Saturday, February 25, 2023

SQL Server - SQL Data Types

 

SQL Data Types




SQL Stores data into rows and columns. Each column must be assigned with a Name and data Type while creating a Table in database. Data Types such as String, Numeric, Date/Time.

MY SQL String Data Types

CHAR(Size)

It is used to specify a fixed length string that can contain numbers, letters, and special characters. Its size can be 0 to 255 characters. Default is 1.

VARCHAR(Size)

It is used to specify a variable length string that can contain numbers, letters, and special characters. Its size can be from 0 to 65535 characters.

BINARY(Size)

It is equal to CHAR() but stores binary byte strings. Its size parameter specifies the column length in the bytes. Default is 1.

VARBINARY(Size)

It is equal to VARCHAR() but stores binary byte strings. Its size parameter specifies the maximum column length in bytes.

TEXT(Size)

It holds a string that can contain a maximum length of 255 characters.

TINYTEXT

It holds a string with a maximum length of 255 characters.

MEDIUMTEXT

It holds a string with a maximum length of 16,777,215.

LONGTEXT

It holds a string with a maximum length of 4,294,967,295 characters.

ENUM(val1, val2, val3,...)

It is used when a string object having only one value, chosen from a list of possible values. It contains 65535 values in an ENUM list. If you insert a value that is not in the list, a blank value will be inserted.

SET( val1,val2,val3,....)

It is used to specify a string that can have 0 or more values, chosen from a list of possible values. You can list up to 64 values at one time in a SET list.

BLOB(size)

It is used for BLOBs (Binary Large Objects). It can hold up to 65,535 bytes.

 

My SQL Numeric Data Types

BIT(Size)

It is used for a bit-value type. The number of bits per value is specified in size. Its size can be 1 to 64. The default value is 1.

INT(size)

It is used for the integer value. Its signed range varies from -2147483648 to 2147483647 and unsigned range varies from 0 to 4294967295. The size parameter specifies the max display width that is 255.

INTEGER(size)

It is equal to INT(size).

FLOAT(size, d)

It is used to specify a floating point number. Its size parameter specifies the total number of digits. The number of digits after the decimal point is specified by d parameter.

FLOAT(p)

It is used to specify a floating point number. MySQL used p parameter to determine whether to use FLOAT or DOUBLE. If p is between 0 to24, the data type becomes FLOAT (). If p is from 25 to 53, the data type becomes DOUBLE().

DOUBLE(size, d)

It is a normal size floating point number. Its size parameter specifies the total number of digits. The number of digits after the decimal is specified by d parameter.

DECIMAL(size, d)

It is used to specify a fixed point number. Its size parameter specifies the total number of digits. The number of digits after the decimal parameter is specified by d parameter. The maximum value for the size is 65, and the default value is 10. The maximum value for d is 30, and the default value is 0.

DEC(size, d)

It is equal to DECIMAL(size, d).

BOOL

It is used to specify Boolean values true and false. Zero is considered as false, and nonzero values are considered as true.

 

My SQL DATE/TIME Data Types

DATE

It is used to specify date format YYYY-MM-DD. Its supported range is from '1000-01-01' to '9999-12-31'.

DATETIME()

It is used to specify date and time combination. Its format is YYYY-MM-DD hh:mm:ss. Its supported range is from '1000-01-01 00:00:00' to 9999-12-31 23:59:59'.

TIMESTAMP()

It is used to specify the timestamp. Its value is stored as the number of seconds since the Unix epoch('1970-01-01 00:00:00' UTC). Its format is YYYY-MM-DD hh:mm:ss. Its supported range is from '1970-01-01 00:00:01' UTC to '2038-01-09 03:14:07' UTC.

TIME()

It is used to specify the time format. Its format is hh:mm:ss. Its supported range is from '-838:59:59' to '838:59:59'

YEAR

It is used to specify a year in four-digit format. Values allowed in four digit format from 1901 to 2155, and 0000.

 

SQL SERVER String Data Types

char(n)

It is a fixed width character string data type. Its size can be up to 8000 characters.

varchar(n)

It is a variable width character string data type. Its size can be up to 8000 characters.

varchar(max)

It is a variable width character string data types. Its size can be up to 1,073,741,824 characters.

text

It is a variable width character string data type. Its size can be up to 2GB of text data.

nchar

It is a fixed width Unicode string data type. Its size can be up to 4000 characters.

nvarchar

It is a variable width Unicode string data type. Its size can be up to 4000 characters.

ntext

It is a variable width Unicode string data type. Its size can be up to 2GB of text data.

binary(n)

It is a fixed width Binary string data type. Its size can be up to 8000 bytes.

varbinary

It is a variable width Binary string data type. Its size can be up to 8000 bytes.

image

It is also a variable width Binary string data type. Its size can be up to 2GB.

 

SQL SERVER Numeric Data Types

bit

It is an integer that can be 0, 1 or null.

tinyint

It allows whole numbers from 0 to 255.

Smallint

It allows whole numbers between -32,768 and 32,767.

Int

It allows whole numbers between -2,147,483,648 and 2,147,483,647.

bigint

It allows whole numbers between -9,223,372,036,854,775,808 and 9,223,372,036,854,775,807.

float(n)

It is used to specify floating precision number data from -1.79E+308 to 1.79E+308. The n parameter indicates whether the field should hold the 4 or 8 bytes. Default value of n is 53.

real

It is a floating precision number data from -3.40E+38 to 3.40E+38.

money

It is used to specify monetary data from -922,337,233,685,477.5808 to 922,337,203,685,477.5807.

 

SQL SERVER DATE/TIME Data Types

datetime

It is used to specify date and time combination. It supports range from January 1, 1753, to December 31, 9999 with an accuracy of 3.33 milliseconds.

datetime2

It is used to specify date and time combination. It supports range from January 1, 0001 to December 31, 9999 with an accuracy of 100 nanoseconds

date

It is used to store date only. It supports range from January 1, 0001 to December 31, 9999

time

It stores time only to an accuracy of 100 nanoseconds

timestamp

It stores a unique number when a new row gets created or modified. The time stamp value is based upon an internal clock and does not correspond to real time. Each table may contain only one-time stamp variable.

 

 





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