Oracle PL/SQL - PL SQL Statement Inquiry Directives

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Introduction

An inquiry directive provides information about the compilation environment.

Syntax 

$$name

An inquiry directive typically appears in the boolean_static_expression of a selection directive.

The predefined inquiry directives are:

Inquiry Directives
 Description
$$PLSQL_LINE


 A PLS_INTEGER literal whose value is the number of the source line on which the directive appears in the current PL/SQL unit.
For example:
$IF $$PLSQL_LINE = 32 $THEN ...
$$PLSQL_UNIT



 A VARCHAR2 literal that contains the name of the current PL/SQL unit.
If the current PL/SQL unit is an anonymous block, $$PLSQL_UNIT contains a NULL value.
For example:
$IF $$PLSQL_UNIT IS NULL $THEN ...
$$plsql_compilation_parameter
 The name plsql_compilation_parameter is a PL/SQL compilation parameter (for example, PLSCOPE_SETTINGS).

The following SQL*Plus script uses the predefined inquiry directives $$PLSQL_LINE and $$PLSQL_UNIT as ordinary PLS_INTEGER and VARCHAR2 literals, respectively, to show how their values are assigned.

Demo

SQL>
SQL> CREATE OR REPLACE PROCEDURE p
  2  IS-- w  w w  .  ja v  a 2s  .  c o m
  3    i PLS_INTEGER;
  4  BEGIN
  5    DBMS_OUTPUT.PUT_LINE('Inside p');
  6    i := $$PLSQL_LINE;
  7    DBMS_OUTPUT.PUT_LINE('i = ' || i);
  8    DBMS_OUTPUT.PUT_LINE('$$PLSQL_LINE = ' || $$PLSQL_LINE);
  9    DBMS_OUTPUT.PUT_LINE('$$PLSQL_UNIT = ' || $$PLSQL_UNIT);
 10  END;
 11  /

Procedure created.

SQL>
SQL>
SQL> BEGIN
  2   p;
  3   DBMS_OUTPUT.PUT_LINE('Outside p');
  4   DBMS_OUTPUT.PUT_LINE('$$PLSQL_UNIT = ' || $$PLSQL_UNIT);
  5  END;
  6  /
Inside p
i = 6
$$PLSQL_LINE = 8
$$PLSQL_UNIT = P
Outside p
$$PLSQL_UNIT =

PL/SQL procedure successfully completed.

SQL>
SQL>

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