I am fairly new to SQLITE and I noticed that there are only a 4 datatypes but I see examples online where people are putting in their own datatypes. I don't really understand this and was wondering if someone could explain that to me. For example I see a column that will hold a date and the datatype that was given was timestamp which does not exist. What does it default to? Does it default to a text when you make your own?
SQLite only has four primitive data types: INTEGER, REAL, TEXT, and BLOB.
(10) Does SQLite support a BLOB type? SQLite allows you to store BLOB data in any column, even columns that are declared to hold some other type. BLOBs can even be used as PRIMARY KEYs.
SQLite stores JSON as ordinary text. Backwards compatibility constraints mean that SQLite is only able to store values that are NULL, integers, floating-point numbers, text, and BLOBs. It is not possible to add a sixth "JSON" type. SQLite does not (currently) support a binary encoding of JSON.
The SQLite docs explains why this is so slow: Transaction speed is limited by disk drive speed because (by default) SQLite actually waits until the data really is safely stored on the disk surface before the transaction is complete.
sqlite3
uses a dynamic type system. There are only five storage classes:
NULL, integer, real, text and blob. (Source: Datatypes In SQLite Version 3.)
And, to quote that page:
Any column in an SQLite version 3 database, except an INTEGER PRIMARY KEY column, may be used to store a value of any storage class.
Apart from the integer primary key
exception, SQLite doesn't enforce types at all. Which means that the type name you put in your create table
is purely informative.
create table mytab (a apples, b bananas);
is a valid create table
statement. You can insert timestamps, text, blobs into both columns (not saying that you should, but you can).
Look at the linked reference documentation for the type system for more information.
sqlite> create table mytab (a apples, b bananas);
sqlite> insert into mytab values (CURRENT_TIME, NULL);
sqlite> insert into mytab values ('hello', 3.14159);
sqlite> select * from mytab;
14:59:18|
hello|3.14159
To answer your question directly: there is no default. A storage type is associated with each value stored in the database, not to columns of a table.
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With