执行SQL时出现错误
不明确的列名“Chem_Num”
我该怎么办？
我在代码中尝试了此方法，但仍然不确定我做错了什么

SELECT 
    Chem_Num, Chem_Retail_Name, 
    Carried_Num as "Item Carry", 
    Tech_LName as "Driver",
    Job_Num, Used_Qty AS "Used on Job", 
    (Carried_Outbound - Carried_Return) AS "Gone from Truck" 
FROM
    PEPS.CHEMICAL 
JOIN 
    PEPS.CARRIED ON CHEMICAL.Chem_Num = CARRIED.Chem_Num
JOIN 
    PEPS.ASSIGNMENT ON CARRIED.Assign_Num = ASSIGNMENT.Assign_Num
JOIN 
    PEPS.TECHNICIAN ON ASSIGNMENT.Tech_Num = TECHNICIAN.Tech_Num
JOIN 
    PEPS.USED ON CHEMICAL.Chem_Num = USED.Chem_Num
WHERE
    Chem_Num IN (101, 103, 107) 
ORDER BY 
    Chem_Num ASC, Carried_Num ASC;