最近由于遇到oracle控制文件的使用，虽然不是很复杂，但是从来没有用过，专门花点时间看看。点击 这里 查看详细
1，概述：
Sql Loader: 一个批量工具，将文件数据导入到数据库。可以导入一个表或者多个表，甚至可以在导入时修改数据。
2，使用
a,你电脑需要装Oracle,不然你是找不到Sqlldr 这个命令的。
在控制输入台输入 sqlldr：
会列出相关的参数介绍。
> sqlldr . . . Usage: SQLLDR keyword=value [,keyword=value,...] Valid Keywords: userid -- ORACLE username/password control -- control file name log -- log file name bad -- bad file name data -- data file name discard -- discard file name discardmax -- number of discards to allow (Default all) skip -- number of logical records to skip (Default 0) load -- number of logical records to load (Default all) errors -- number of errors to allow (Default 50) rows -- number of rows in conventional path bind array or between direct path data saves (Default: Conventional path 64, Direct path all) bindsize -- size of conventional path bind array in bytes (Default 256000) silent -- suppress messages during run (header,feedback,errors,discards, partitions) direct -- use direct path (Default FALSE) parfile -- parameter file: name of file that contains parameter specifications parallel -- do parallel load (Default FALSE) file -- file to allocate extents from skip_unusable_indexes -- disallow/allow unusable indexes or index partitions (Default FALSE) skip_index_maintenance -- do not maintain indexes, mark affected indexes as unusable (Default FALSE) commit_discontinued -- commit loaded rows when load is discontinued (Default FALSE) readsize -- size of read buffer (Default 1048576) external_table -- use external table for load; NOT_USED, GENERATE_ONLY, EXECUTE (Default NOT_USED) columnarrayrows -- number of rows for direct path column array (Default 5000) streamsize -- size of direct path stream buffer in bytes (Default 256000) multithreading -- use multithreading in direct path resumable -- enable or disable resumable for current session (Default FALSE) resumable_name -- text string to help identify resumable statement resumable_timeout -- wait time (in seconds) for RESUMABLE (Default 7200) date_cache -- size (in entries) of date conversion cache (Default 1000) PLEASE NOTE: Command-line parameters may be specified either by position or by keywords. An example of the former case is 'sqlldr scott/tiger foo'; an example of the latter is 'sqlldr control=foo userid=scott/tiger'.One may specify parameters by position before but not after parameters specified by keywords.For example, 'sqlldr scott/tiger control=foo logfile=log' is allowed, but 'sqlldr scott/tiger control=foo log' is not, even though the position of the parameter 'log' is correct.
b, sqlldr 将文本文件的导入到数据库
这里看个简单例子。看看sqlldr到底怎么工作的。
1,准备数据文件，例如input.txt.这个文件将导入到数据库中。
首先查看我们数据库的表格式。
create table student( SNAME VARCHAR(20), SAGE INTEGER, SEMAIL VARCHAR(20), SPHONE VARCHAR(20), SADDRESS VARCHAR(20) )
input.txt 文件
12,12,abc@gmail.com,12,address 13,13,abc@gmail.com,13,address 14,14,abc@gmail.com,14,address 15,15,abc@gmail.com,15,address 16,16,abc@gmail.com,16,address 17,17,abc@gmail.com,17,address 18,18,abc@gmail.com,18,address 19,19,abc@gmail.com,19,address
2，控制文件input.ctl
load data infile 'input.txt' append into table student --这里用的Append. fields terminated by "," --这里表示逗号分割。 (SNAME,SAGE,SEMAIL,SPHONE,SADDRESS)
