如何根据数据库列中的值用数据填充 datagridview

Question

假设我有一个如下的数据库表“USAGE”：

MACHINE     WEEK        HOURS       PIECES
A           2018-12     1           2
B           2018-12     3           4
A           2018-13     12          1
B           2018-13     2           5
A           2018-15     6           6
B           2018-15     2           2
C           2018-16     2           1
D           2018-17     4           22
B           2018-17     3           9
A           2018-18     1           8
E           2018-18     4           4
D           2018-13     2           4

我想在datagridview中显示数据如下：

MACHINE     2018-12     2018-13     2018-14     2018-15     2018-16     2018-17     2018-18
A           1H 2P       12H 1P                  6H 6P                               1H 8P
B           3H 4P       2H 5P                   2H 2P                   3H 9P
C                                                           2H 1P
D                       2H 4P                                           4H 22P
E                                                                                   4H 4P

在视觉 foxpro 中，这非常简单。

this.edType      = 1
this.ehCols      = 20
this.ehStartval  = date()+ 7

这在标题中创建了 20 个不同周的列。然后使用如下命令完成：

this.ehKeyFld    = "iif(usage.hours > 0 and usage.pieces > 0,STR(usage.hours,4) + 'H ' + STR(usage.pieces,3)+'P','')"

现在我想做同样的事情，但我喜欢在 datagridview 中显示数据。

如果我这样做：

select machine, iif(week='2018-12',str(hours,4) + 'H' + str(pieces,3) + 'P','') as '2018-12', IIF(week='2018-13',str(hours,4) + 'H' + str(pieces,3) + 'P','') as '2018-13', IIF(week='2018-14',str(hours,4) + 'H' + str(pieces,3) + 'P','') as '2018-14', IIF(week='2018-15',str(hours,4) + 'H' + str(pieces,3) + 'P','') as '2018-15', IIF(week='2018-16',str(hours,4) + 'H' + str(pieces,3) + 'P','') as '2018-16', IIF(week='2018-17',str(hours,4) + 'H' + str(pieces,3) + 'P','') as '2018-17', IIF(week='2018-18',str(hours,4) + 'H' + str(pieces,3) + 'P','') as '2018-18' from GCCTEST.dbo.usage

我得到以下输出：

machine 2018-12 2018-13 2018-14 2018-15 2018-16 2018-17 2018-18
A       1H  2P                      
B       3H  4P                      
A               12H  1P                 
B               2H  5P                  
A                               6H  6P          
B                               2H  2P          
C                                       2H  1P      
D                                               4H 22P  
B                                               3H  9P  
A                                                       1H  8P
E                                                       4H  4P
D               2H  4P                  

我正在寻找一个 SQL 中的命令，它可以按照我想要的方式填充 datagridview，即每台机器的一行数据都在正确的列中。

Answer 1

我接受 VFP 让事情变得更容易。但是，说到 datagridview，我会假设您的意思是 C#，这也可以在 C# 中以多种方式完成。使用 SQL，您还可以使用“PIVOT”。即：

DECLARE @table TABLE([MACHINE] VARCHAR(1), [WEEK] VARCHAR(7), [HOURS] INT, [PIECES] INT);

INSERT INTO @table(MACHINE, WEEK, HOURS, PIECES)
VALUES('A', '2018-12', 1, 2),
    ('B', '2018-12', 3, 4),
    ('A', '2018-13', 12, 1),
    ('B', '2018-13', 2, 5),
    ('A', '2018-15', 6, 6),
    ('B', '2018-15', 2, 2),
    ('C', '2018-16', 2, 1),
    ('D', '2018-17', 4, 22),
    ('B', '2018-17', 3, 9),
    ('A', '2018-18', 1, 8),
    ('E', '2018-18', 4, 4),
    ('D', '2018-13', 2, 4);

SELECT *
FROM(
    SELECT MACHINE, WEEK, STR(HOURS, 4)+'H'+STR(PIECES, 3)+'P' AS data
    FROM @table
    ) AS source
PIVOT(
     MAX(data)
     FOR WEEK IN([2018-12], [2018-13], [2018-14], [2018-15], [2018-16], [2018-17], [2018-18])
     ) AS mypivot;

但是，您不希望在 SQL 中对所有这些列进行硬编码。检查“动态 PIVOT”。以下是 Northwind 数据的示例：

DECLARE @COUNTRY NVARCHAR(MAX) = '' , @cTotal NVARCHAR(MAX) = ''

SELECT  @COUNTRY = @COUNTRY + COALESCE(QUOTENAME(Country) + ', ', '')
FROM    Customers
WHERE   EXISTS ( SELECT *
                 FROM   [Orders] AS [o]
                 WHERE  o.[CustomerID] = Customers.[CustomerID] )
GROUP BY Country;

SET @COUNTRY = LEFT(@COUNTRY, LEN(@COUNTRY) - 1);

