Limit number of characters of a text field

Question

I want a field "name" be long at most 20 characters...is it possible in sqllite?

Answer 1

Yes with CHECK CONSTRAINTS. Here is an example enforcing TEXT datatype with a length of less than or equal to 20 characters.

CREATE TABLE IF NOT EXISTS "test"
(
    "id" INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,
    "name" TEXT NOT NULL
    CHECK(
        typeof("name") = "text" AND
        length("name") <= 20
    )
);

INSERT INTO "test" ("name") VALUES ("longer than twenty characters");

Result:

Error: CHECK constraint failed: test

Probably too late to help the OP but maybe someone else will find this useful.

Answer 2

No. Per Datatypes In SQLite Version 3,

Note that numeric arguments in parentheses that following the type name (ex: "VARCHAR(255)") are ignored by SQLite - SQLite does not impose any length restrictions (other than the large global SQLITE_MAX_LENGTH limit) on the length of strings, BLOBs or numeric values.