Db2 Developer-C 11.1

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-- aggregate over scalar func
SELECT MAX(c)
FROM (SELECT 1 AS c, 2 AS d FROM sysibmadm.env_inst_info UNION ALL
      SELECT 2 AS c,-1 AS d FROM sysibmadm.env_inst_info
    )


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2


SELECT MAX(c)
FROM (SELECT 1 AS c, 2 AS d FROM sysibmadm.env_inst_info UNION ALL
      SELECT 2 AS c,-1 AS d FROM sysibmadm.env_inst_info
    )
GROUP BY ()


1


2


SELECT MAX(MAX(c))
FROM (SELECT 1 AS c, 2 AS d FROM sysibmadm.env_inst_info UNION ALL
      SELECT 2 AS c,-1 AS d FROM sysibmadm.env_inst_info
    )
[IBM][CLI Driver][DB2/LINUXX8664] SQL0112N  The operand of the column function "MAX" includes a column function, a scalar fullselect, or a subquery.  SQLSTATE=42607 SQLCODE=-112

-- scalar func
SELECT MAX(c,d)
FROM (SELECT 1 AS c, 2 AS d FROM sysibmadm.env_inst_info UNION ALL
      SELECT 2 AS c,-1 AS d FROM sysibmadm.env_inst_info
    )


1


2

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