Add support for adding relations on MySQL < 5 (#530)

Source/SPTableRelations.m

@@ -270,11 +270,25 @@ - (IBAction)addRelation:(id)sender
	}

	// Get all InnoDB tables in the current database
	// TODO: MySQL 4 compatibility
	SPMySQLResult *result = [connection queryString:[NSString stringWithFormat:@"SELECT table_name FROM information_schema.tables WHERE table_type = 'BASE TABLE' AND engine = 'InnoDB' AND table_schema = %@", [[tableDocumentInstance database] tickQuotedString]]];
	[result setDefaultRowReturnType:SPMySQLResultRowAsArray];
	for (NSArray *eachRow in result) {
		[refTablePopUpButton addItemWithTitle:[eachRow objectAtIndex:0]];
	if ([[tableDocumentInstance serverSupport] supportsInformationSchema]) {
		//MySQL 5.0+
		SPMySQLResult *result = [connection queryString:[NSString stringWithFormat:@"SELECT table_name FROM information_schema.tables WHERE table_type = 'BASE TABLE' AND engine = 'InnoDB' AND table_schema = %@", [[tableDocumentInstance database] tickQuotedString]]];
		[result setDefaultRowReturnType:SPMySQLResultRowAsArray];
		for (NSArray *eachRow in result) {
			[refTablePopUpButton addItemWithTitle:[eachRow objectAtIndex:0]];
		}
	}
	else {
		//this will work back to 3.23.0, innodb was added in 3.23.49
		SPMySQLResult *result = [connection queryString:[NSString stringWithFormat:@"SHOW TABLE STATUS FROM %@", [[tableDocumentInstance database] backtickQuotedString]]];
		[result setDefaultRowReturnType:SPMySQLResultRowAsArray];
		[result setReturnDataAsStrings:YES]; // some mysql versions would return NSData for string fields otherwise
		for (NSArray *eachRow in result) {
			// col[1] was named "Type" < 4.1, "Engine" afterwards
			if(![[[eachRow objectAtIndex:1] uppercaseString] isEqualToString:@"INNODB"]) continue;
			// col[0] is the table name
			[refTablePopUpButton addItemWithTitle:[eachRow objectAtIndex:0]];
		}
	}

	// Reset other fields