MySQL Cookbook, 4th Edition

Chapter 7. Working with Strings

7.0 Introduction

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

• A string can be binary or nonbinary. Binary strings are used for raw data such as images, music files, or encrypted values. Nonbinary strings are used for character data such as text and are associated with a character set and collation (sort order).

• A character set determines which characters are legal in a string. You can choose collations according to whether you need comparisons to be case sensitive or case insensitive, or to use the rules of a particular language.

• Data types for binary strings are BINARY, VARBINARY, and BLOB. Data types for nonbinary strings are CHAR, VARCHAR, and TEXT, each of which permits CHARACTER SET and COLLATE attributes.

• You can convert a binary string to a nonbinary string and vice versa, or convert a nonbinary string from one character set or collation to another.

• You can use a string in its entirety or extract substrings from it. Strings can be combined with other strings.

• You can apply pattern-matching operations to strings.

• Full-text searching is available for efficient queries on large collections of text.

This chapter discusses how to use those properties so that you can store, retrieve, and manipulate strings according to any requirements your applications have.

Scripts to create the tables used in this chapter are located in the tables directory ...