What does "size" in int(size) of MySQL mean?
SHOW PROCESSLIST or show status where `variable_name` = 'Threads_connected';
昨晚有实现一个小功能，就是在MS SQL Server中，检查字符串是否包含有大小写字母。通常应用在字符串的复杂度。
Friday, August 24th, 2007 at 21:40 +0000 (UTC) by Alexander Kirk
DECLARE @s NVARCHAR(40) = N'SDFfgGRYJhhTYUJ' IF LOWER(@s) COLLATE Latin1_General_CS_AS <> @s AND UPPER(@s) COLLATE Latin1_General_CS_AS <> @s PRINT 'T' ELSE PRINT 'F'
I was always wondering what the size of numeric columns in MySQL was. Forgive me if this is obvious to someone else. But for me the MySQL manual lacks a great deal in this field.
TL;DR: It's about the display width. You only see it when you use ZEROFILL.
Usually you see something like
CREATE TABLE statements,
but you can also change it to
So what does this size mean? Can you store higher values in
int(11) than in an
Let's see what the MySQL manual says:
INT[(M)] [UNSIGNED] [ZEROFILL]
A normal-size integer. The signed range is -2147483648 to 2147483647. The unsigned range is 0 to 4294967295.
No word about the
M. The entry about
BOOL suggests that the size is
not there for fun as it is a synonym for
TINYINT(1) (with the specific
size of 1).
TINYINT[(M)] [UNSIGNED] [ZEROFILL]
A very small integer. The signed range is -128 to 127. The unsigned range is 0 to 255.
These types are synonyms for TINYINT(1). A value of zero is considered false. Non-zero values are considered true: […]