Validating null value in plsql
Validating null value in plsql - foxy brown dating kurupt
In fact, NULL is untyped in the SQL language, which is why you cannot validly use it in an equality comparison.
The orafaq link is still correct to say that NULL (which to me implies a "pure" NULL) is untyped, but perhaps they should add that it can be explicitly cast as a specific type.I wonder if the only impact casting a NULL can have is on functions like DECODE that derive the data type of their output from one of the inputs.Here is an excellent essay on the subject from a postgres perspective.Briefly summed up by saying nulls are treated differently depending on the context and don't make the mistake of making any assumptions about them.The answer is clearly maybe, which is neither true nor false.SQL courses meet the most demanding needs of the business world for advanced education in a cost-effective manner.
SQL courses are available immediately for IT professionals and can be taken without disruption of your workplace schedule or processes.Compared to traditional travel-based training, SQL saves time and valuable corporate resources, allowing companies to do more with less. As Fabricio Araujo hinted, NULL is not really a value like the number 4 or string 'bacon strips'.EDIT: In response to the comments I will add a little clarification to NULL as I have seen it used.While NULL really means "not set", in the context of this question I believe the above statement is correct.Note: Oracle Database currently treats a character value with a length of zero as null. For example, consider a query that averages the five values 1000, null, null, null, and 2000.