机房收费系统之组合查询
在没有开始敲组合查询的时候就已经了解了很多天了，查了很多资料，又看了很多人的文章，终于自己敲出来了，下面以 学生基本信息维护 为例
字段名为Combo1、Combo2、Combo3
操作符为Combo4、Combo5、Combo6
要查询的内容Text1、Text2、Text3
组合关系为Combo7、Combo8
Private Sub Command2_Click()
'单行查询
If Combo1.Text = "" Or Combo4.Text = "" Or Text1.Text = "" Then
MsgBox "请保证查询信息完整！", vbOKOnly + vbExclamation, "提示"
Exit Sub
End If
txtSQL = "select * from student_Info where " & Trim(field(Combo1.Text)) & Trim(Combo4.Text) & "'" & Trim(Text1.Text) & "'"
Set mrc = ExecuteSQL(txtSQL, MsgText)
If mrc.EOF = True Then
MsgBox "该条件的数据不存在！", vbOKOnly + vbExclamation, "提示"
Call Cancel
Combo1.SetFocus
Exit Sub
Else
Call Add
End If
'两行查询
If Not Combo7.Text = "" Then
If Combo1.Text = "" Or Combo2.Text = "" Or Combo4.Text = "" Or Combo5.Text = "" Or Text1.Text = "" Or Text2.Text = "" Then
MsgBox "请保证查询信息完整！", vbOKOnly + vbExclamation, "提示"
Exit Sub
Else
Select Case Combo7
Case "与"
a = "and"
Case "或"
a = "or"
End Select
txtSQL = txtSQL & a & " " & Trim(field(Combo2.Text)) & Trim(Combo5.Text) & "'" & Trim(Text2.Text) & "'"
Set mrc = ExecuteSQL(txtSQL, MsgText)
If mrc.EOF = True Then
MsgBox "该条件的数据不存在！", vbOKOnly + vbExclamation, "提示"
Call Cancel
Combo1.SetFocus
Exit Sub
Else
Call Add
End If
End If
End If
'三行查询
If Not Combo8.Text = "" Then
If Combo1.Text = "" Or Combo2.Text = "" Or Combo3.Text = "" Or Combo4.Text = "" Or Combo5.Text = "" Or Combo6.Text = "" Or Text1.Text = "" Or Text2.Text = "" Or Text3.Text = "" Then
MsgBox "请保证查询信息完整！", vbOKOnly + vbExclamation, "提示"
Exit Sub
Else
Select Case Combo8
Case "与"
b = "and"
Case "或"
b = "or"
End Select
txtSQL = txtSQL & b & " " & Trim(field(Combo3.Text)) & Trim(Combo6.Text) & "'" & Trim(Text3.Text) & "'"
Set mrc = ExecuteSQL(txtSQL, MsgText)
MsgBox MsgText
If mrc.EOF = True Then
MsgBox "该条件的数据不存在！", vbOKOnly + vbExclamation, "提示"
Call Cancel
Combo1.SetFocus
Exit Sub
Else
Call Add
End If
End If
End If
End Sub
Public Function Cancel()
Combo1.Text = ""
Combo2.Text = ""
Combo3.Text = ""
Combo4.Text = ""
Combo5.Text = ""
Combo6.Text = ""
Combo7.Text = ""
Combo8.Text = ""
Text1.Text = ""
Text2.Text = ""
Text3.Text = ""
With MSHFlexGrid1
.Rows = 2
.CellAlignment = 4
.TextMatrix(0, 0) = ""
.TextMatrix(0, 1) = ""
.TextMatrix(0, 2) = ""
.TextMatrix(0, 3) = ""
.TextMatrix(0, 4) = ""
.TextMatrix(0, 5) = ""
.TextMatrix(0, 6) = ""
.TextMatrix(0, 7) = ""
.TextMatrix(0, 8) = ""
.TextMatrix(0, 9) = ""
.TextMatrix(0, 10) = ""
.TextMatrix(0, 11) = ""
.TextMatrix(0, 12) = ""
.TextMatrix(1, 0) = ""
.TextMatrix(1, 1) = ""
.TextMatrix(1, 2) = ""
.TextMatrix(1, 3) = ""
.TextMatrix(1, 4) = ""
