In relational database, we store data in tabular form where data is divided into columns. Each column has a name and a data type which shows what type of data is going to store in that column. Below are the data types which are mostly used in SQL server.
CHARACTER(n) Character string of fixed length n
VARCHAR(n) Character string of variable length with maximum length n
VARCHAR(MAX) Character string of variable length with maximum length can exceed 8000 byes
NCHAR(n) Fixed-length Unicode string data where n defines the string length and must be a value from 1 through 4,000
NVARCHAR(n) Variable length Unicode string data where n defines the string length and must be a value from 1 through 4,000
NVARCHAR(MAX) Variable length Unicode string data where MAX indicates that the maximum storage size is 2^31-1 bytes (2 GB)
BINARY(n) Binary string of fixed length n
BOOLEAN It stores TRUE or FALSE values
VARBINARY(n) Binary string of variable length with maximum length n
NTEXT Variable-length Unicode data with a maximum string length of 2^30 - 1 (1,073,741,823) bytes
TEXT Variable-length non-Unicode data in the code page of the server and with a maximum string length of 2^31-1 (2,147,483,647)
IMAGE Variable-length binary data from 0 through 2^31-1 (2,147,483,647) bytes.
INTEGER Or Int A 32-bit signed integer value having range of INTEGER is -2147483648 to 2147483647
SMALLINT A 16-bit signed integer value having range of SMALLINT is -32768 to 32767.
BIGINT A 64-bit signed integer value having range of BIGINT is -9223372036854775808 to 9223372036854775807
DECIMAL(p,s) Exact numerical, precision p, scale s. For Example, Decimal(5,3) means 22.212
NUMERIC(p,s) Exact numerical, precision p, scale s. (Same as DECIMAL)
REAL Approximate numerical, mantissa precision 7
FLOAT Approximate numerical, mantissa precision 16
DOUBLE Approximate numerical, mantissa precision 16
DATE It stores year/month/day values
TIME It stores hour/minute/second values
TIMESTAMP It stores year/month/day/hour/minute/second values
XML It stores XML data
CHARACTER(n) Character string of fixed length n
VARCHAR(n) Character string of variable length with maximum length n
VARCHAR(MAX) Character string of variable length with maximum length can exceed 8000 byes
NCHAR(n) Fixed-length Unicode string data where n defines the string length and must be a value from 1 through 4,000
NVARCHAR(n) Variable length Unicode string data where n defines the string length and must be a value from 1 through 4,000
NVARCHAR(MAX) Variable length Unicode string data where MAX indicates that the maximum storage size is 2^31-1 bytes (2 GB)
BINARY(n) Binary string of fixed length n
BOOLEAN It stores TRUE or FALSE values
VARBINARY(n) Binary string of variable length with maximum length n
NTEXT Variable-length Unicode data with a maximum string length of 2^30 - 1 (1,073,741,823) bytes
TEXT Variable-length non-Unicode data in the code page of the server and with a maximum string length of 2^31-1 (2,147,483,647)
IMAGE Variable-length binary data from 0 through 2^31-1 (2,147,483,647) bytes.
INTEGER Or Int A 32-bit signed integer value having range of INTEGER is -2147483648 to 2147483647
SMALLINT A 16-bit signed integer value having range of SMALLINT is -32768 to 32767.
BIGINT A 64-bit signed integer value having range of BIGINT is -9223372036854775808 to 9223372036854775807
DECIMAL(p,s) Exact numerical, precision p, scale s. For Example, Decimal(5,3) means 22.212
NUMERIC(p,s) Exact numerical, precision p, scale s. (Same as DECIMAL)
REAL Approximate numerical, mantissa precision 7
FLOAT Approximate numerical, mantissa precision 16
DOUBLE Approximate numerical, mantissa precision 16
DATE It stores year/month/day values
TIME It stores hour/minute/second values
TIMESTAMP It stores year/month/day/hour/minute/second values
XML It stores XML data
