SELECT 
    CONCAT('C','~') AS "1", FFIITMN,
    CASE WHEN FFIITMN IN (SELECT FGDITMN FROM S2151BDW.PWRDTA.FGDPRPIP WHERE FGDCMPN = '  1' THEN '1' ELSE '0' END) AS "16"
FROM 
    S2151BDW.PWRDTA.FFIITMAP --Item master file
    JOIN S2151BDW.PWRDTA.FFJITMBP ON FFJITMN = FFIITMN AND FFJCMPN = FFICMPN --Item balance file
    JOIN S2151BDW.PWRDTA.FFBCLSAP ON FFBCLSN = FFJCLSN AND FFBCMPN = FFICMPN --Item class file

WHERE 
    FFICMPN = '  1' 
AND
    FFIITMN = '    365725'

返回错误：
比较运算符IN无效.. SQLCODE= -115，SQLSTATE =42601，DRIVER=3.69.56
是否可以在select中使用case语句来检查项目编号是否在另一个表中？