using JDBC

These instructions were initially written by ChatGPT, then edited by the instructor.

Creating a PostgreSQL JDBC project in VS Code

Follow these steps to set up a new Java project in VS Code to interact with PostgreSQL via JDBC:

1. Install VS Code extensions
   Make sure you have the Java Extension Pack installed in VS Code.
   This gives you project support, autocompletion, and debugging.

2. Create a new folder for your project
   For example: QueryExecutorProject/

3. Inside the project folder, create and populate subfolders:

   Create a src/ folder and lib/ folder

   • Put your source file QueryExecutor.java into the src/ folder. An even simpler file which may be useful for debugging is DbDemo.java
   • Put the external JAR postgresql-42.7.7.jar into the lib/ folder.
4. Open the project folder in VS Code
   • In VS Code, go to File → Open Folder… and select QueryExecutorProject.
5. Tell VS Code about your JAR files
   • In the project root, create a .vscode folder (if it doesn’t exist).
   • Inside it, create a file called settings.json with the following contents:

    {
      "java.project.referencedLibraries": [
        "lib/**/*.jar"
      ]
    }
   

   This tells VS Code to include all JARs in the lib/ folder.

6. Edit Postgres settings in source code
   • Open QueryExecutor.java.
   • Edit values such as PG_PASSWORD, PG_PORT_NUMBER, schema_name to match your installation of Postgres and the schema you wish to query.
7. Run the program
   • Open QueryExecutor.java.
   • You should see a Run and Debug button appear above the main method.
   • Click Run, and VS Code will compile and run the project, using the JAR on the classpath.

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At this point, your QueryExecutor.java can import and use classes from the external JAR, and VS Code will handle both editing and running.