What is VARCHAR in SQL with example?
VARCHAR is a variable length string data type, so it holds only the characters you assign to it. VARCHAR takes up 1 byte per character, + 2 bytes to hold length information. For example, if you set a VARCHAR(100) data type = ‘Jen’, then it would take up 3 bytes (for J, E, and N) plus 2 bytes, or 5 bytes in all.
What does VARCHAR 20 mean?
The data type of varchar is Variable-length with non-Unicode character data. The storage size is the actual length of data entered + 2 bytes. • For varchar (20): The max storage size is: 20*1 byte +2 bytes=22 bytes; •
What’s the difference between CHAR and VARCHAR in SQL?
CHAR is fixed length and VARCHAR is variable length. CHAR always uses the same amount of storage space per entry, while VARCHAR only uses the amount necessary to store the actual text. The char is a fixed-length character data type, the varchar is a variable-length character data type.
What does VARCHAR 10 mean?
To give you an example, CHAR(10) is a fixed-length non-Unicode string of length 10, while VARCHAR(10) is a variable-length non-Unicode string with a maximum length of 10. This means the actual length will depend upon the data.
Why varchar is used in SQL?
As the name suggests, varchar means character data that is varying. … SQL varchar usually holds 1 byte per character and 2 more bytes for the length information. It is recommended to use varchar as the data type when columns have variable length and the actual data is way less than the given capacity.
What is difference between varchar and VARCHAR2?
VARCHAR2 is the same as VARCHAR in the oracle database. The main difference is that VARCHAR is ANSI Standard and VARCHAR2 is Oracle standard. The VarChar2 data type is used to store the character values. It is a variable-length data type i.e we can change the size of the character variable at execution time.
What does VARCHAR 255 mean?
The length can be specified as a value from 0 to 65,535. The effective maximum length of a VARCHAR is subject to the maximum row size (65,535 bytes, which is shared among all columns) and the character set used. … VARCHAR(255) stores 255 characters, which may be more than 255 bytes.
Why is VARCHAR 255?
255 is used because it’s the largest number of characters that can be counted with an 8-bit number. … When used this way, VarChar only uses the number of bytes + 1 to store your text, so you might as well set it to 255, unless you want a hard limit (like 50) on the number of characters in the field.
Is VARCHAR 255 bad?
5 Answers. Because 255 is now just an arbitrary choice for a VARCHAR length. Explanation: Prior to MySQL 5.0. … Now, however, you can go up to 65,535 characters on VARCHAR, so if you’re still using “255” then that seems arbitrary and not well thought out (or your schema is just old).
Which is faster CHAR or VARCHAR?
VARCHAR is used to store variable length character strings up to 4000 characters. But, remember CHAR is faster than VARCHAR – some times up to 50% faster.
Should I use CHAR or VARCHAR?
If you use char or varchar, we recommend to: Use char when the sizes of the column data entries are consistent. Use varchar when the sizes of the column data entries vary considerably. Use varchar(max) when the sizes of the column data entries vary considerably, and the string length might exceed 8,000 bytes.
What does VARCHAR 50 mean?
Varchar(50) stores a maximum of 50 characters. Varchar(max) stores a maximum of 2,147,483,647 characters. But, varchar(50) keeps the 50 character space even if you don’t store 50 characters. but varchar(max) is flexible to any size.
What is a VARCHAR value?
Values in VARCHAR columns are variable-length strings. The length can be specified as a value from 0 to 65,535. The effective maximum length of a VARCHAR is subject to the maximum row size (65,535 bytes, which is shared among all columns) and the character set used.
What is difference between CHAR VARCHAR and text?
CHAR items, which are fixed length, are the fastest to store and retrieve but can waste storage space. VARCHAR, a variable-length string, can be slower to store and retrieve but does not waste storage space. TEXT is a character BLOB that requires more storage space and I/O than the other two.