Dynamic PL/SQL Procedures: What They Are and How to Use Them

In the realm of databases, especially with Oracle's PL/SQL, it is entirely feasible and exhilarating as a means of making your applications more intelligent, adaptable, and easier to maintain. 

Also Read: How to Write Efficient MySQL Queries for Large Datasets

Welcome to the dynamic PL/SQL Procedures universe!  

Whether you identify as an up-and-coming programmer, an enthusiast of data, or a person just trying to navigate your way through Oracle's complicated database, this blog will be explaining everything you need to understand to navigate dynamic PL/SQL, including what dynamic PL/SQL is, how it operates, and why it is essential to care about. 

Let's get started. 

What Are Dynamic PL/SQL Procedures? 

PL/SQL (Procedural Language/SQL) is a programming language designed to perform work within Oracle databases. With PL/SQL, you can write code to run every day "CRUD" operations like inserting data, updating tables, or reliably conducting transactions. 

However, the traditional PL/SQL method is static. This means you write code, compile it, and then it will execute exactly as you wrote it, with no extra or missing lines of code. 

Dynamic PL/SQL adds an incredible new layer to this. Dynamic PL/SQL allows you to write and execute PL/SQL statements at runtime. Dynamic PL/SQL allows your code to change based on real-time variables, inputs, or simply system conditions. 

How does this work? Simply through the use of a command called EXECUTE IMMEDIATE. EXECUTE IMMEDIATE allows you to execute dynamic SQL statements, i.e., SQL statements that were not known until the code executed. 

Why Use Dynamic PL/SQL Procedures? 

You might be asking yourself, "Why not just use static PL/SQL?" That's a fair question - the answer ultimately has to do with the flexibility and automation features of Dynamic PL/SQL.  

Here are a couple of examples of when to use Dynamic PL/SQL: 

• When you need to operate against tables that only exist at runtime. 

• When you are altering a column structure dynamically. 

• When you build something reusable, it does things like generate SQL at runtime. 

• When you need to run automated administrative tasks, such as backups, logs, or batch processes. 

In enterprise applications, where scalability and automation in a least effort way make this more manageable for you, Dynamic PL/SQL is very useful.  

For example, Fusion Software Institute not only teaches students theory, but they also teach them how to solve real problems using dynamic SQL that would not be solved as plain SQL in many cases. 

Real-World Applications of Dynamic PL/SQL  

Now let’s explore a few real-world examples where dynamic procedures can be lifesavers.  

1. Dynamic Accessing Tables  

Let us assume that you are developing a reporting module that produces reports using the table name provided by the user.  

Static SQL is not going to work in your case; you would have to create separate procedures for each and every table.  

But with dynamic PL/SQL, you can access the table name through a variable to execute the correct query at runtime.  

2. Automated Auditing and Logging  

Do you need to log every change you make to the dozens of different tables? It would be tedious to have to write triggers or create procedures to take care of each instance.  

But, with dynamic PL/SQL, you can simply loop through the table names to automatically generate a SQL statement to log the action, all through a single generic procedure.  

3. DDL Operations  

Have a requirement to create or modify database objects on the fly? DDL (Data Definition Language) statements such as CREATE, DROP, or ALTER can be defined dynamically through EXECUTE IMMEDIATE, which will help in automating database administration functions. 

4. Conditional Execution