Table Column Types for Look Up Values

Describes 2 types of table columns to store look up values: ENUM and SET.

There are 2 types of table columns to store look up values: ENUM, SET.

"ENUM" - A look up value from a predefined list. ENUM actually stores the index of the value as an integer.

"SET" - A combination of look up values from a predefined list. SET actually uses 64 bits and their position to represent each look up value. So a SET can support only up to 64 values.

Examples of look up value column types, EnumSetColumns.sql:

-- EnumSetColumns.sql
-- Copyright (c) 2005 All Rights Reserved.
   Line VARCHAR(2),
   E ENUM('Mercury', 'Venus', 'Earth', 'Mars'),
   S SET('a','b','c','d')

SELECT Line, E+0, S+0 FROM EnumSet;


Running EnumSetColumns.sql on MySQL 8.0 server gives you:

herong> %mysql%\bin\mysql --user=root --password=TopSecret test \
   < EnumSetColumns.sql

Line    E       S
1       Earth   c
1       Earth   a,c

Line    E+0     S+0
1       3       4
1       3       5

Note that ENUM and SET columns actually store integers to represent look up values.

Table of Contents

 About This Book

 Introduction of SQL

 MySQL Introduction and Installation

 Introduction of MySQL Programs

 PHP Programs and MySQL Server

 Perl Programs and MySQL Servers

 Java Programs and MySQL Servers

 Datatypes and Data Literals

 Operations and Expressions

 Character Strings and Bit Strings

 Commonly Used Functions

Table Column Types for Different Types of Values

 Table Column Types for Character Strings

 Table Column Types for Byte Strings

 Table Column Types for Bit Strings

 Table Column Types for Exact Numbers

 Table Column Types for Approximate Numbers

 Table Column Types for Date and Time Values

 Table Column Types for LOB (Large OBject)

Table Column Types for Look Up Values

 Table Column Types for JSON Documents

 Table Column Types for Spatial Geometry Data

 Using DDL to Create Tables and Indexes

 Using DML to Insert, Update and Delete Records

 Using SELECT to Query Database

 Window Functions for Statistical Analysis

 Use Index for Better Performance

 Transaction Management and Isolation Levels

 Locks Used in MySQL

 Defining and Calling Stored Procedures

 Variables, Loops and Cursors Used in Stored Procedures

 System, User-Defined and Stored Procedure Variables

 MySQL Server Administration

 Storage Engines in MySQL Server

 InnoDB Storage Engine - Primary and Secondary Indexes

 Performance Tuning and Optimization

 Bulk Changes on Large Tables

 MySQL Server on macOS

 Installing MySQL Server on Linux

 Connection, Performance and Second Instance on Linux

 Archived Tutorials


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