SELECT  @cTotal = @cTotal + COALESCE('Coalesce('+QUOTENAME(Country) + ',0) +', '')
FROM    Customers
WHERE   EXISTS ( SELECT *
                 FROM   [Orders] AS [o]
                 WHERE  o.[CustomerID] = Customers.[CustomerID] )
GROUP BY Country;

SET @cTotal = LEFT(@cTotal, LEN(@cTotal) - 1);

DECLARE @SQL NVARCHAR(MAX);

SET @SQL = 'SELECT * , ' + @cTotal + ' AS TOTAL FROM 
    (
        SELECT  oe.EmployeeID, oe.LastName, oe.ShipCountry AS CO,
                OD.Quantity * OD.UnitPrice AS QU
        FROM    (
                  SELECT  EmployeeID, LastName, ShipCountry
                  FROM    (
                            SELECT DISTINCT
                                    ShipCountry
                            FROM    Orders
                          ) o ,
                          Employees
                ) oe
        LEFT JOIN Orders O ON O.EmployeeID = oe.EmployeeID AND
                              [oe].[ShipCountry] = [O].[ShipCountry]
        LEFT JOIN [Order Details] OD ON OD.OrderID = O.OrderID 
    ) AS T
    PIVOT(SUM(QU) FOR CO IN (' + @COUNTRY + ')) AS PVT
    ORDER BY 1';

EXEC(@SQL); 

Answer 2

我的解决方案： 我在 tblMachines 中有一个包含机器描述的数据库，在 tblUsage 中有一个包含机器使用情况的数据库。 在我的 windows 窗体上，我有一个 datagridview Dgv_4 和一个 Combobox1

' Separate class to do the sql command
Public SQL As New SQLControl
Private Dgv_4Query As String = $"m.id,m.listorder,m.prio,m.machine as 'Machine',m.weekuren as 'Hour/wk', week, STR(u.HOURS, len(u.HOURS))+'h_'+STR(u.PIECES, len(u.PIECES))+'p' as data FROM {GV.DB}tblMachines m "
Private Dgv_4Join As String = $"LEFT JOIN {GV.DB}tblUsage u on m.machine = u.machine "
Private Dgv_4Pivot As String = ""
Private EmptyQueryStringDgv_4 As String = ""
Private TotNumWeeks As Integer = 15

Private Sub DataGridViewForm_Load(sender As Object, e As EventArgs) Handles MyBase.Load
    MdiParent = Main
    ' Create headers for datagridview with dates and weeknumbers starting with current week
    Dim WeekNumber As Integer = DatePart(DateInterval.WeekOfYear, Date.Now, FirstDayOfWeek.Monday, FirstWeekOfYear.System)
    ' First part of the pivot command
    Dim PivotString As String = $"PIVOT (MAX(data) FOR week IN("
    Dim endline As String = ","
    ' Middle part of the pivot command
    For i As Integer = 0 To TotNumWeeks
        If i = TotNumWeeks Then
            ' Last part of the pivot command
            endline = ")) as mypivot"
        End If
        PivotString = PivotString + $"[{Date.Today.Year}-{WeekNumber + i}]{endline}"
    Next
    Dgv_4Pivot = PivotString
    EmptyQueryStringDgv_4 = $"SELECT * FROM (SELECT {Dgv_4Query}{Dgv_4Join}) as source {Dgv_4Pivot} order by prio"
    LoadDataGridView1()
    ' Load combobox with current week
    ComboBox1.Items.Clear()
    ComboBox1.Text = $"{Date.Today.Year}-{WeekNumber}"
End Sub

Public Sub LoadDataGridView1(Optional ByVal QueryString As String = "", Optional ByVal Parameter As String = "")
    Dim dgvclass As New DataGridViewClass()
    Dim dname As DataGridView = Dgv_4
    Dim SelectRow As Integer = 0
    If QueryString = "" Then
        ' Default query
        QueryString = EmptyQueryStringDgv_4
    End If
    ' Use the sql command to request the data
    dgvclass.FillDataGridView(QueryString, Parameter, "Normal") = dname
    ' Hide column(s)
    dname.Columns(0).Visible = False
    dname.Columns(1).Visible = False
    ResizeGrid.ResizeGrid(dname, dname.Width)
End Sub

这将显示并加载从当前周开始的数据网格视图，并且您可以使用组合框选择不同的周：

Private Sub ComboBox_Drop(sender As Object, e As EventArgs) Handles ComboBox1.DropDown
    Dim ac As ComboBox = DirectCast(sender, ComboBox)
    If Me.ActiveControl Is ComboBox1 Then
        ComboBox1.Items.Clear()
        ' Fill combobox with a range of weeks to chose from
        For i As Integer = -1 To 1 Step 1
            For j As Integer = 1 To 52
                Dim num As String = j.ToString
                If Len(num) < 2 Then
                    num = $"0{num}"
                End If
                ComboBox1.Items.Add(Date.Today.Year + i & "-" & num)
            Next
        Next
    End If
End Sub

