What is the difference between CHAR and VARCHAR data types in SQL?
a) CHAR is of fixed length, while VARCHAR is of variable length
b) CHAR can store numbers, while VARCHAR cannot
c) CHAR is case-insensitive, while VARCHAR is case-sensitive
d) CHAR is faster for numeric values, while VARCHAR is faster for text
Answer:
a) CHAR is of fixed length, while VARCHAR is of variable length
Explanation:
CHAR is a fixed-length data type, meaning that if a string is shorter than the defined length, it will be padded with spaces to meet the specified length. VARCHAR, on the other hand, is a variable-length data type, meaning that it only uses as much storage as needed for the string.
For example, a CHAR(10) column will always store 10 characters, even if the actual data is shorter, while a VARCHAR(10) column will store exactly the number of characters in the string, up to a maximum of 10.
VARCHAR is generally more space-efficient for storing variable-length data, while CHAR can be faster when storing fixed-length data.