Access/VBA/Excel-两个表联合查询左连接-11

2017-12-15 本文已影响6人 Data_Python_VBA

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系统：Windows 7
软件：Excel 2010 / Access 2010

这个系列开展一个新的篇章，重点关注Access数据库

主体框架：以Excel作为操作界面，Access作为数据库

今天讲讲如何将数据库中满足要求的数据拿出来

涉及知识：ADO，SQL：left join

Part 1：目标

成绩表

1.png

学生信息表

2.png

运行过程

1.gif

获取学号为1101学生在不同年级的语文成绩，输出信息包括：姓名，学号，性别，年级，语文成绩
最终想要获得的信息来自于两个工作表，所以需要连接查询
逻辑过程

连接数据库
根据需求确定SQL语句
执行SQL语句，得到recordset
将recordset写入工作表（字段名+所有记录即列名+每一行）
断开与数据库的连接

SQL语句

"Select " & opFilds & " from " & "(" & tbls & ")" & " where (" & searchC & ")"
opFilds = "姓名," & tblNote & ".学号,性别,年级,语文成绩"
searchC = tblNote & ".学号=1101"
tbls = tblNote & " left join " & tblName & " on " & tblNote & ".学号=" & tblName & ".学号"

Part 2：代码

Sub test()
    Dim cnn As New ADODB.Connection '连接
    Dim rs As New ADODB.Recordset
    Dim SQL As String
    Dim tblName
    Dim dbAddr
    
    dbAddr = ThisWorkbook.Path & "\学生信息.accdb"
    tblName = "学生信息表"
    tblNote = "成绩表"
    
    '连接数据库
    With cnn
        .Provider = "Microsoft.ACE.OLEDB.12.0"
        .Open "Data Source=" & dbAddr
    End With
    
    opFilds = "姓名," & tblNote & ".学号,性别,年级,语文成绩"
    searchC = tblNote & ".学号=1101"
    
    tbls = tblNote & " left join " & tblName _
    & " on " & tblNote & ".学号=" & tblName & ".学号"
    
    SQL = "Select " & opFilds & " from " & "(" & tbls & ")" & " where (" & searchC & ")"
    
    Set rs = cnn.Execute(SQL)

    Dim sht
    Dim fildNum
    
    Set sht = ThisWorkbook.Worksheets("示例")
    sht.Cells.ClearContents
    
    fildNum = rs.Fields.Count
    For j = 0 To fildNum - 1 Step 1
        fildName = rs.Fields(j).Name
        sht.Cells(1, j + 1) = fildName
    Next j
    
    sht.Cells(2, 1).CopyFromRecordset rs
    
    cnn.Close
    Set rs = Nothing
    Set cnn = Nothing

End Sub

代码截图