Add PL/pgSQL SQLSTATE and SQLERRM support which sets these values on

error.

Pavel Stehule

doc/src/sgml/plpgsql.sgml

@@ -1,5 +1,5 @@
 <!--
-$PostgreSQL: pgsql/doc/src/sgml/plpgsql.sgml,v 1.67 2005/04/19 03:55:43 momjian Exp $
+$PostgreSQL: pgsql/doc/src/sgml/plpgsql.sgml,v 1.68 2005/05/26 00:16:31 momjian Exp $
 -->
 
 <chapter id="plpgsql"> 
@@ -2007,12 +2007,13 @@ END LOOP;
     </indexterm>
 
     <para>
-     By default, any error occurring in a <application>PL/pgSQL</>
+     Any error occurring in <application>PL/pgSQL</> sets variables
-     function aborts execution of the function, and indeed of the
+     <varname>SQLSTATE</> and <varname>SQLERRM</>, and, by default,
-     surrounding transaction as well.  You can trap errors and recover
+     aborts execution of the function, and indeed of the surrounding
-     from them by using a <command>BEGIN</> block with an
+     transaction as well. You can trap errors and recover from them by
-     <literal>EXCEPTION</> clause.  The syntax is an extension of the
+     using a <command>BEGIN</> block with an <literal>EXCEPTION</>
-     normal syntax for a <command>BEGIN</> block:
+     clause. The syntax is an extension of the normal syntax for a
+     <command>BEGIN</> block:
 
 <synopsis>
 <optional> &lt;&lt;<replaceable>label</replaceable>&gt;&gt; </optional>

src/pl/plpgsql/src/gram.y

@@ -4,7 +4,7 @@
  *						  procedural language
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/pl/plpgsql/src/gram.y,v 1.69 2005/04/07 14:53:04 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/pl/plpgsql/src/gram.y,v 1.70 2005/05/26 00:16:31 momjian Exp $
  *
  *	  This software is copyrighted by Jan Wieck - Hamburg.
  *
@@ -80,6 +80,11 @@ static	void			 plpgsql_sql_error_callback(void *arg);
 			int  n_initvars;
 			int  *initvarnos;
 		}						declhdr;
+		struct 
+		{
+			int sqlstate_varno;
+			int sqlerrm_varno;
+		}						fict_vars;
 		List					*list;
 		PLpgSQL_type			*dtype;
 		PLpgSQL_datum			*scalar;	/* a VAR, RECFIELD, or TRIGARG */
@@ -96,6 +101,7 @@ static	void			 plpgsql_sql_error_callback(void *arg);
 		PLpgSQL_diag_item		*diagitem;
 }
 
+%type <fict_vars> fict_vars_sect
 %type <declhdr> decl_sect
 %type <varname> decl_varname
 %type <str>		decl_renname
@@ -244,19 +250,22 @@ opt_semi		:
 				| ';'
 				;
 
-pl_block		: decl_sect K_BEGIN lno proc_sect exception_sect K_END
+pl_block		: decl_sect fict_vars_sect K_BEGIN lno proc_sect exception_sect K_END
 					{
 						PLpgSQL_stmt_block *new;
 
 						new = palloc0(sizeof(PLpgSQL_stmt_block));
 
 						new->cmd_type	= PLPGSQL_STMT_BLOCK;
-						new->lineno		= $3;
+						new->lineno		= $4;
 						new->label		= $1.label;
 						new->n_initvars = $1.n_initvars;
 						new->initvarnos = $1.initvarnos;
-						new->body		= $4;
+						new->body		= $5;
-						new->exceptions	= $5;
+						new->exceptions	= $6;
+
+						new->sqlstate_varno = $2.sqlstate_varno;
+						new->sqlerrm_varno = $2.sqlerrm_varno;
 
 						plpgsql_ns_pop();
 
@@ -264,6 +273,19 @@ pl_block		: decl_sect K_BEGIN lno proc_sect exception_sect K_END
 					}
 				;
 
+fict_vars_sect	:
+					{
+						PLpgSQL_variable	*var;
+
+						plpgsql_ns_setlocal(false);
+						var = plpgsql_build_variable("sqlstate", 0,
+										 plpgsql_build_datatype(TEXTOID, -1), true);  
+						$$.sqlstate_varno = var->dno;
+						var = plpgsql_build_variable("sqlerrm", 0,
+										 plpgsql_build_datatype(TEXTOID, -1), true);  
+						$$.sqlerrm_varno = var->dno;
+						plpgsql_add_initdatums(NULL);
+					};
 
 decl_sect		: opt_label
 					{

src/pl/plpgsql/src/pl_exec.c

@@ -3,7 +3,7 @@
  *			  procedural language
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/pl/plpgsql/src/pl_exec.c,v 1.138 2005/05/06 17:24:55 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/pl/plpgsql/src/pl_exec.c,v 1.139 2005/05/26 00:16:31 momjian Exp $
  *
  *	  This software is copyrighted by Jan Wieck - Hamburg.
  *
@@ -180,6 +180,7 @@ static Datum exec_simple_cast_value(Datum value, Oid valtype,
 static void exec_init_tuple_store(PLpgSQL_execstate *estate);
 static bool compatible_tupdesc(TupleDesc td1, TupleDesc td2);
 static void exec_set_found(PLpgSQL_execstate *estate, bool state);
+static char *unpack_sql_state(int ssval);
 
