如何通过Teiid虚拟存储过程同时调用Oracle和MySQL存储过程？

Hey there! Let's get your combined virtual procedure up and running. Your initial syntax idea is actually on the right track—Teiid absolutely supports chaining multiple stored procedure calls in a single virtual procedure. Here's a breakdown of how to make this work, both via direct SQL and using Teiid Designer.

1. Correct Virtual Procedure Syntax #

First, let's refine your SQL example. The core structure you have is valid, but we’ll make sure it’s properly formatted and covers key considerations:

CREATE VIRTUAL PROCEDURE myCombinedProc () 
RETURN () 
BEGIN
    -- Execute Oracle stored procedure
    CALL MyOracleProc();
    -- Execute MySQL stored procedure
    CALL MySQLProc();
END

Key Notes: #

• Ensure Procedure References Are Valid: Make sure MyOracleProc and MySQLProc are correctly mapped in your VDB. These should be physical procedures from your Oracle and MySQL source models, which are included in your VDB.
• Handling Parameters: If your stored procedures require input/output parameters, define them in the virtual procedure signature and pass them through. For example:

  CREATE VIRTUAL PROCEDURE myCombinedProc (IN customerId integer, IN customerName string) 
  RETURN () 
  BEGIN
      CALL MyOracleProc(customerId, customerName);
      CALL MySQLProc(customerId, customerName);
  END
  

• Transaction Behavior: By default, each CALL runs in its own transaction. If you need atomicity (both procedures succeed or fail together), ensure your data sources support XA transactions and configure Teiid to use XA. You can wrap the calls in a transaction block explicitly if needed:

  CREATE VIRTUAL PROCEDURE myCombinedProc () 
  RETURN () 
  BEGIN
      START TRANSACTION;
      CALL MyOracleProc();
      CALL MySQLProc();
      COMMIT;
  END
  

2. Using Teiid Designer to Build the Virtual Procedure #

If you prefer a GUI approach, Teiid Designer makes this straightforward:

• Open your Teiid Designer project and navigate to your VDB.
• Create or select a Virtual Model (where your combined procedure will live).
• Right-click the virtual model > New > Virtual Procedure.
• In the wizard:
  • Name your procedure (e.g., myCombinedProc).
  • Set the return type to None if you don’t need to return data.
  • Add any input/output parameters your procedures require.
• In the procedure editor, use the Palette to add two CALL operations. For each:
  • Select the corresponding physical stored procedure from your Oracle/MySQL source models.
  • Map any parameters if needed.
• Save the procedure, then deploy your updated VDB. You can now call myCombinedProc just like any other stored procedure in Squirrel or your client tool.

3. Troubleshooting Tips #

• Verify Procedure Visibility: Double-check that your physical stored procedures are included in the VDB and that the virtual model has access to them.
• Check Permissions: Ensure the Teiid user account has execute permissions for both the physical procedures and the new virtual procedure.
• Test Individually First: Confirm each stored procedure still works independently before combining them—this helps isolate issues if the combined procedure fails.

内容的提问来源于stack exchange，提问作者Adinath