MySQL How to choose the right data type 1:char and varchar

Char is similar to a varchar type and is used to store strings, but they are "saved" and "retrieved" in different ways. Char is a "fixed-length" string, and varchar is a character type of "variable length."

The following table shows the results of saving various string values to char (4) and varchar (4) columns, explaining the difference between char and varchar.

Comparison of Char and varchar

Value	CHAR (4)	Storage requirements	VARCHAR (4)	Storage requirements
‘‘	‘ ‘	4 bytes	‘‘	1 bytes
' AB '	' AB '	4 bytes	' AB '	3 bytes
' ABCD '	' ABCD '	4 bytes	' ABCD '	5 bytes
' Abcdefgh '	' ABCD '	4 bytes	' ABCD '

　　

How MySQL chooses the appropriate data type 1:char and varchar