New Transact SQL Video Tutorial: 02 - Implicit Datatype Conversion and How SQL Server Converts Data in Expressions

02 - Implicit Datatype Conversion and How SQL Server Converts Data in Expressions - view details

This video is all about how SQL Server can automatically (implicitly) convert datatypes in expressions. For example, in the expression 'SELECT 1 + 10000 + 0.00', what will the return datatype be? 1 could be a BIT, a TINYINT, a SMALLINT, an INT, or a BIGINT - which is it? 10000 could be a SMALLINT, INT or BIGINT. 0.00 could be a DECIMAL, NUMERIC, FLOAT, REAL, MONEY, or SMALLMONEY.

Highlights from this video:

• In the expression, SELECT '123', is '123' a string or a number?
  
• In the expression, SELECT 2007/08/08, is the return type an INT, a DECIMAL, or a DATETIME?
  

an much more on datatypes

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So what is the answer to our question above? The answer is that if you just typed that expression in, your return type would be a FLOAT.

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• Source: http://www.LearnTransactSQL.com
• Category: Table Design - Datatypes, Constraints, IDENTITY Columns, Normalization, and More
• Skill Level: 200 (Beginner - Intermediate)
• Length: 11:00 (9.17MB)
• Applies to Versions: SQL Server - All Versions
• Full Details

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Keywords Associated with this video: data type conversion, cast, convert, cast and convert, numeric, decimal, varchar(max), nvarchar(max), float, real, int32, int64