hi, can u tell how many columns a table can have?

Answer 1

Yes. There are different ways, depending on which version you use.
In PostgreSQL, you'd enter "\d" (or "\l" in some cases) into the prompt, and you'd be provided a list of tables.
In SQLite3, you'd enter ".tables" to get the same thing, for example.

You can even find out the total number of rows in each table.
In SQLite3, using Python, that code might look something like this:

database = sqlite3.connect('example.db')
db = database.cursor()
x = db.execute('SELECT * FROM example_table').fetchall()
print('The table has ' + str(len(x)) + ' rows.')

What is returned upon assigning x the database query, is a list of "tuples", meaning a list of rows containing the data you queried from the database. In the print statement, I have "len(x)", which would return the total quantity of rows.

Answer 2

you can create more 250 - 1000

Answer 3

Even more in some situation.