SQLite Data Types

SQLite data types are used to specify type of data of any object. Each column, variable and expression has related data type in SQLite. These data types are used while creating table. SQLite uses a more general dynamic type system. In SQLite, the datatype of a value is associated with the value itself, not with its container.

Types of SQLite data types

SQLite Storage Classes

The stored values in a SQLite database has one of the following storage classes:

Storage Class Description
NULL It specifies that the value is a null value.
INTEGER It specifies the value is a signed integer, stored in 1, 2, 3, 4, 6, or 8 bytes depending on the magnitude of the value.
REAL It specifies the value is a floating point value, stored as an 8-byte IEEE floating point number.
text It specifies the value is a text string, stored using the database encoding (utf-8, utf-16be or utf-16le)
BLOB It specifies the value is a blob of data, stored exactly as it was input.
Note
Note: SQLite storage class is slightly more general than a data type. For example: The INTEGER storage class includes 6 different integer data types of different lengths.

SQLite Afinity Types

SQLite supports type affinity for columns. Any column can still store any type of data but the preferred storage class for a column is called its affinity.

There are following type affinity used to assign in SQLite3 database.

Affinity Description
TEXT This column is used to store all data using storage classes NULL, TEXT or BLOB.
NUMERIC This column may contain values using all five storage classes.
INTEGER It behaves the same as a column with numeric affinity with an exception in a cast expression.
REAL It behaves like a column with numeric affinity except that it forces integer values into floating point representation
NONE A column with affinity NONE does not prefer one storage class over another and don't persuade data from one storage class into another.

SQLite Affinity and Type Names

Following is a list of various data types names which can be used while creating SQLite tables.

Data Types Corresponding Affinity
INT INTEGER TINYINT SMALLINT MEDIUMINT BIGINT UNSIGNED BIG INT INT2 INT8 INTEGER
CHARACTER(20) VARCHAR(255) VARYING CHARACTER(255) NCHAR(55) NATIVE CHARACTER(70) NVARCHAR(100) TEXT CLOB TEXT
BLOB no datatype specified NONE
REAL DOUBLE DOUBLE PRECISION FLOAT REAL
NUMERIC DECIMAL(10,5) BOOLEAN DATE DATETIME NUMERIC

Date and Time Data Type

In SQLite, there is no separate class to store dates and times. But you can store date and times as TEXT, REAL or INTEGER values.

Storage Class Date Format
TEXT It specifies a date in a format like "yyyy-mm-dd hh:mm:ss.sss".
REAL It specifies the number of days since noon in Greenwich on November 24, 4714 B.C.
INTEGER It specifies the number of seconds since 1970-01-01 00:00:00 utc.

Boolean Data Type

In SQLite, there is not a separate Boolean storage class. Instead, Boolean values are stored as integers 0 (false) and 1 (true).

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