SQLite - working with text (varchar)?

Question

SQL

You need to update via update, which will add one letter to the line. My attempt:
create table Test(
Num varchar(6)
);
UPDATE Test
SET Num=Num+"x";
was not crowned with success, tk. Arithmetic operations cannot be applied to varchar fields.
Concate from SQL cannot be used either, as well as some other things from SQL.
In general, I honestly tried to google the answer for a long time, but it doesn’t work.
Can you help?

Answer 1

To concatenate (join) text strings in the SQLite language, it is not a plus, but the “||” operator, according to the operator documentation .

Answer 2

SQLite data types : INTEGER, REAL, TEXT, BLOB or NULL. Use text.