pg中，用SELECT判断一个字段值是否是另一种段值的子集

SELECT a."VAJ47" AS "RIS_Date",
    a."BCK01B" AS "RIS_DeptCode",
    a."BBY01" AS "RIS_ItemCode",
    a."VAJ25" AS "RIS_SL",
    a."VAJ36" AS "RIS_JE",--a表是科室收入表
    b.*,--是医疗项目与收费项目对照表
        (
        SELECT 
            "HD_Code"
        FROM 
            "public"."Hosp_Dept"  
        WHERE 
            a."BCK01B"::TEXT=ANY (string_to_array("Hosp_Dept"."HIS_Department",','))
        )         AS "项目科室代码", --科室成本中的标准科室
        (
        SELECT 
            "HD_Name"
        FROM 
            "public"."Hosp_Dept"  
        WHERE 
            a."BCK01B"::TEXT=ANY (string_to_array("Hosp_Dept"."HIS_Department",','))
        )         AS "项目科室名称"    
   FROM "test"."Remote_IncomeStatement" a
     LEFT JOIN "PayItems_Dict" b ON (((a."BBY01")::VARCHAR = (b."PID_PayCode")::text))