DECIMAL/NUMERIC, FLOAT and REAL

Differences among DECIMAL/NUMERIC, FLOAT and  REAL data types.

	DECIMAL/ NUMERIC	FLOAT	REAL
Bytes	5 bytes  - 17 bytes Maximum storage sizes vary, based on the precision Precision Storage bytes 1 - 9 5 10-19 9 20-28 13 29-38 17	4 bytes to 8 bytes depends on nvvalue nvalue Precision Storage size 1-24 7 digits 4 bytes 25-53 15 digits 8 bytes	8 bytes
Minimum Value	- 10^38 +1	- 1.79E+308 to -2.23E-308, 0	- 3.40E + 38 to -1.18E - 38, 0
Maximum Value	10^38 - 1	2.23E-308 to 1.79E+308	1.18E - 38 to 3.40E + 38
Max Length	38 digits The default precision is 18.
Format	DECIMAL(p) DECIMAL(p,s) p- precision s- scale	FLOAT(s)	REAL
Example	DECLARE @Decimal DECIMAL(38) = 92233720368547758079223372036854775807 SELECT @Decimal DECLARE @Decimal DECIMAL(38,2) = 122337203685477580792233720368547758.07 SELECT @Decimal DECLARE @Decimal DECIMAL(38,3) = 12233720368547758079223372036854775.807 SELECT @Decimal DECLARE @Numeric NUMERIC(38) = 92233720368547758079223372036854775807 SELECT @Numeric DECLARE @Numeric NUMERIC(38,2) = 122337203685477580792233720368547758.07 SELECT @Numeric DECLARE @Numeric NUMERIC(38,3) = 12233720368547758079223372036854775.807 SELECT @Numeric 54775 – Unit . – Decimal point 807 - Mantissa	DECLARE @Float FLOAT(53) = 92233720368547758079223372036854775807 SELECT @Float DECLARE @Float FLOAT(1) = 922337.47 PRINT @Float OUTPUT: 922338 DECLARE @Float FLOAT(1) = 922337.46 PRINT @Float OUTPUT: 922337	DECLARE @Real REAL = 92233720368547758079223372036854775807 SELECT @Real DECLARE @Real REAL = 922337.47 PRINT @Real OUTPUT: 922338 DECLARE @Real REAL = 922337.46 PRINT @Real OUTPUT: 922338

[ALSO READ A FEW MORE...]

• PRIMARY KEY vs UNIQUE KEY
• @@IDENTITY vs SCOPE_IDENTITY()
• SEQUENCE vs IDENTITY
• TINYINT vs SMALLINT
• SMALLINT vs INT
• INT vs BIGINT
• DECIMAL/NUMERIC vs FLOAT
• FLOAT vs REAL
• DECIMAL/NUMERIC vs REAL
• SMALLMONEY vs MONEY
• SMALLDATETIME vs DATETIME
• DATETIME vs DATETIME2(N)
• DATETIMEOFFSET vs DATE
• DATETIMEOFFSET vs TIME
• SYSUTCDATETIME vs SYSUTCDATE
• CHAR vs NCHAR
• CHAR or VARCHAR
• VARCHAR vs NVARCHAR
• VARCHAR vs VARCHAR(MAX)
• TEXT vs VARCHAR(MAX)
• BINARY vs VARBINARY
• IMAGE vs VARBINARY(MAX)
• CAST vs CONVERT
• LEN() vs DATALENGTH()
• UNION vs UNION ALL
• DELETE vs TRUNCATE
• Temporary Table vs Temporary Variable
• LEFT JOIN vs RIGHT JOIN
• LEFT OUTER JOIN vs RIGHT OUTER JOIN
• RAISERROR vs THROW
• Function vs Stored Procedure
• QUOTED_IDENTIFIER ON vs QUOTED_IDENTIFIER OFF