Sql VB.Net合并/更新查询不工作

我有两个sql数据库表klaar和klaarvb，我想用以下代码合并它们：

      Dim READER As SqlDataReader

    Try
        konneksie.Open()
        Dim query As String

        query = "MERGE blokkeklaar as target" & _
                "USING blokkeklaarVB AS source" & _
                "On target.Plaasblok = source.Plaasblok" & _
                "WHEN MATCHED THEN" & _
                "UPDATE SET klaarvb = source.klaarvb;"

        COMMAND = New SqlCommand(query, konneksie)
        READER = COMMAND.ExecuteReader
        MessageBox.Show("Inligting vanaf blokkeklaarVB  na blokkeklaar")

        konneksie.Close()



    Catch ex As Exception
        MessageBox.Show(ex.Message)
    Finally
    End Try

我收到一个错误“blokkeklaarVB附近的语法不正确”

在SQl Manager中运行该语句时，我得到了正确的结果：

 MERGE blokkeklaar as target
                USING blokkeklaarVB AS source
                On target.Plaasblok = source.Plaasblok
                WHEN MATCHED THEN
                UPDATE SET klaarvb = source.klaarvb;

我不知道我错过了什么

---

关于

当连接不同的行时，行继续之前的单词之间缺少空格

    query = "MERGE blokkeklaar as target " & _
            "USING blokkeklaarVB AS source " & _
            "On target.Plaasblok = source.Plaasblok " & _
            "WHEN MATCHED THEN " & _
            "UPDATE SET klaarvb = source.klaarvb;"

---

连接不同的行时，行继续之前的单词之间缺少空格

    query = "MERGE blokkeklaar as target " & _
            "USING blokkeklaarVB AS source " & _
            "On target.Plaasblok = source.Plaasblok " & _
            "WHEN MATCHED THEN " & _
            "UPDATE SET klaarvb = source.klaarvb;"

---

非常感谢。完全正确我正要回答我自己的问题。谢谢。完全正确我正要回答我自己的问题。