Private Sub ComboBox_SelectedIndexChanged(sender As Object, e As EventArgs) Handles ComboBox1.SelectedIndexChanged
    ' Create headers for datagridview with dates and weeknumbers
    Dim result As String = ComboBox1.SelectedItem
    Dim PivotString As String = $"PIVOT (MAX(data) FOR week IN("
    Dim endline As String = ","
    Dim weekadd As Integer = 0
    For i As Integer = 0 To TotNumWeeks
        If i = TotNumWeeks Then
            ' Close string
            endline = ")) as mypivot"
        Else
            ' Check year limits
            If (Convert.ToInt32(Strings.Right(result, 2)) + i) > 52 Then
                ' Change year and week
                weekadd = 0
                result = $"{Convert.ToInt32(Strings.Left(result, 4)) + 1.ToString}-01"
            End If
        End If
        PivotString = PivotString + $"[{Strings.Left(result, 4)}-{(Convert.ToInt32(Strings.Right(result, 2)) + weekadd).ToString("D2")}]{endline}"
        weekadd = weekadd + 1
    Next
    Dgv_4Pivot = PivotString
    ' Run query without pivot, seems to prevent insert columns on the right
    LoadDataGridView1($"SELECT {Dgv_4Query}{Dgv_4Join}")
    ' Run query with pivot to fill datagridview with new weeks
    LoadDataGridView1($"SELECT * FROM (SELECT {Dgv_4Query}{Dgv_4Join}) as source {Dgv_4Pivot} order by prio", "")
End Sub

输出示例：https://imgur.com/a/DTtloNz

Answer 3

我也发现在 SQL 中做起来更困难，而且 .Net 缺乏 VFP 的活力 你仍然可以通过自己的一些自定义数据透视来解决这个问题。在 VFP 中，枢轴通常称为交叉表。实际上，它是关于汇总数据，然后分发到列，其中一列值（这里是机器）被转置到列。在您的示例中，数据已经汇总，实际上不需要使用 MS SQL 的数据透视表。恕我直言，可以获取该数据并在数据表中本地创建交叉表，因为您只有大约 20-25 列（周）并且最多可能有 1000 台机器。这是采样代码（代码是使用 Telerik 代码转换器从 C# 转换而来的 - 注意：我昨天使用 MS SQL 服务器基础查询只是为了模拟您的数据将来自 MS SQL）：

Private Sub Main()
    Dim sql As String = "DECLARE @table TABLE([MACHINE] VARCHAR(1), [WEEK] VARCHAR(7), [HOURS] INT, [PIECES] INT);

INSERT INTO @table(MACHINE, WEEK, HOURS, PIECES)
VALUES('A', '2018-12', 1, 2),
    ('B', '2018-12', 3, 4),
    ('A', '2018-13', 12, 1),
    ('B', '2018-13', 2, 5),
    ('A', '2018-15', 6, 6),
    ('B', '2018-15', 2, 2),
    ('C', '2018-16', 2, 1),
    ('D', '2018-17', 4, 22),
    ('B', '2018-17', 3, 9),
    ('A', '2018-18', 1, 8),
    ('E', '2018-18', 4, 4),
    ('D', '2018-13', 2, 4);

    SELECT MACHINE, WEEK, HOURS, PIECES FROM @table"
    Dim tbl As DataTable = New DataTable()
    Using con = New SqlConnection("server=.\SQLExpress;Trusted_Connection=yes")
        con.Open()
        tbl.Load(New SqlCommand(sql, con).ExecuteReader())
        con.Close()
    End Using

    Dim weeks = 20
    Dim weekStart = 12
    Dim year = 2018
    Dim result As DataTable = New DataTable()
    result.Columns.Add("Machine", GetType(String))
    For i As Integer = 0 To weeks - 1
        Dim week = $"{year}-{i + weekStart}"
        result.Columns.Add(week, GetType(String))
    Next

    Dim lst = tbl.AsEnumerable()
    Dim machines = lst.[Select](Function(l) l.Field(Of String)("Machine")).Distinct().OrderBy(Function(l) l)
    For Each machine As String In machines
        Dim row = result.NewRow()
        row("Machine") = machine
        For i As Integer = 0 To weeks - 1
            Dim week = $"{year}-{i + weekStart}"
            Dim weekValue = lst.SingleOrDefault(Function(t) t.Field(Of String)("WEEK") = week AndAlso t.Field(Of String)("Machine") = machine)
            row(week) = If(weekValue Is Nothing, "", $"{CInt(weekValue("Hours"))}H {CInt(weekValue("Pieces"))}P")
        Next

        result.Rows.Add(row)
    Next

    Dim f As Form = New Form()
    f.Controls.Add(New DataGridView With {.Dock = DockStyle.Fill, .DataSource = result})
    f.Show()
End Sub