.TextMatrix(1, 5) = ""
.TextMatrix(1, 6) = ""
.TextMatrix(1, 7) = ""
.TextMatrix(1, 8) = ""
.TextMatrix(1, 9) = ""
.TextMatrix(1, 10) = ""
.TextMatrix(1, 11) = ""
.TextMatrix(1, 12) = ""
End With
End Function
Add是我定义的一个添加过程，同样也是为了能够方便反复调用
Public Function Add()
With MSHFlexGrid1
.Rows = 1
.CellAlignment = 4
.TextMatrix(0, 0) = "学号"
.TextMatrix(0, 1) = "姓名"
.TextMatrix(0, 2) = "卡号"
.TextMatrix(0, 3) = "金额"
.TextMatrix(0, 4) = "系别"
.TextMatrix(0, 5) = "年级"
.TextMatrix(0, 6) = "班级"
.TextMatrix(0, 7) = "性别"
.TextMatrix(0, 8) = "状态"
.TextMatrix(0, 9) = "备注"
.TextMatrix(0, 10) = "类型"
.TextMatrix(0, 11) = "日期"
.TextMatrix(0, 12) = "时间"
Do While Not mrc.EOF
.Rows = .Rows + 1
.TextMatrix(.Rows - 1, 0) = mrc.Fields(1)
.TextMatrix(.Rows - 1, 1) = mrc.Fields(2)
.TextMatrix(.Rows - 1, 2) = mrc.Fields(0)
.TextMatrix(.Rows - 1, 3) = mrc.Fields(7)
.TextMatrix(.Rows - 1, 4) = mrc.Fields(4)
.TextMatrix(.Rows - 1, 5) = mrc.Fields(5)
.TextMatrix(.Rows - 1, 6) = mrc.Fields(6)
.TextMatrix(.Rows - 1, 7) = mrc.Fields(3)
.TextMatrix(.Rows - 1, 8) = mrc.Fields(10)
.TextMatrix(.Rows - 1, 9) = mrc.Fields(8)
.TextMatrix(.Rows - 1, 10) = mrc.Fields(14)
.TextMatrix(.Rows - 1, 11) = Format(mrc.Fields(12), "yyyy-mm-dd")
.TextMatrix(.Rows - 1, 12) = Format(mrc.Fields(13), "hh:mm:ss")
mrc.MoveNext
Loop
End With
mrc.Close
End Function
field 是为了把汉字转换成数据库中的字段名，为了方便查询数据库而定义的一个过程。
Public Function field(combox As String) As String
Select Case combox
Case "卡号"
field = "cardno"
Case "姓名"
field = "studentName"
Case "学号"
field = "studentNo"
Case "金额"
field = "cash"
Case "系别"
field = "department"
Case "年级"
field = "grade"
Case "班级"
field = "class"
Case "性别"
field = "sex"
Case "状态"
field = "status"
Case "备注"
field = "Ischeck"
Case "类型"
field = "type"
Case "日期"
field = "date"
Case "时间"
field = "time"
End Select
End Function
我的整体思路是： 如果只进行单行查询，则第二三行不可用。
如果进行两行组合查询，则第三行不可用。
只有当进行三行查询时，三行均可使用。
所以还有几行代码
Private Sub Combo7_Click()
If Combo7.Text <> Trim("") Then
Combo2.Enabled = True
Combo5.Enabled = True
Combo8.Enabled = True
Text2.Enabled = True
End If
End Sub
Private Sub Combo8_Click()
If Combo8.Text <> Trim("") Then
Combo3.Enabled = True
Combo6.Enabled = True
Text3.Enabled = True
End If
End Sub
Private Sub Form_Load()
If Combo7.Text = Trim("") Then
Combo2.Enabled = False
Combo3.Enabled = False
Combo5.Enabled = False
Combo6.Enabled = False
Combo8.Enabled = False
Text2.Enabled = False
Text3.Enabled = False
End If
If Combo8.Text = Trim("") Then
Combo3.Enabled = False
Combo6.Enabled = False
Text3.Enabled = False
End If
其他几个组合查询的窗体就都大同小异了，也不是很难吧