldr2linux64.zip

									 inflating: sqluldr2linux64.bin   

									[oracle@oracle235 ~]$ mv sqluldr2linux64.bin $ORACLE_HOME/bin/sqludr

4.2 查看sqludr帮助

				?

									[oracle@oracle235 ~]$ sqludr -?

									SQL*UnLoader: Fast Oracle Text Unloader (GZIP, Parallel), Release 4.0.1

									(@) Copyright Lou Fangxin (AnySQL.net) 2004 - 2010, all rights reserved.

									License: Free for non-commercial useage, else 100 USD per server.

									Usage: SQLULDR2 keyword=value [,keyword=value,...]

									Valid Keywords:

									  user  = username/password@tnsname

									  sql   = SQL file name

									  query  = select statement

									  field  = separator string between fields

									  record = separator string between records

									  rows  = print progress for every given rows (default, 1000000) 

									  file  = output file name(default: uldrdata.txt)

									  log   = log file name, prefix with + to append mode

									  fast  = auto tuning the session level parameters(YES)

									  text  = output type (MYSQL, CSV, MYSQLINS, ORACLEINS, FORM, SEARCH).

									  charset = character set name of the target database.

									  ncharset= national character set name of the target database.

									  parfile = read command option from parameter file 

									 for field and record, you can use '0x' to specify hex character code,

									 \r=0x0d \n=0x0a |=0x7c ,=0x2c, \t=0x09, :=0x3a, #=0x23, "=0x22 '=0x27

4.3 执行sqludr

				?

									[oracle@oracle235 ~]$ sqludr lottu/li0924 query="tbl_load_01" file=lottu01.txt field=","

									      0 rows exported at 2018-08-13 23:47:55, size 0 MB.

									    1000 rows exported at 2018-08-13 23:47:55, size 0 MB.

									     output file lottu01.txt closed at 1000 rows, size 0 MB.