Today is Monday let us start this week with interesting puzzle. Yesterday I had also posted quick question here: SQL SERVER – T-SQL Scripts to Find Maximum between Two Numbers
SQL SERVER – Explanation and Understanding NOT NULL Constraint
NOT NULL is integrity CONSTRAINT. It does not allow creating of the row where column contains NULL value. Most discussed question about NULL is what is NULL? I will not go in depth analysis it. Simply put NULL is unknown or missing data. When NULL is present in database columns,…
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SQL SERVER – Explanation and Comparison of NULLIF and ISNULL
Explanation of NULLIF
Syntax:
NULLIF ( expression , expression )
Returns a null value if the two specified expressions are equal. NULLIF returns the first expression if the two expressions are not equal. If the expressions are equal, NULLIF returns a null value of the type of the first expression. NULLIF is equivalent to a searched CASE function in which the two expressions are equal and the resulting expression is NULL.
SQL SERVER – LEN and DATALENGTH of NULL Simple Example
Simple but interesting – In recent survey I found that many developers making this generic mistake. I have seen following code in periodic code review. (The code below is not actual code, it is simple sample code) DECLARE @MyVar VARCHAR(10) SET @MyVar = NULL IF (LEN(@MyVar) = 0) … I…
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