Use the SQL Server DECIMAL data type to define columns that have fixed precision and scale.  Unlike FLOAT, DECIMAL data type has fixed decimal places.  Use DECIMAL data type and NUMERIC data type keywords interchangeably to define the type.  DECIMAL(precision, scale)  When defining, the DECIMAL data type provides both precision and scale.  The precision defines the total number of decimal digits to store…

Use the SQL Server FLOAT data type to define columns, variables, and parameters storing floating-point numbers.  By floating point, we mean, numbers that have no fixed decimal place.  Consider using SQL FLOAT when working with scientific values.  Unlike DECIMAL, the FLOAT type handles a wide range of numbers:  Here is the range expressed in scientific notation:  Sign  Max Value  Minimum Value  Negative  – 1.79E+308  -2.23E-308  Positive  1.79E+308 …

Use the SQL Server VARCHAR data type to define columns, variables, and parameters variable length characters.  VARCHAR types are variable in length.  They do not take up more memory than the characters stored.  This differs from the CHAR type, which always occupies the full amount defined.  The VARCHAR type stores up to 8000 characters with each character taking one byte. …

Use the SQL Server INT data type to define columns, variables, and parameters storing whole numbers.  The INT data type stores a number in the range -2,147,483,648 to 2,147,483,647.  If you need to store a larger integer value, consider using BIGINT.  In addition to being used for numbers, INT is also used to define primary and foreign keys.  Use it to create…

Use the SQL Server DATETIME data type to define columns, variables, and parameters storing a date with the time of day.  The DATETIME data type stores both the date and time.  The allowed dates span from January 1, 1753 to December 31, 9999.  The time component ranges from 00:00:00 through 23:59:59.997.  Here is an example of a valid DATETIME value:  2017-11-23 11:30:34  Which represents November, 23rd 2017…

Use the SQL Server NVARCHAR data type to define columns, variables, and parameters variable length characters.  NVARCHAR types are variable in length.  They take up more memory than the characters stored.  This differs from the CHAR type, which always occupies the full amount defined.  They store up to 4000 characters with each character taking two bytes and are is well suited for storing extended character…

In SQL the columns of a table are defined to store a specific kind of value such as numbers, dates, or text; these are called data types.  With over thirty types of SQL server data types to choose from, data types can seem intimidating, but in reality, there are just a few commonly used in…