I'm reading the output of the exec sp_columns command and there are 2 columns I can't understand PRECISION and LENGTH

I just created the following table

If I'm not mistaken, the quantity column is a numeric INTENGER data type, that is, this column can store a number between -2,147,483,648 and 2,147,483,647

This information is correct right?

but if i execute

exec sp_columns Books;

Precision: I think it is the number of characters that the column allows, that is, a maximum of 10 characters between -2.1m and 2.1m

but I can't figure out why the LENGTH column says 4.

CREATE TABLE Books
(
    title VARCHAR(10), -- Maximum length up to 10 characters example 'ABCDFGHIJK'
    author VARCHAR(10),-- Maximum length up to 10 characters example 'ABCDFGHIJK'
    quantity INTEGER   -- ?
);
exec sp_columns Books;

INSERT INTO Prueba.dbo.Books
    (title,author,quantity)
VALUES
    ('Example A', 'A', 1),
    ('Example B', 'B', 12),
    ('Example C', 'C', 123),
    ('Example D', 'D', 123467890),
    ('Example E', 'E', 1234678901);

CodePudding user response：

What LENGTH represents it defined in the documentation:

Column name	Data type	Dscription
LENGTH	int	Transfer size of the data.1

¹ For more information, see the Microsoft ODBC documentation^*.

^{*The documentation does not contain a link to which Microsoft ODBC documentation they mean specifically, so the omission is not mine}

An int is 4 bytes in size, and hence the column has a LENGTH of 4 defined in sys.sp_columns.