What is the difference between the CHAR and the VARCHAR2 databases in SQL?

Differences: CHAR vs VARCHAR vs VARCHAR2 CHAR is different. CHAR does not need a size specified and has a default of 1. A size needs to be specified with VARCHAR/VARCHAR2 columns. CHAR will pad spaces to the right of strings to match the length of the column, while VARCHAR/VARCHAR2 does not.

What is the difference between CHAR & VARCHAR?

The basic difference between Char and Varchar is that: char stores only fixed-length character string data types whereas varchar stores variable-length string where an upper limit of length is specified.

What is VARCHAR2 data type?

The VARCHAR2 data type specifies a variable-length character string in the database character set. You specify the database character set when you create your database. When you create a table with a VARCHAR2 column, you must specify the column length as size optionally followed by a length qualifier.

Should I use VARCHAR or VARCHAR2?

VARCHAR is reserved to support distinction between NULL and empty string in future, as ANSI standard prescribes. VARCHAR2 does not distinguish between a NULL and empty string, and never will. If you rely on empty string and NULL being the same thing, you should use VARCHAR2.

What is the difference between simple view and complex view?

Simple View: A view based on only a single table, which doesn’t contain GROUP BY clause and any functions. Complex View: A view based on multiple tables, which contain GROUP BY clause and functions.

What is the difference between VARCHAR and CHAR in mysql?

A CHAR field is a fixed length, and VARCHAR is a variable length field. This means that the storage requirements are different – a CHAR always takes the same amount of space regardless of what you store, whereas the storage requirements for a VARCHAR vary depending on the specific string stored.

What is the difference between CHAR and Nchar?

n-char : A n-char is also a string of words that can store unicode data. nchar stands for national character. It takes up two bytes to store the data and can store upto 4000 chars. Unicode data refers to a universal coding standard for letters and other data.

Is VARCHAR2 alphanumeric?

Character Datatypes The CHAR and VARCHAR2 datatypes store alphanumeric data. Character data is stored in strings, with byte values corresponding to the character encoding scheme (generally called a character set or code page).

Why are using NVARCHAR2 in Oracle?

The NVARCHAR2 datatype is a Unicode-only datatype. When you create a table with an NVARCHAR2 column, you supply the maximum number of characters it can hold. Oracle subsequently stores each value in the column exactly as you specify it, provided the value does not exceed the maximum length of the column.

Does MySQL have VARCHAR2?

Note: The ENUM and SET data types have no direct mapping in Oracle. SQL Developer maps ENUM columns in MySQL to VARCHAR2 columns in Oracle….2.3. 2 Default Data Type Mappings.

MySQL Data Type	Oracle Data Type
TINYBLOB	RAW
TINYINT	NUMBER(3, 0)
TINYTEXT	VARCHAR2
VARCHAR	VARCHAR2, CLOB

What is the difference between simple and a complex table?

Simple Table- It shows data relating to only one characteristic of data. For example- a table showing total number of students in a college in different years. Complex Table- It shows data relating to two or more characteristics of the data.

What is view in SQL and how it is defined?

In SQL, a view is a virtual table based on the result-set of an SQL statement. A view contains rows and columns, just like a real table. You can add SQL statements and functions to a view and present the data as if the data were coming from one single table. A view is created with the CREATE VIEW statement.