 
 /* ----------
@@ -747,6 +748,20 @@ exec_stmt_block(PLpgSQL_execstate *estate, PLpgSQL_stmt_block *block)
 	int			i;
 	int			n;
 
+
+  	/* setup SQLSTATE and SQLERRM */
+  	PLpgSQL_var *var;
+  
+  	var = (PLpgSQL_var *) (estate->datums[block->sqlstate_varno]);
+  	var->isnull = false;
+  	var->freeval = true;
+  	var->value = DirectFunctionCall1(textin, CStringGetDatum("00000"));
+  
+  	var = (PLpgSQL_var *) (estate->datums[block->sqlerrm_varno]);
+   	var->isnull = false;
+  	var->freeval = true;
+  	var->value = DirectFunctionCall1(textin, CStringGetDatum("Sucessful completion"));
+
 	/*
 	 * First initialize all variables declared in this block
 	 */
@@ -855,6 +870,16 @@ exec_stmt_block(PLpgSQL_execstate *estate, PLpgSQL_stmt_block *block)
 			RollbackAndReleaseCurrentSubTransaction();
 			MemoryContextSwitchTo(oldcontext);
 			CurrentResourceOwner = oldowner;
+ 
+			/* set SQLSTATE and SQLERRM variables */
+		    
+			var = (PLpgSQL_var *) (estate->datums[block->sqlstate_varno]);
+			pfree((void *) (var->value));
+			var->value = DirectFunctionCall1(textin, CStringGetDatum(unpack_sql_state(edata->sqlerrcode)));
+  
+			var = (PLpgSQL_var *) (estate->datums[block->sqlerrm_varno]);
+			pfree((void *) (var->value));
+			var->value = DirectFunctionCall1(textin, CStringGetDatum(edata->message));
 
 			/*
 			 * If AtEOSubXact_SPI() popped any SPI context of the subxact,
@@ -919,6 +944,26 @@ exec_stmt_block(PLpgSQL_execstate *estate, PLpgSQL_stmt_block *block)
 	return PLPGSQL_RC_OK;
 }
 
+/* 
+ * unpack MAKE_SQLSTATE code 
+ * This code is copied from backend/utils/error/elog.c.
+ */
+static char *
+unpack_sql_state(int ssval)
+{
+	static 	char		tbuf[12];
+	int			i;
+
+	for (i = 0; i < 5; i++)
+	{
+		tbuf[i] = PGUNSIXBIT(ssval);
+ 		ssval >>= 6;
+ 	}
+ 	tbuf[i] = '\0';
+	return tbuf;
+}
+
+
 
 /* ----------
  * exec_stmts			Iterate over a list of statements

src/pl/plpgsql/src/plpgsql.h

@@ -3,7 +3,7 @@
  *			  procedural language
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/pl/plpgsql/src/plpgsql.h,v 1.58 2005/04/05 06:22:16 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/pl/plpgsql/src/plpgsql.h,v 1.59 2005/05/26 00:16:31 momjian Exp $
  *
  *	  This software is copyrighted by Jan Wieck - Hamburg.
  *
@@ -336,9 +336,11 @@ typedef struct
 	int			lineno;
 	char	   *label;
 	List	   *body;			/* List of statements */
-	List	   *exceptions;		/* List of WHEN clauses */
+	List	   *exceptions; 	/* List of WHEN clauses */
-	int			n_initvars;
+	int 		n_initvars;
-	int		   *initvarnos;
+	int 	   *initvarnos;
+	int 		sqlstate_varno;
+	int 		sqlerrm_varno;
 } PLpgSQL_stmt_block;
 
 

src/test/regress/expected/plpgsql.out

@@ -2380,3 +2380,29 @@ ERROR:  control reached end of function without RETURN
 CONTEXT:  PL/pgSQL function "missing_return_expr"
 drop function void_return_expr();
 drop function missing_return_expr();
+-- test SQLSTATE and SQLERRM
+create or replace function trap_exceptions() returns void as $_$
+begin
+   begin
+     raise exception 'first exception';
+   exception when others then
+     raise notice '% %', SQLSTATE, SQLERRM;
+   end;
+   raise notice '% %', SQLSTATE, SQLERRM;
+   begin
+     raise exception 'last exception';
+   exception when others then
+     raise notice '% %', SQLSTATE, SQLERRM;
+   end;
+   return;
+end; $_$ language plpgsql;
+select trap_exceptions();
+NOTICE:  P0001 first exception
+NOTICE:  00000 Sucessful completion
+NOTICE:  P0001 last exception
+ trap_exceptions 
+-----------------
+ 
+(1 row)
+
+drop function trap_exceptions();

src/test/regress/sql/plpgsql.sql

@@ -2018,3 +2018,23 @@ select missing_return_expr();
 
 drop function void_return_expr();
 drop function missing_return_expr();
+-- test SQLSTATE and SQLERRM
+create or replace function trap_exceptions() returns void as $_$
+begin
+   begin
+     raise exception 'first exception';
+   exception when others then
+     raise notice '% %', SQLSTATE, SQLERRM;
+   end;
+   raise notice '% %', SQLSTATE, SQLERRM;
+   begin
+     raise exception 'last exception';
+   exception when others then
+     raise notice '% %', SQLSTATE, SQLERRM;
+   end;
+   return;
+end; $_$ language plpgsql;
+
+select trap_exceptions();
+
+drop function trap_exceptions();