Preserving Trailing Spaces in String Columns

4.3.1 Problem

MySQL strips trailing spaces from strings, but you want to preserve them.

4.3.2 Solution

Use a different column type.

4.3.3 Discussion

If you store a string that contains trailing spaces into the database, you may find that they're gone when you retrieve the value. This is the normal MySQL behavior for CHAR and VARCHAR columns; the server returns values from both types of columns without trailing spaces. If you want to preserve trailing spaces, use one of the TEXT or BLOB column types. (The TEXT types are not case sensitive, the BLOB types are.) The following example illustrates the difference in behavior for VARCHAR and TEXT columns:

mysql> CREATE TABLE t (c VARCHAR(255));
mysql> INSERT INTO t (c) VALUES('abc ');
mysql> SELECT c, LENGTH(c) FROM t;
+------+-----------+
| c | LENGTH(c) |
+------+-----------+
| abc | 3 |
+------+-----------+
mysql> DROP TABLE t;
mysql> CREATE TABLE t (c TEXT);
mysql> INSERT INTO t (c) VALUES('abc ');
mysql> SELECT c, LENGTH(c) FROM t;
+------------+-----------+
| c | LENGTH(c) |
+------------+-----------+
| abc | 10 |
+------------+-----------+

There are plans to introduce a VARCHAR type that retains trailing spaces in a future version of MySQL.

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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