Introduction

Like most data types, strings can be compared for equality or inequality or relative ordering. However, strings have some additional properties to consider:

This chapter discusses several useful string operations you can perform, including how to account for whether or not strings are case sensitive.

The following table, metal, is used in several sections of this chapter:

mysql> SELECT * FROM metal; +----------+ | name | +----------+ | copper | | gold | | iron | | lead | | mercury | | platinum | | silver | | tin | +----------+

The table is very simple, containing only a single string column:

CREATE TABLE metal ( name VARCHAR(20) );

You can create the table using the metal.sql script in the tables directory of the recipes distribution.

4.1.1 Types of Strings

MySQL can operate on regular strings or binary strings. "Binary" in this context has little to do with the presence of non-ASCII values, so it's useful right at the outset to make a distinction:

A binary column type is one that contains binary strings. Some of MySQL's column types are binary (case sensitive) and others are not, as illustrated here:

Column type

Binary/case sensitive

CHAR, VARCHAR

No

CHAR BINARY, VARCHAR BINARY

Yes

TEXT

No

BLOB

Yes

ENUM, SET

No

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