What is meant by VARCHAR?

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.

Is VARCHAR a string?

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.

What is meant by VARCHAR 20?

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 is 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. See Section 8.4.

Should I use VARCHAR or string?

Use varchar if you want to have a length constraint. Use string if you don’t want to restrict the length of the text.

What does PK mean in database?

Primary Keys. A primary key is the column or columns that contain values that uniquely identify each row in a table. A database table must have a primary key for Optim to insert, update, restore, or delete data from a database table.

What is int MySQL?

In MySQL, INTEGER (INT) is a numeric value without a decimal. It defines whole numbers that can be stored in a field or column. In addition, MySQL supports the display_width attribute (for example, INT(1)) and the ZEROFILL attribute, which automatically adds zeros to the value depending on the display width.

What does Nchar 10 mean?

nchar(10) is a fixed-length Unicode string of length 10. nvarchar(10) is a variable-length Unicode string with a maximum length of 10. Typically, you would use the former if all data values are 10 characters and the latter if the lengths vary.

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 difference between BIGINT and int?

The int type takes 4 byte signed integer i.e. 32 bits ( 232 values can be stored). The BigInt type takes 8 byte signed integer i.e. 64 bits (264 values can be stored).

What means int 11 in MySQL?

in int(11), 11 is the display width of the integer column, unlike the characters columns where the number means number of character that can be stored. int(11) – The number in the parenthesis i.e () does not determines the max and min values that can be stored in the integer field.

What is int SQL?

The int data type is the primary integer data type in SQL Server. The bigint data type is intended for use when integer values might exceed the range that is supported by the int data type.

What is float and integer?

Integers and floats are two different kinds of numerical data. An integer (more commonly called an int) is a number without a decimal point. A float is a floating-point number, which means it is a number that has a decimal place. Floats are used when more precision is needed.

Can BIGINT have decimals?

BIGINT is to store large integers from negative 263 through positive 263 – 1. The storage size is eight bytes. BIGINT is intended for special cases where INTEGER range is”not sufficient. DECIMAL Valid values are in the range from negative 1038 +1 through positive 1038 – 1.

What is decimal SQL?

Use the SQL Server DECIMAL data type to define columns that have fixed precision and scale. … When defining, the DECIMAL data type provides both precision and scale. The precision defines the total number of decimal digits to store within the number. This includes digits to the left and right of the decimal.

What is a float Java?

A float data type in Java stores a decimal value with 6-7 total digits of precision. … The default value of a float in Java is 0.0f. Float data type is used when you want to save memory and when calculations don’t require more than 6 or 7 digits of precision.

What is difference between int and double?

The int and double are major primitive data types. The main difference between int and double is that int is used to store 32 bit two’s complement integer while double is used to store 64 bit double precision floating point value. In brief, double takes twice memory space than int to store data.

Can integers be negative?

Yes, a negative number can also be an integer, given that it should not have a decimal or fractional part. For example: Negative numbers: -2, -234, -71, etc are all integers.