在jeecgboot中制作查询报表非常方便，可以在online报表配置中快速完成。

在数据库中可以看到对应的两张表存放这些配置，一张是onl_cgreport_head，存放查询表的头部信息。

另一张是明细表onl_cgreport_item，存放查询报表的字段信息。

在开发数据大屏时需要很多查询数据，可以先在online报表中配置查询SQL，通过报表查看需要的数据，然后用VBA通过数据库中的这两张表可以生成jeecgboot后端接口代码。

首先在MySQL 官网上下载 Excel 连接 MySQL 数据库的工具，连接为：
https://dev.mysql.com/downloads/windows/excel/

连接mysql的方法

Public Sub OpenConnection(Server As String, PORT As Long, DB As String, UID As String, PWD As String)
    Set conn = New ADODB.Connection
    conn.ConnectionString = "Driver={MySQL ODBC 8.0 Unicode Driver};Server=" & Server _
                            & ";Port=" & PORT & ";DB=" & DB & ";UID=" & UID & ";PWD=" & PWD & ";OPTION=3;"
    conn.Open
End Sub 

查询SQL数据并显示到listview的方法

Public Sub dataToListView(sql As String, lv As ListView)
    lv.ListItems.Clear
    lv.ColumnHeaders.Clear
    Dim i, j
    Dim rc As New ADODB.Recordset
    rc.Open sql, conn, adOpenStatic
    For i = 0 To rc.Fields.Count - 1
        lv.ColumnHeaders.Add , , rc.Fields(i).Name
    Next i
    rc.MoveFirst
    i = 1
    Do Until rc.EOF
        lv.ListItems.Add , , rc.Fields(0)
        For j = 1 To rc.Fields.Count - 1
            If Not IsNull(rc.Fields(j)) Then lv.ListItems(i).SubItems(j) = rc.Fields(j)
        Next j
        i = i + 1
        rc.MoveNext
    Loop
    rc.Close
    Set rc = Nothing
End Sub

将上面方法放到类模块中，就可以实例化对象来使用方法。

如连接数据库，将编码以"sql_"开头的的SQL报表显示到listview1中

msql.OpenMySQLConnection IP, PORT, DATABASE, USERNAME, PASSWORD
msql.dataToListView "select * from onl_cgreport_head where left(code,4)=""sql_""", ListView1

选择SQL报表，显示明细到listview2中。

Private Sub ListView1_ItemClick(ByVal Item As MSComctlLib.ListItem)
    msql.dataToListView "select * from onl_cgreport_item where cgrhead_id=""" & Item.Text & """", ListView2
End Sub

一键生成文件夹、java和xml文件

If ListView1.SelectedItem Is Nothing Then
Else
    folderPath = ThisWorkbook.Path & "\api"
    entity = Replace(ListView1.SelectedItem.SubItems(1), "sql_", "")
    desc = ListView1.SelectedItem.SubItems(2)
    cf.MakeFolder folderPath
    cf.MakeFolder folderPath & "\" & entity
    cf.MakeFolder folderPath & "\" & entity & "\controller"
    createController
    cf.MakeFolder folderPath & "\" & entity & "\entity"
    createEntity
    cf.MakeFolder folderPath & "\" & entity & "\mapper"
    cf.MakeFolder folderPath & "\" & entity & "\mapper\xml"
    createXML
    createMapper
    cf.MakeFolder folderPath & "\" & entity & "\service"
    createService
    cf.MakeFolder folderPath & "\" & entity & "\service\impl"
    createImpl
End If

其中生成实体类的代码

Dim cf As New CFileAction
With cf
    .Clear
    .WriteText "package org.jeecg.modules.demo.api." & entity & ".entity;" & vbCrLf
    .WriteText "import lombok.Data;" & vbCrLf
    .WriteText "@Data" & vbCrLf
    .WriteText "public class " & entity & " {" & vbCrLf
    For i = 1 To ListView2.ListItems.Count
        .WriteText "    private " & ListView2.ListItems(i).SubItems(5) & " " & ListView2.ListItems(i).SubItems(2) & ";" & vbCrLf
    Next i
    .WriteText "}" & vbCrLf
    WriteUTF8File .txt, folderPath & "\" & entity & "\entity\" & entity & ".java"
End With
Set cf = Nothing

生成java代码时需要的是没有BOM的UTF-8编码，一开始使用ADODB.Stream对象来保存java文件，IDEA打开后每个文件都要切换GBK再换回UTF-8编码才能正常使用。后来用以下api函数来保存java文件，默认bBOM为false，生成的代码可以直接运行使用。

Public Declare PtrSafe Function MultiByteToWideChar Lib "kernel32" ( _
ByVal CodePage As Long, _
ByVal dwFlags As Long, _
ByRef lpMultiByteStr As Any, _
ByVal cchMultiByte As Long, _
ByVal lpWideCharStr As Long, _
ByVal cchWideChar As Long) As Long

Public Declare PtrSafe Function WideCharToMultiByte Lib "kernel32" ( _
ByVal CodePage As Long, _
ByVal dwFlags As Long, _
ByVal lpWideCharStr As LongPtr, _
ByVal cchWideChar As Long, _
ByRef lpMultiByteStr As Any, _
ByVal cchMultiByte As Long, _
ByVal lpDefaultChar As String, _
ByVal lpUsedDefaultChar As Long) As Long

Public Const CP_UTF8 = 65001

' 将输入文本写进UTF8格式的文本文件
' 输入
' strInput：文本字符串
' strFile：保存的UTF8格式文件路径
' bBOM：True表示文件带"EFBBBF"头，False表示不
Public Sub WriteUTF8File(strInput As String, strFile As String, Optional bBOM As Boolean = False)
    Dim bByte As Byte
    Dim ReturnByte() As Byte
    Dim lngBufferSize As Long
    Dim lngResult As Long
    Dim TLen As Long
    ' 判断输入字符串是否为空
    If Len(strInput) = 0 Then Exit Sub
    'On Error GoTo errHandle
    ' 判断文件是否存在，如存在则删除
    If Dir(strFile) <> "" Then Kill strFile
    TLen = Len(strInput)
    lngBufferSize = TLen * 3 + 1
    ReDim ReturnByte(lngBufferSize - 1)
    lngResult = WideCharToMultiByte(CP_UTF8, 0, StrPtr(strInput), TLen, ReturnByte(0), lngBufferSize, vbNullString, 0)
    If lngResult Then
        lngResult = lngResult - 1
        ReDim Preserve ReturnByte(lngResult)
        Open strFile For Binary As #1
            If bBOM = True Then
                bByte = 239
                Put #1, , bByte
                bByte = 187
                Put #1, , bByte
                bByte = 191
                Put #1, , bByte
            End If
            Put #1, , ReturnByte
        Close #1
    End If
End Sub

api接口测试成功。