vb sqlite 使用 litex

Private Declare Function LoadLibrary Lib "kernel32" Alias "LoadLibraryA" (ByVal lpLibFileName As String) As Long
Dim oDB As Object
Public dbPath As String '存储 数据库路径
Private Sub Class_Initialize()
    Dim lb As Long
    lb = LoadLibrary(App.Path & "\sqlite3.dll")
    Set oDB = CreateObject("LiteX.LiteConnection")
End Sub
 
Private Sub openDB()
    oDB.Open (dbPath)
End Sub
 
Public Function Insert(ByVal tableName As String, ByRef arr() As String) As String '插入 数据库的操作，返回受影响的行数,tableName为表名,arr为插入的字段名和值的二维数组
    Dim str_Fields As String, str_Values As String, strSql As String
    strSql = "insert into " & tableName
    For I = 0 To UBound(arr)
        str_Fields = str_Fields & "'" & arr(I, 0) & "',"
        str_Values = str_Values & "'" & Trim(Replace(arr(I, 1), "'", "''")) & "',"
    Next I
    str_Fields = Mid(str_Fields, 1, Len(str_Fields) - 1)
    str_Values = Mid(str_Values, 1, Len(str_Values) - 1)
    strSql = strSql & "(" & str_Fields & ") values (" & str_Values & ")"
    openDB (dbPath)
    oDB.Execute (strSql)
    Insert = oDB.changes
    oDB.Close
End Function
 
Public Function Query(ByVal tableName As String, Optional ByVal Fields As String = "", Optional Condition As String = "", Optional ByVal Exp As String = "") As String() '查询数据。返回结果数组，tableName 表名，fields是你要查询哪些字段,condition是查询条件也就是where， 为其它条件。例如order by ，group by，limit，offset等
    Dim arr() As String, sqlStr As String, K As Integer
    Dim odbRS As Object
    Set odbRS = CreateObject("LiteX.LiteStatement")
    Fields = IIf(Fields = "", "*", Fields)
    odbRS.ActiveConnection = oDB
    sqlStr = "select " & Fields & " from " & tableName & IIf(Condition = "", "", " where " & Condition & " ") & IIf(Exp = "", "", " " & Exp & " ")
    Debug.Print sqlStr
    openDB (dbPath)
    d = odbRS.prepare(sqlStr)
    If odbRS.Rows.Count = 0 Then
        Query = arr
    Else
        ReDim arr(odbRS.Rows.Count - 1, odbRS.Columns.Count - 1)
        For Each Row In odbRS.Rows
            For I = 0 To odbRS.Columns.Count - 1
                arr(K, I) = Row(I)
            Next I
            K = K + 1
        Next
    End If
    Query = arr
    odbRS.Close
    oDB.Close
End Function
 
Public Function Modify(ByVal tableName As String, ByRef arr() As String, Optional Condition As String = "") As Integer'实现数据修改功能。tableName表名，arr和insert方法一样的。Condition 为条件，返回受影响的行数
    Dim str_ As String, strSql As String
    strSql = "update " & tableName & " set "
    For I = 0 To UBound(arr)
        str_ = str_ & "`" & Trim(arr(I, 0)) & "`='" & Trim(Replace(arr(I, 1), "'", "''")) & "',"
    Next I
    strSql = strSql & Mid(str_, 1, Len(str_) - 1) & IIf(Condition = "", "", " where " & Condition & " ")
    Debug.Print strSql
    openDB (dbPath)
    oDB.Execute (strSql)
    Modify = oDB.changes
    oDB.Close
End Function
 
Public Function Delete(ByVal tableName As String, Optional ByVal Condition As String = "") As Integer'删除数据的功能。tableName为表名，condition为条件，返回受影响的行数。
    Dim str_ As String
    strSql = "delete from " & tableName & IIf(Condition = "", "", " where " & Condition)
    Debug.Print strSql
    openDB (dbPath)
    oDB.Execute (strSql)
    Delete = oDB.changes
    oDB.Close
End Function

查询

 Dim sqlite As New ClsSqlite
    sqlite.dbPath = 这里搞上你的数据库的路径
    arr = sqlite.Query("这里是表名", "", "`username`='小松'")
'将返回查询结果数组

添加

Private Function makeArr() As String()'本函数为制作一个要插入数据的数组。
    Dim arr() As String
    ReDim arr(2, 1)
    arr(0, 0) = "name" '这个是字段名
    arr(0, 1) = txtName.Text  '这个是字段值，下同
    arr(1, 0) = "oldname"
    arr(1, 1) = txtOldname.Text
    arr(2, 0) = "sex"
    arr(2, 1) = cmbSex.Text
    makeArr = arr
End Function
Private Sub cmdAdd_Click()
Dim pSqlite As New ClsSqlite
arr = makeArr  '这里调用makeArr得到要插入的数据的数组
pSqlite.Insert("populations", arr) '执行插入
End Sub

3、修改

修改和添加记录基本上差不多。也需要makeArr，唯一不同的是一个调用类里面的insert方法，一个调用类里面的modify方法，还有就是既然你要修改数据，需要指定条件，要修改哪个ID的数据。

pSqlite.Modify("populations", arr, "`uid`='" & Uid & "'") 'uid就是指定要修改uid为UID的这一条数据。

4、删除

删除最简单。提供一个表名，和一个条件即可。