I am having problems using the union operator on two tables. Could
somebody point out my mistake. Below is the SQL code.

SELECT CAST LrgAddrData
FROM LargeAddress
WHERE WPVBSQ < 20
UNION ALL
SELECT CAST (SmllAddrData AS CHAR)
FROM SmallAddress
WHERE WPVBSQ < 20

Flamerobin shows the following error code :

*** IBPP::Exception inside Statement::Prepare ***

IBPP said : isc_dsql_prepare failed.

SQL Message : -104
Invalid token

Engine Code : 335544569
Engine Message :
Dynamic SQL Error
SQL error code = -104
Invalid command
Data type unknown


The tables look as follows :

Table : SmallAddress
SMLLADDRIDSQ INTEGER Not Null
WPVBSQ INTEGER Not Null
SMLLADDRDATA INTEGER Not Null
SMLLADDRTYP SMALLINT Not Null DEFAULT 1

Table : LargeAddress
LRGADDRIDSQ INTEGER Not Null
WPVBSQ INTEGER Not Null
LRGADDRDATA VARCHAR(100) Not Null
LRGADDRTYP SMALLINT Not Null DEFAULT 1