WaP网站模块,长沙百度推广公司电话,wordpress自定义作者连接,重要新闻头条[求助]如何仅在字段provider_order中删除NULL值,在我的情况下,表使用JOIN表和UNION这是我的数据库模式和我的SQL查询为了清楚地描述这里我附上图片最佳答案 您不能仅删除行中的该字段.但是,只需使用WHERE子句过滤掉具有空值的记录,就可以摆脱整行.SELECTm.provider_id,m.provid…[求助]如何仅在字段provider_order中删除NULL值,在我的情况下,表使用JOIN表和UNION这是我的数据库模式和我的SQL查询为了清楚地描述这里我附上图片最佳答案 您不能仅删除行中的该字段.但是,只需使用WHERE子句过滤掉具有空值的记录,就可以摆脱整行.SELECTm.provider_id,m.provider_name,p.purchase_order_code,NULL AS purchase_order_sample_code,p.provider_id AS provider_orderFROM mst_provider AS mLEFT JOIN trx_purchase_order AS pON (m.provider_id p.provider_id)WHERE p.provider_id ! NULLUNIONSELECTm.provider_id,m.provider_name,p.purchase_order_code,NULL AS purchase_order_sample_code,p.provider_id AS provider_orderFROM mst_provider AS mRIGHT JOIN trx_purchase_order AS pON (m.provider_id p.provider_id)UNIONSELECTm.provider_id,m.provider_name,NULL,s.purchase_order_sample_code,s.provider_idFROM mst_provider AS mRIGHT JOIN trx_purchase_order_sample AS sON (s.provider_id m.provider_id)