这里用的Append, 追加数据，还有几个其他的参数：
a，insert，为缺省方式，在数据装载开始时要求表为空
b，append，在表中追加新记录
c ，replace，删除旧记录，替换成新装载的记录
d，truncate，同上
3，sqlldr 调用控制文件
sqlldr username/password@Database control =input.ctl //input.ctl 为控制文件
在这里需要提下，这里是会生成日志文件，默认为文件名文件名+.log. 当前为 input.log
如果执行失败了，会生成bad file. 如果在当前执行中错误，会生成input.bad file。
下面指定Log 和bad 文件，当然可以加上路径
sqlldr userid=username/password@database control=input.ctl log=input.log bad=input.bad SILENT=(HEADER, FEEDBACK)
SILENT=(HEADER, FEEDBACK) 控制端不显示信息，例如下面的信息将不再控制端显示。只在日志文件中
Record 4: Rejected - Error on table EMP ORA-00001: unique constraint <name> violated
当然是可以显示指定的。
load data infile input.txt badfile t.bad discardfile t.dsc append into table student fields terminated by "," (SNAME,SAGE,SEMAIL,SPHONE,SADDRESS)
看看日志文件：input.log
SQL*Loader: Release 10.2.0.1.0 - Production on Tue May 20 17:36:52 2014 Copyright (c) 1982, 2005, Oracle. All rights reserved. Control File: input1.ctl Data File: input1.ctl Bad File: input1.bad Discard File: none specified (Allow all discards) Number to load: ALL Number to skip: 0 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: APPEND Column Name Position Len Term Encl Datatype ------------------------------ ---------- ----- ---- ---- --------------------- SNAME FIRST * , CHARACTER SAGE NEXT * , CHARACTER SEMAIL NEXT * , CHARACTER SPHONE NEXT * , CHARACTER SADDRESS NEXT * , CHARACTER Table STUDENT: 1 Row successfully loaded. 0 Rows 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: 82560 bytes(64 rows) Read buffer bytes: 1048576 Total logical records skipped: 0 Total logical records read: 1 Total logical records rejected: 0 Total logical records discarded: 0 Run began on Tue May 20 17:36:52 2014 Run ended on Tue May 20 17:36:52 2014 Elapsed time was: 00:00:00.05 CPU time was: 00:00:00.04
4，查看数据库
到此一个简单的例子完成，从一个文本文件导入到数据库。
文件可以为不同格式文件，.dat,.csv都可以的。
C,sqlldr直接在控制文件中导入数据。
load data infile * append into table student fields terminated by "," (SNAME,SAGE,SEMAIL,SPHONE,SADDRESS) begindata 20,20,abc@gmail.com,20,address --这里是数据
D,当文件数据是以绝对位置分开的，我们可以直接截取。当然，截取的开始与结束必须小心了。
load data infile t.dat append into table student (SNAME position(01:20), SAGE position(21:23) , SEMAIL position(41:60), SPHONE position(61:80), SADDRESS position(81:100) )
t.dat 文件
Jack 12 abc@gmail.com 134998879 Singapore Jack2 12 abc@gmail.com 134998879 Singapore Jack3 12 abc@gmail.com 134998879 Singapore Jack4 12 abc@gmail.com 134998879 Singapore Jack5 12 abc@gmail.com 134998879 Singapore Jack6 12 abc@gmail.com 134998879 Singapore Jack7 12 abc@gmail.com 134998879 Singapore
还数据在Load to database 的时候，load的数据是可以改变的。
LOAD DATA INFILE * INTO TABLE modified_data ( rec_no "my_db_sequence.nextval", region CONSTANT '31', time_loaded "to_char(SYSDATE, 'HH24:MI')", data1 POSITION(1:5) ":data1/100", data2 POSITION(6:15) "upper(:data2)", data3 POSITION(16:22)"to_date(:data3, 'YYMMDD')" ) BEGINDATA 11111AAAAAAAAAA991201 22222BBBBBBBBBB990112
可以将多个文件导入到同一个表或者多个表中
load data infile t1.dat infile t2.dat infile t3.dat append into table student (SNAME position(01:20), SAGE position(21:23) , SEMAIL position(41:60), SPHONE position(61:80), SADDRESS position(81:100) )
这里有很多命令的解释
简单实现几个例子，稍后有时间添加多点理论知识，再边学习边完善了。