Sqlite.Swift不明确的列名Swift

我的代码如下：

let assetTag = Expression<String>("asset_tag")


let query2 = mdm.select(mdm[assetTag],os, mac, lastReported)
                .filter(mdm[assetTag] != "ipad" && location == facility)
                .order(mdm[assetTag])
                .join(mdm, on: ewp[assetTag] == mdm[assetTag])



            let results2 = try! db.prepare(query2)

let db = try Connection("\(path)/db.sqlite3")

        try db.run(ewp.create { t in
            t.column(assetTag)
            t.column(location)
            t.column(deviceStatus)

        })

        try db.run(mdm.create { t in
            t.column(assetTag)
            t.column(os)
            t.column(mac)
            t.column(lastReported)

        })

    }

---

出于某种原因，mdm[assetTag]仍然认为该列不明确，但只有一列是这样的。

找到了答案。我加入了mdm表本身。我需要将连接更改为：

.join（ewp，on:ewp[assetTag]==mdm[assetTag]）