SQLite | SQLite Functions | Returning the Data Type of a Stored Value (typeof Function)
The typeof function identifies the data type of a value stored in a table. This article explains how to use the function.
Using the typeof Function
The typeof function identifies the data type of a value. Its syntax is as follows.
typeof(value)
In SQLite, the declared data type of a table column and the data type of the value actually stored in it must be considered separately. For more information, see Data Types.
The typeof function returns a string that identifies the value’s data type. The result is one of integer, real, text, blob, or null. When a column name is supplied, the function returns the data type of the value stored in that column.
–
Let’s try an example. First, create the following table.
create table test (id integer, data none);
sqlite> create table test (id integer, data none);
sqlite>
Add the following data with INSERT statements.
insert into test values (1, 3);
insert into test values (2, 15.24);
insert into test values (3, 'Peach');
insert into test values (4, NULL);
insert into test values (5, zeroblob(2));
sqlite> insert into test values (1, 3);
sqlite> insert into test values (2, 15.24);
sqlite> insert into test values (3, 'Peach');
sqlite> insert into test values (4, NULL);
sqlite> insert into test values (5, zeroblob(2));
sqlite>
Use the typeof function to identify the data types of the values stored in the data column.
select data, typeof(data) from test;
sqlite> .mode column
sqlite> .header on
sqlite>
sqlite> select data, typeof(data) from test;
data typeof(data)
---------- ------------
3 integer
15.24 real
Peach text
null
blob
sqlite>
The data type of each value stored in the column is displayed.