Working with Strings - MySQL - page 139

CHAPTER 5
Working with Strings
5.0. 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 of the
recipes distribution.