Found out is a non qualified column is a column in uplevel subquery table like this:
take ma_parkey for example: ma_parkey is not a physical column
SELECT c_mandant
, CASE WHEN EXISTS (SELECT 1
FROM CDS_H_GRUPPE GRP1
WHERE GRP1.c_mandant = c_mandant
AND GRP1.parkey1 = ma_parkey)
THEN 1
ELSE NULL
END MA_ME
FROM (SELECT c_mandant
, CASE WHEN funktionscode = 'U'
THEN parkey1
ELSE parkey2
END MA_PARKEY
FROM
CDS_H_GRUPPE
)
COLLATE -
Static variable in class gudusoft.gsqlparser.nodes.TExpression
sql server, Is a clause that can be applied to a database definition or a column definition
to define the collation, or to a character string expression to apply a collation cast.