What is SQL*Loader and what is it used for?[edit]
SQL*Loader is a bulk loader utility used for moving data from external files into the Oracle database. Its syntax is similar to that of the DB2 load utility, but comes with more options. SQL*Loader supports various load formats, selective loading, and multi-table loads.
SQL*Loader (sqlldr) is the utility to use for high performance data loads. The data can be loaded from any text file and inserted into the database.
How does one use the SQL*Loader utility?[edit]
One can load data into an Oracle database by using the sqlldr (sqlload on some platforms) utility. Invoke the utility without arguments to get a list of available parameters. Look at the following example:
sqlldr username@server/password control=loader.ctl sqlldr username/password@server control=loader.ctl
This sample control file (loader.ctl) will load an external data file containing delimited data:
load data infile 'c:\data\mydata.csv' into table emp fields terminated by "," optionally enclosed by '"' ( empno, empname, sal, deptno )
The mydata.csv file may look like this:
10001,"Scott Tiger", 1000, 40 10002,"Frank Naude", 500, 20
Optionally, you can work with tabulation delimited files by using one of the following syntaxes:
fields terminated by "\t" fields terminated by X'09'
Additionally, if your file was in Unicode, you could make the following addition.
load data CHARACTERSET UTF16 infile 'c:\data\mydata.csv' into table emp fields terminated by "," optionally enclosed by '"' ( empno, empname, sal, deptno )
Another Sample control file with in-line data formatted as fix length records. The trick is to specify "*" as the name of the data file, and use BEGINDATA to start the data section in the control file:
load data
infile *
replace
into table departments
( dept position (02:05) char(4),
deptname position (08:27) char(20)
)
begindata
COSC COMPUTER SCIENCE
ENGL ENGLISH LITERATURE
MATH MATHEMATICS
POLY POLITICAL SCIENCE
这样我们就可以把数据量特别大的csv导入到oracle中了。