An Introduction to PL/SQL

Just getting started with PL/SQL? You will find PL/SQL to be a very readable and accessible programming language. You'll be productive in a very short amount of time!

I offer this post as a quick way to access a number of resources that will provide a nicely-paced introduction to this powerful database programming language. Of course, it helps a lot to know SQL, too, so check out the Other Useful Links at the bottom of the post.

I wrote a series of "PL/SQL 101" articles for Oracle Magazine several years ago. Here's a convenient index to all those articles:

1. Building with Blocks - an overview of PL/SQL, followed by coverage of some fundamentals
2. Controlling the Flow of Execution - conditional statements and loops
3. Working with Strings
4. Working with Numbers
5. Working with Dates
6. Error Management
7. Working with Records
8. Working with Collections
9. Bulk Processing with BULK COLLECT and FORALL
10. The Data Dictionary: Make Views Work for You
11. Wrap Your Code in a Neat Package
12. Working with Cursors

I added several "PL/SQL 101" posts on this blog as well:

Nulls in PL/SQL
Declaring variables and constants
Writing conditional logic in PL/SQL

Other Useful Links

Oracle PL/SQL home page - latest news, links to lots of other resources

Oracle SQL home page - 'cause what's PL/SQL without SQL?

Database for Developers: Fundamentals - an Oracle Dev Gym class that introduces to fundamental relational database concepts

Database for Developers: Next Level - an Oracle Dev Gym class that makes sure you have a solid foundation in basic SQL operations

Introduction to PL/SQL - FREE online class from the Oracle Learning Library

PL/SQL Tutorial from DatabaseStar - a free seven-part tutorial on basic PL/SQL concepts, packed with easy to follow examples.

Comments

Why DBMS_OUTPUT.PUT_LINE should not be in your application code

A database developer recently came across my Bulletproof PL/SQL presentation, which includes this slide. That first item in the list caught his attention: Never put calls to DBMS_OUTPUT.PUT_LINE in your application code. So he sent me an email asking why I would say that. Well, I suppose that is the problem with publishing slide decks. All the explanatory verbiage is missing. I suppose maybe I should do a video. :-) But in the meantime, allow me to explain. First, what does DBMS_OUTPUT.PUT_LINE do? It writes text out to a buffer, and when your current PL/SQL block terminates, the buffer is displayed on your screen. [Note: there can be more to it than that. For example, you could in your own code call DBMS_OUTPUT.GET_LINE(S) to get the contents of the buffer and do something with it, but I will keep things simple right now.] Second, if I am telling you not to use this built-in, how could text from your program be displayed on your screen? Not without a lot o...

How to Pick the Limit for BULK COLLECT

This question rolled into my In Box today: In the case of using the LIMIT clause of BULK COLLECT, how do we decide what value to use for the limit? First I give the quick answer, then I provide support for that answer Quick Answer Start with 100. That's the default (and only) setting for cursor FOR loop optimizations. It offers a sweet spot of improved performance over row-by-row and not-too-much PGA memory consumption. Test to see if that's fast enough (likely will be for many cases). If not, try higher values until you reach the performance level you need - and you are not consuming too much PGA memory. Don't hard-code the limit value: make it a parameter to your subprogram or a constant in a package specification. Don't put anything in the collection you don't need. [from Giulio Dottorini] Remember: each session that runs this code will use that amount of memory. Background When you use BULK COLLECT, you retrieve more than row with each fetch, ...

Table Functions, Part 1: Introduction and Exploration

Please do feel encouraged to read this and my other posts on table functions, but you will learn much more about table functions by taking my Get Started with PL/SQL Table Functions class at the Oracle Dev Gym. Videos, tutorials and quizzes - then print a certificate when you are done! Table functions - functions that can be called in the FROM clause of a query from inside the TABLE operator - are fascinating and incredibly helpful constructs. So I've decided to write a series of blog posts on them: how to build them, how to use them, issues you might run into. Of course, I am not the first to do so. I encourage to check out the documentation , as well as excellent posts from Adrian Billington (search for "table functions") and Tim Hall . Adrian and Tim mostly focus on pipelined table functions, a specialized variant of table functions designed to improve performance and reduce PGA consumption. I will take a look at pipelined table functions in the latter part...

Obsessed with Oracle PL/SQL

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