How to create ENUM type in SQLite?

Question

SQLite way is to use a CHECK constraint.

Some examples:

CREATE TABLE prices (
 id         INTEGER                                PRIMARY KEY,
 pName      TEXT CHECK( LENGTH(pName) <= 100 )     NOT NULL DEFAULT '',
 pType      TEXT CHECK( pType IN ('M','R','H') )   NOT NULL DEFAULT 'M',
 pField     TEXT CHECK( LENGTH(pField) <= 50 )     NULL DEFAULT NULL,
 pFieldExt  TEXT CHECK( LENGTH(pFieldExt) <= 50 )  NULL DEFAULT NULL,
 cmp_id     INTEGER                                NOT NULL DEFAULT '0'
)

This will limit the pType column to just the values M, R, and H, just like enum("M", "R", "H") would do in some other SQL engines.

There is no enum type in SQLite, only the following:

• NULL
• INTEGER
• REAL
• TEXT
• BLOB

Source: http://www.sqlite.org/datatype3.html

I'm afraid a small, custom enum table will be required in your case.

To expand on MPelletier’s answer, you can create the tables like so:

CREATE TABLE Price (
  PriceId INTEGER       PRIMARY KEY AUTOINCREMENT NOT NULL,
  Name    VARCHAR(100)  NOT NULL,
  Type    CHAR(1)       NOT NULL DEFAULT ('M') REFERENCES PriceType(Type)
);

CREATE TABLE PriceType (
  Type    CHAR(1)       PRIMARY KEY NOT NULL,
  Seq     INTEGER
);
INSERT INTO PriceType(Type, Seq) VALUES ('M',1);
INSERT INTO PriceType(Type, Seq) VALUES ('R',2);
INSERT INTO PriceType(Type, Seq) VALUES ('H',3);

Now the enumeration values are available directly in the Price table as they would be using an ENUM: you don’t need to join to the PriceType table to get the Type values, you only need to use it if you want to determine the sequence of the ENUMs.

Foreign key constraints were introduced in SQLite version 3.6.19.