MySQL Cookbook

Specifying Input Column Order

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.

Solution

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

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.)