Pl/sql case is null

Because the ELSE clause is optional, you can skip it. The following example illustrates how to use the searched CASE statement to calculate sales commission based on sales revenue. The ELSE statement clause will also never execute. Marcus in the comments below suggests creating an isEqual function that handles this for you. Here's the implementation of Marcus's isequal function for dates:.

It is also a statement , albeit a ''no-op" no operation -it only passes control to the next statement. Here are two examples. Null values can be a real pain. They can cause unexpected failures and exceptions in your algorithms.

They can mess up queries, either returning rows you didn't want or excluding rows when you want them. So, the first thing to do is to decide very carefully where and when you want to allow nulls. If a column's value should never be null, then define it that way. If you are writing a subprogram procedure or function and a parameter's value should never be null, you cannot add NOT NULL to the parameter definition.

Instead, you will need to do one of the following:. Use a datatype for the parameter that cannot be null. See the examples below. Add code to your subprogram to check or assert that the actual argument value is not null.

Then, you declare your own subtype and make that new datatype not-nullable. Let's take a look:. Note that the exceptions raised above occur before the procedure is even executed, so the exception handler of the procedure cannot trap the exception you do not see "Error! That may be just what you want. But if you cannot use a NOT NULL datatype for your parameter or you want to be able to trap the exception inside the subprogram, then you should write your own assertion code that runs right at the top of the subprogram.

Here's an example:. Sign in. United States English. Ask a question. Quick access. Search related threads. ID - join the two tables in the subquery, and join the subquery to the main query. Sign up or log in Sign up using Google. Sign up using Facebook. Sign up using Email and Password. Post as a guest Name. Email Required, but never shown. The Overflow Blog.

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