Specifying Input Column Order

10.12.1 Problem

The columns in your datafile aren't in the same order as the columns in the table into which you're loading the file.

10.12.2 Solution

Tell LOAD DATA how to match up the table and the file by indicating which table columns correspond to the datafile columns.

10.12.3 Discussion

LOAD DATA assumes the columns in the datafile have the same order as the columns in the table. If that's not true, you can specify a list to indicate which table columns the datafile columns should be loaded into. Suppose your table has columns a, b, and c, but successive columns in the datafile correspond to columns b, c, and a. You can load the file like this:

mysql> LOAD DATA LOCAL INFILE 'mytbl.txt' INTO TABLE mytbl (b, c, a);

The equivalent mysqlimport statement uses the --columns option to specify the column list:

% mysqlimport --local --columns=b,c,a cookbook mytbl.txt

The --columns option for mysqlimport was introduced in MySQL 3.23.17. If you have an older version, you must either use LOAD DATA directly or preprocess your datafile to rearrange the file's columns into the order in which they occur in the table. (See Recipe 10.20 for a utility that can do this.)

Using the mysql Client Program

Writing MySQL-Based Programs

Record Selection Techniques

Working with Strings

Working with Dates and Times

Sorting Query Results

Generating Summaries

Modifying Tables with ALTER TABLE

Obtaining and Using Metadata

Importing and Exporting Data

Generating and Using Sequences

Using Multiple Tables

Statistical Techniques

Handling Duplicates

Performing Transactions

Introduction to MySQL on the Web

Incorporating Query Resultsinto Web Pages

Processing Web Input with MySQL

Using MySQL-Based Web Session Management

Appendix A. Obtaining MySQL Software

Appendix B. JSP and Tomcat Primer

Appendix C. References



MySQL Cookbook
MySQL Cookbook
ISBN: 059652708X
EAN: 2147483647
Year: 2005
Pages: 412
Authors: Paul DuBois

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