What does VARCHAR stand for?
character data
As the name suggests, varchar means character data that is varying. Also known as Variable Character, it is an indeterminate length string data type. It can hold numbers, letters and special characters.
What is a VARCHAR field?
A variable character field (varchar) is a data type which can contain any type of data: numeric, characters, spaces or punctuation. Depending on the database, the data type is capable of storing values up to its maximum size.
What is VARCHAR vs text?
Some Differences Between VARCHAR and TEXT The VAR in VARCHAR means that you can set the max size to anything between 1 and 65,535. TEXT fields have a fixed max size of 65,535 characters. A VARCHAR can be part of an index whereas a TEXT field requires you to specify a prefix length, which can be part of an index.
How long is varchar?
0 to 65,535
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 are the commands of DDL?
Data Definition Language (DDL) commands:
- CREATE to create a new table or database.
- ALTER for alteration.
- Truncate to delete data from the table.
- DROP to drop a table.
- RENAME to rename a table.
What is Tinytext in MySQL?
The TINYTEXT data object is the smallest of the TEXT family and is built to efficiently store short information strings. This type can store up to 255 bytes (expressed as 2^8 -1) or 255 characters and requires a 1 byte overhead.
What does FK stand for database?
Foreign keys (FK) – values match a primary or alternate key inherited from some other table.
What is PK and FK in SQL?
Foreign Key. Primary key uniquely identify a record in the table. Foreign key is a field in the table that is primary key in another table. Primary Key can’t accept null values. Foreign key can accept multiple null value.
What are the disadvantages of Using VARCHAR?
Varchar Nvarchar; Advantages: Occupies less physical storage space as it’s storage length is equal to the actual length of the data + 2 bytes. Supports multiple languages and locales. So any Unicode data can be stored without worrying about conversion. Disadvantages: Need to use conversion technique if you want to store Unicode date in varchar column.
What’s the difference between Char and VARCHAR?
Although char and varchar are character data fields,char is a fixed length data field and varchar is a variable size data field.
What is the major difference between VARCHAR2 and Char?
Let’s take a look at the differences between these three data types. VARCHAR and VARCHAR2 are exactly the same. CHAR is different. CHAR has a maximum size of 2000 bytes, and VARCHAR/VARCHAR2 has a maximum size of 4000 bytes (or 32,767 in Oracle 12c) CHAR does not need a size specified and has a default of 1.
What is the difference between varchar and VARCHAR2 in Oracle?
The difference between VARCHAR and VARCHAR2 in Oracle is that VARCHAR is an ANSI-standard data type that supports a distinction between NULL and empty strings. Oracle has not yet implemented this distiction, so at the moment, VARCHAR and VARCHAR2 are the same.