SQL Data Types

SQL data types are divided into five categories:

  1. Character/String Data Types
  2. Numeric Data Types
  3. Date/Time Data Types
  4. Binary Data Types
  5. Miscellaneous Data Types
SQL Data Types
SQL Data Types

1. Character/String Data Types

Character/Strings can be used to store strings like names, locations, etc. and even large text files.

Data Type Description
CHAR Maximum 8000 character long fixed length string
VARCHAR Maximum 8000 character long variable length string
VARCHAR(max) Maximum max character long variable length string
NCHAR Unicode Maximum 8000 character long fixed length string
NVARCHAR Unicode Maximum 8000 character long variable length string
NVARCHAR(max) Unicode Maximum max character long variable length string
TEXT Maximum 2GB sized variable length string

2. Numeric Data Types

Numeric data types can be used to store exact or decimal numeric data, from very small numbers in a bit or tinyint to very large numbers in a bigint.

Data Type Minimum Maximum
bit 0 1
tinyint 0 255
smallint -32,768 32,767
int -2,147,483,648 2,147,483,647
bigint -9,223,372,036,854,775,808 9,223,372,036,854,775,807
decimal -10^38 - 1 -10^38 - 1
real -3.40E + 38 3.40E + 38
numeric -10^38 +1 10^38 -1
float -1.79E + 308 1.79E + 308

3. Date/Time Data Types

Date/Time data types are used to store data and time objects. Storing a date as a date/type object instead of a string can make it very easy to work with data at a later point.

Data Type Description
Datetime Date and Time stored in the YYYY-MM-DD HH:MI:SS format
Date Date stored in the YYYY-MM-DD format
Time Time stored in the HH:MI:SS format
Timestamp Number of seconds passed stored since ‘1970-01-01 00:00:00’ UTC
Year Year stored in 2-digit (from 1970-2069) or 4-digit (from 1901 2155) format

4. Binary Data Types

Binary data types are used to store data in its binary form, instead of storing it as strings, which can be a big factor in saving space.

Data Type Description
BINARY Maximum length of 8000 bytes fixed binary
VARBINARY Maximum length of 8000 bytes variable binary
VARBINARY(max) Maximum length of max bytes fixed binary
NTEXT Maximum 2GB sized variable length binary

5. Miscellaneous Data Types

These data types are for special types of data as described below:

Data Type Description
CLOB Upto 2GB large character objects
BLOB For storing binary large objects
JSON For storing JSON objects
XML For storing XML objects

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