mysql - 带条件的 CASE 语句

Question

我的表中有两个字段 cust_shipmentdate_awb 和 comp_shipdate_awb。我正在尝试编写一个 CASE 语句，该语句应检查 cust_shipmentdate_awb 和 comp_shipdate_awb 两个字段是否为空或为空。如果两者都为 Null，则将结果显示为“待处理”。如果任何一个字段不为空，则它应显示为“已完成”，并且如果输入两个字段也应显示为“已完成”。我已经尝试过下面的 CASE 语句。但当输入两个字段数据时，它显示待定。

    CASE    
When cust_shipmentdate_awb Is Null Or cust_shipmentdate_awb = '' Then 'Pending'   
Else 'Completed' End AS shipment_status

Answer 1

使用子查询。

SELECT CASE WHEN shipment_date Is Null Or shipment_date = '' 
            THEN 'Pending' 
            Else 'Completed' 
        End AS shipment_status
FROM (
    SELECT CASE 
            When commercial_logi_freight.cust_shipmentdate_awb Is Null Or 
commercial_logi_freight.cust_shipmentdate_awb = '' 
            Then commercial_logi_freight.comp_shipdate_awb
            Else commercial_logi_freight.cust_shipmentdate_awb 
        End AS shipment_date
    FROM ...) AS x