Write a block of code that does the following:. Sound complicated? It is, sort of. Notice in the block below that the three element values are , and And those elements in turn have the values , and Have you got a dynamic update, insert or delete sitting inside a loop? Don't worry Let's take a look. The bottom line: if you can execute the DML statement statically, you can do it dynamically, too.
Note that your solution might not match mine exactly, and that's just fine - as long as you use the bulk processing features correctly.
I offer two solutions below. The second uses a collection of records. Both work just fine! Again, in two forms: one using two separate collections, the other using a collection of records. The Oracle Dev Gym offers multiple choices quizzes, workouts and classes on a wide variety of Oracle Database topics. They are a great follow-up and reinforcement for this tutorial. Tim Hall of oracle-base. After you read his article and check out the documentation, it's time to take four quizzes written by Steven Feuerstein to test your knowledge of this feature.
Check out the documentation for more details. Live SQL. Module 1. If when you run code, you see this error ORA table or view does not exist So at the end of most of the modules, you will find: Fill in the Blanks: partially-written code that you need to finish up, that reinforces the content of that module.
Module 2. When I execute this block Module 3. Possible Solutions Generally, the way to improve performance over row-by-row context switching is to not perform row-by-row DML operations. Module 4. You can fetch into individual collections one for each expression in the SELECT list or a single collection of records.
The collection is always populated densely, starting from index value 1. If no rows are fetched, then the collection is emptied of all elements. COUNT ; END; If you do not want to retrieve all the columns in a table, create your own user-defined record type and use that to define your collection.
Module 5. When empty, terminate. These two approaches are shown below. Module 6. You cannot modify this number. That is, fetching rows with each fetch will usually give you sufficient improvements in performance over row-by-row fetching.
If you are fetching a very large number of rows, such as might happen with data warehouse processing or a nightly batch process, then you should experiment with larger LIMIT values to see what kind of "bang for the buck" you will get. Run the following code to see how optimization affects cursor FOR loop performance. Module 7. Module 8. Module 9. Initialize the nested table with two departments.
In this simplest of all cases, it looks just like a numeric FOR loop header, iterating from 1 to the number of elements in the nested table. Display the number of rows modified by the entire FORALL statement, and then rollback changes so that the table is left intact for the next example. Feel free to ask questions on our Oracle forum. Verify experience! Anyone considering using the services of an Oracle support expert should independently investigate their credentials and experience, and not rely on advertisements and self-proclaimed expertise.
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If you find an error or have a suggestion for improving our content, we would appreciate your feedback. Just e-mail: and include the URL for the page. All rights reserved by Burleson. Oracle Bulk Collect One method of fetching data is an Oracle bulk collect. Search BC Oracle Sites. In particular, this error occurs when a row-level trigger attempts to read or write the table from which the trigger was fired. Fortunately, the same restriction does not apply in statement-level triggers.
In this post, I demonstrate the kind of scenario that will result in an ORA errors. I then show the "traditional" solution, using a collection defined in a package. Then I demonstrate how to use the compound trigger, added in Oracle Database 11g Release1, to solve the problem much more simply. All the code shown in this example may be found in this LiveSQL script. Read more. September 18, Hope you enjoyed reading. Log in to leave a comment. Sign in. Log into your account. Forgot your password?
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