Question

I’m new to Oracle, so bear with me on this – I’ll do as best I can.

I’m writing a stored procedure. After the AS statement completes, I have the following code:

BEGIN
IF v_Node = NULL
    BEGIN
      SET v_Node = LEFT(v_Tag, INSTR('.', v_Tag)-1)
      SET v_Node = (SELECT v_NodeId FROM DBO.nodes WHERE Node = v_Node)
    END

which we I compile spits out the following error:

Error(23,5): PLS-00103: Encountered the symbol "BEGIN" when expecting one of the following: * & - + / at mod remainder rem then <an exponent (**)> and or || multiset

Can anyone help with this?
Cheers

Answer 1

I suspect that you want something like

CREATE OR REPLACE PROCEDURE <<procedure name>>( <<parameter list>> )
AS
  <<variable declarations>>
BEGIN
  IF v_Node IS NULL
  THEN
    v_Node := substr( v_tag, 1, instr( '.', v_tag ) - 1 );
    SELECT v_NodeId -- Is v_NodeID really a column in dbo.nodes?  The naming 
                    -- convention would imply that it is a local variable in 
                    -- which case the SELECT statement doesn't make a lot of 
                    -- sense.
      INTO v_node
      FROM dbo.nodes
     WHERE node = v_node;
  END IF;

  <<more code>>
END;

The explanation

1. No value is ever equal to NULL, not even another NULL. You need to use the IS NULL operator.
2. Oracle does not have a LEFT function. You probably want SUBSTR.
3. SET is not a valid PL/SQL operator. You can use the := operator to assign the result of an expression to a variable. And you can use SELECT ... INTO to assign the result of a SQL query to a local variable.

The remaining issues

1. It seems odd that you appear to be using the same local variable v_Node both to assign the Node string you want to search for and to hold the presumably numeric v_NodeId that you select from the table. If that is really your intention, you would want separate variables.
2. The SELECT statement that you wrote doesn’t make sense. If v_NodeId is a local variable, as the naming convention implies, it doesn’t make sense to select it from the dbo.nodes table. It would seem more likely that you want to select the NodeId (assuming that is a column in dbo.nodes).