Fixed CORE-3073 - Foreign key cascade with SET DEFAULT uses the defau…

…lt value of the moment of the FK creation.
FirebirdSQL · Jan 20, 2017 · 7bb6ceb · 7bb6ceb
1 parent 7539585
commit 7bb6ceb
Showing 1 changed file with 51 additions and 77 deletions.
diff --git a/src/dsql/DdlNodes.epp b/src/dsql/DdlNodes.epp
@@ -6868,104 +6868,76 @@ void RelationNode::defineSetDefaultTrigger(DsqlCompilerScratch* dsqlScratch,
 	Constraint::BlrWriter& blrWriter = constraint.blrWritersHolder.add();
 	blrWriter.init(dsqlScratch);
 
-	generateUnnamedTriggerBeginning(constraint, onUpdate, blrWriter);
+	blrWriter.appendUChar(blr_begin);
 
-	const int BLOB_BUFFER_SIZE = 4096;	// to read in blr blob for default values
-	UCHAR defaultVal[BLOB_BUFFER_SIZE];
+	USHORT index = 0;
 
 	for (ObjectsArray<MetaName>::const_iterator column(constraint.columns.begin());
 		 column != constraint.columns.end();
-		 ++column)
+		 ++column, index += 2)
 	{
-		blrWriter.appendUChar(blr_assignment);
+		// If the FK table's column is NOT NULL without DEFAULT, we want to avoid the engine throwing a constraint
+		// violation on our trigger's variable, so we declare two variables, one with blr_domain_type_of (don't use
+		// DEFAULT and null flag) and another blr_domain_full with DEFAULT and null flag. We swallow the error when
+		// transfering the value from the second to the first variable.
 
-		// ASF: This is wrong way to do the thing. See CORE-3073.
-
-		// Here stuff the default value as blr_literal .... or blr_null
-		// if this column does not have an applicable default.
-		// The default is determined in many cases:
-		// (1) the info. for the column is in memory. (This is because
-		// the column is being created in this ddl statement).
-		// (1-a) the table has a column level default. We get this by
-		// searching the dsql parse tree.
-		// (1-b) the table does not have a column level default, but
-		// has a domain default. We get the domain name from the dsql
-		// parse tree and call METD_get_domain_default to read the
-		// default from the system tables.
-		// (2) The default-info for this column is not in memory (This is
-		// because this is an alter table ddl statement). The table
-		// already exists; therefore we get the column and/or domain
-		// default value from the system tables by calling:
-		// METD_get_col_default().
-
-		bool foundDefault = false;
-		bool searchForDefault = true;
-
-		// Search the parse tree to find the column
-
-		for (NestConst<Clause>* ptr = clauses.begin(); ptr != clauses.end(); ++ptr)
-		{
-			if ((*ptr)->type != Clause::TYPE_ADD_COLUMN)
-				continue;
+		blrWriter.appendUChar(blr_dcl_variable);
+		blrWriter.appendUShort(index);
 
-			AddColumnClause* clause = static_cast<AddColumnClause*>(ptr->getObject());
+		blrWriter.appendUChar(blr_column_name);
+		blrWriter.appendUChar(blr_domain_type_of);
+		blrWriter.appendNullString(0, name.c_str());
+		blrWriter.appendNullString(0, column->c_str());
 
-			if (*column != clause->field->fld_name)
-				continue;
+		blrWriter.appendUChar(blr_dcl_variable);
+		blrWriter.appendUShort(index + 1);
 
-			// Now we have the right column in the parse tree. case (1) above
+		blrWriter.appendUChar(blr_column_name);
+		blrWriter.appendUChar(blr_domain_full);
+		blrWriter.appendNullString(0, name.c_str());
+		blrWriter.appendNullString(0, column->c_str());
 
-			if (clause->defaultValue)
-			{
-				// case (1-a) above: There is a column level default
+		blrWriter.appendUChar(blr_assignment);
+		blrWriter.appendUChar(blr_null);
+		blrWriter.appendUChar(blr_variable);
+		blrWriter.appendUShort(index);
 
-				dsqlScratch->getBlrData().clear();
-				dsqlScratch->getDebugData().clear();
+		blrWriter.appendUChar(blr_block);	// 1
 
-				GEN_expr(dsqlScratch, clause->defaultValue->value);
+		blrWriter.appendUChar(blr_begin);	// 2
 
-				foundDefault = true;
-				searchForDefault = false;
+		blrWriter.appendUChar(blr_init_variable);
+		blrWriter.appendUShort(index + 1);
 
-				// Move the blr to the constraint blrWriter.
-				blrWriter.getBlrData().join(dsqlScratch->getBlrData());
-			}
-			else
-			{
-				if (!clause->field->typeOfName.hasData())
-					break;
+		blrWriter.appendUChar(blr_assignment);
+		blrWriter.appendUChar(blr_variable);
+		blrWriter.appendUShort(index + 1);
+		blrWriter.appendUChar(blr_variable);
+		blrWriter.appendUShort(index);
 
-				// case: (1-b): Domain name is available. Column level default
-				// is not declared. So get the domain default.
-				const USHORT defaultLen = METD_get_domain_default(dsqlScratch->getTransaction(),
-					clause->field->typeOfName, &foundDefault, defaultVal, sizeof(defaultVal));
+		blrWriter.appendUChar(blr_end);		// 2
 
-				searchForDefault = false;
+		blrWriter.appendUChar(blr_error_handler);
+		blrWriter.appendUShort(1);
+		blrWriter.appendUChar(blr_default_code);
+		blrWriter.appendUChar(blr_begin);	// 3
+		blrWriter.appendUChar(blr_end);		// 3
 
-				if (foundDefault)
-					stuffDefaultBlr(ByteChunk(defaultVal, defaultLen), blrWriter);
-				else
-				{
-					// Neither column level nor domain level default exists.
-					blrWriter.appendUChar(blr_null);
-				}
-			}
+		blrWriter.appendUChar(blr_end);		// 1
+	}
 
-			break;
-		}
+	generateUnnamedTriggerBeginning(constraint, onUpdate, blrWriter);
 
-		if (searchForDefault)
-		{
-			// case 2: See if the column/domain has already been created.
+	index = 0;
 
-			const USHORT defaultLen = METD_get_col_default(dsqlScratch->getTransaction(),
-				name.c_str(), column->c_str(), &foundDefault, defaultVal, sizeof(defaultVal));
+	for (ObjectsArray<MetaName>::const_iterator column(constraint.columns.begin());
+		 column != constraint.columns.end();
+		 ++column, index += 2)
+	{
+		blrWriter.appendUChar(blr_assignment);
 
-			if (foundDefault)
-				stuffDefaultBlr(ByteChunk(defaultVal, defaultLen), blrWriter);
-			else
-				blrWriter.appendUChar(blr_null);
-		}
+		blrWriter.appendUChar(blr_variable);
+		blrWriter.appendUShort(index);
 
 		// The context for the foreign key relation.
 		blrWriter.appendUChar(blr_field);
@@ -6978,6 +6950,8 @@ void RelationNode::defineSetDefaultTrigger(DsqlCompilerScratch* dsqlScratch,
 	if (onUpdate)
 		blrWriter.appendUCharRepeated(blr_end, 3);
 
+	blrWriter.appendUChar(blr_end);
+
 	blrWriter.appendUChar(blr_eoc);	// end of the blr
 
 	TriggerDefinition& trigger = constraint.triggers.add();