char data type used in c language while varchar used in mysql query
Char stores fixed-length character strings, meaning it always occupies a set amount of space, no matter what. Varchar, on the other hand, is more flexible. It stores variable-length character strings, only using as much space as needed. So, in a nutshell, Char is like having a fixed parking spot, while Varchar is more chill, taking up only the space it requires.
In SQL, both CHAR and VARCHAR are used to store character data. However, there are some key differences between them.
The CHAR datatype is used to store fixed-length character strings. When you define a CHAR column, you must specify the maximum number of characters it can hold. For example, if you define a CHAR(10) column, it will always occupy 10 characters of storage, regardless of the actual length of the data stored in it. If you store a shorter string, it will be padded with spaces to fill the remaining space.
On the other hand, the VARCHAR datatype is used to store variable-length character strings. When you define a VARCHAR column, you also specify the maximum number of characters it can hold. However, unlike CHAR, a VARCHAR column only occupies the actual length of the data stored in it, plus a small overhead. This means that if you store a shorter string, it will not be padded with spaces.
The choice between CHAR and VARCHAR depends on the nature of the data you are storing. If the length of the data is always fixed, or if you need to compare strings based on their exact length, CHAR is a better choice. On the other hand, if the length of the data varies and you want to save storage space, VARCHAR is more suitable.