If value is null then oracle

Note that NULL is not the same as an empty data string or the numerical value '0'. It prevents to bring data when I don't want data, but just the exist status. This function is used to replace NULL value with another value. The Oracle NVL function allows you to replace null with a more meaningful alternative in the results of a query. The NVL function accepts two arguments. If e1 evaluates to null, then NVL function returns e2. If e1 evaluates to non-null, the NVL function returns e1. Click in the column value you want to set to null.

Select the value and delete it. Hit the commit button green check-mark button. SQL has the is [not] null predicate to test if a particular value is null. Data types that can be used are date, character and number.

Data type must match with each other i. Is null in case statement Oracle? The list must consist of at least 2 values. When a column in a table is defined there is the possibility to have a default value for this column whenever it is inserted without a value.

This is done on insert only. If you modify the default during the life of the table, the new default will be applied from that moment on. Now how do you make sure a default is applied to columns already NULL? It can for instance be used to build a decision table. Consider the following decision table:. The column in our table just holds the code instead of the value. If we want to represent the value instead of the code we could write a query like this:.

The case statement has two flavors. The simple case and the searched case. In the simple case the expression is written only once and depending on the result of this expression one of the possible cases is being used.

This can be helpful when you need to choose from a set of distinct values. In the searched case every case has its own expression. This can for instance be helpful when using ranges. The else clause is optional. NULL values are one of the most mind-boggling values in the Oracle database. Find out more. Improve this question. XING - Seriously? Show 5 more comments. Active Oldest Votes.

Improve this answer. Ponder Stibbons Ponder Stibbons Will the second query be able to use column indexes or would the use of a function cause full table scans? Is that the desired behavior? The correct answer is the first version you proposed.

MT0 - why only the second query? You may ask the same question about the first one too. The answer is the same. I made short test and index was used in nvl version. The first version is better than the second, but "ability to use an index" is not among the reasons.

Show 2 more comments. NVL will be your friend here. Dessma Dessma 2 2 silver badges 11 11 bronze badges. UsagiMiyamoto - Why? Basically, over large datasets an NVL will be slower. Is that the desired result? Probably not! Add a comment.