If you invoke sqlColumns the data type returned from the column changes depending on if you used the UNICODE or non-UNICODE driver. This is with the 8.04.01 driver.
Get Data All:
"TABLE_QUALIFIER", "TABLE_OWNER", "TABLE_NAME", "COLUMN_NAME", "DATA_TYPE", "TYPE_NAME", "PRECISION", "LENGTH", "SCALE", "RADIX", "NULLABLE", "REMARKS", "COLUMN_DEF", "SQL_DATA_TYPE", "SQL_DATETIME_SUB", "CHAR_OCTET_LENGTH", "ORDINAL_POSITION", "IS_NULLABLE", "DISPLAY_SIZE", "FIELD_TYPE", "AUTO_INCREMENT", "PHYSICAL NUMBER", "TABLE OID", "BASE TYPEID"
"TEST1", "public", "z", "c1", 1, "bpchar", 6, 6, <Null>, <Null>, 1, "", <Null>, 1, <Null>, 12, 1, <Null>, 6, 1042, 0, 1, 45819, 0
1 row fetched from 24 columns.
Get Data All:
"TABLE_QUALIFIER", "TABLE_OWNER", "TABLE_NAME", "COLUMN_NAME", "DATA_TYPE", "TYPE_NAME", "PRECISION", "LENGTH", "SCALE", "RADIX", "NULLABLE", "REMARKS", "COLUMN_DEF", "SQL_DATA_TYPE", "SQL_DATETIME_SUB", "CHAR_OCTET_LENGTH", "ORDINAL_POSITION", "IS_NULLABLE", "DISPLAY_SIZE", "FIELD_TYPE", "AUTO_INCREMENT", "PHYSICAL NUMBER", "TABLE OID", "BASE TYPEID"
"TEST1", "public", "z", "c1", -8, "bpchar", 6, 12, <Null>, <Null>, 1, "", <Null>, -8, <Null>, 12, 1, <Null>, 6, 1042, 0, 1, 45819, 0
1 row fetched from 24 columns.