List 将每个项目与列表中的其余项目进行比较

我试图将每个表列与另一个表的列逐一进行比较

这是场景

我有三张这样的桌子

我得到了他们的信息，比如TableRow列表

TableRow(students,INT,10,id)
TableRow(students,VARCHAR,200,name)
TableRow(students,VARCHAR,100,address)

TableRow(department,INT,10,id)
TableRow(department,VARCHAR,100,department_name)

TableRow(teacher,INT,10,id)
TableRow(teacher,INT,10,suvject)

假设我想将每一行与其他表的剩余行进行比较，如下->

TableRow(students,INT,10,id) - TableRow(department,INT,10,id)
TableRow(students,INT,10,id) - TableRow(department,VARCHAR,100,department_name)
TableRow(students,INT,10,id) - TableRow(teacher,INT,10,id)
TableRow(students,INT,10,id) - TableRow(teacher,INT,10,suvject)

TableRow(students,VARCHAR,200,name) - TableRow(department,INT,10,id)
TableRow(students,VARCHAR,200,name) - TableRow(department,VARCHAR,100,department_name)
TableRow(students,VARCHAR,200,name) - TableRow(teacher,INT,10,id)
TableRow(students,VARCHAR,200,name) - TableRow(teacher,INT,10,suvject)

TableRow(students,VARCHAR,100,address) - TableRow(department,INT,10,id)
TableRow(students,VARCHAR,100,address) - TableRow(department,VARCHAR,100,department_name)
TableRow(students,VARCHAR,100,address) - TableRow(teacher,INT,10,id)
TableRow(students,VARCHAR,100,address) - TableRow(teacher,INT,10,suvject)

TableRow(department,INT,10,id) - TableRow(teacher,INT,10,id)
TableRow(department,INT,10,id) - TableRow(teacher,INT,10,subject)

TableRow(department,VARCHAR,100,department_name) - TableRow(teacher,INT,10,id)
TableRow(department,VARCHAR,100,department_name) - TableRow(teacher,INT,10,subject)

因此，我将每个表列与上面的其他表列进行比较

我正在使用这样的代码来比较它，这是可行的，但是有没有更好的方法来实现这一点呢？一个很好的功能性写作方式

 val stack = mutable.Stack[TableRow]().pushAll(tableRows)
    val arrayList = new util.ArrayList[JoinInfo]()

    while (stack.nonEmpty) {
      val currentRow = stack.pop()
      stack.foreach(targetRow => {
        if (!(targetRow.tableName.equals(currentRow.tableName) && targetRow.schema.equals(currentRow.schema))) { //not comparing with current table's column with its other column.
          arrayList.add(compareColumns(currentRow, targetRow))
        }
      })
    }

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我会这样写：

(tableRows zip tableRows).filter {
  case(currentRow, targetRow) => !(targetRow.tableName.equals(currentRow.tableName) && targetRow.schema.equals(currentRow.schema))
}

---

因此，除了使用zip函数避免手动写入双循环外，基本相同。

另外，请阅读。试着在代码审查时问这个问题。whi@user，我不明白你的逻辑，它会如何比较currentRow和TargetRow的每个条目？@user我想你没有正确理解我的问题。它不是关于删除重复，而是将列表中的每个项目与剩余的条件进行比较，因为它不应该考虑比较当前行的表和模式名称是否与另一行匹配。@用户嗯，不是这样的，请看我的第二个块，在那里我解释了实际预期发生的事情。那你就明白了是的。以下是链接：。另外，我认为您需要类似于，在循环中使用

yield

，因为我不确定如何将其用于我的代码。你能详细说明一下吗？