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。
sqlite3 litex 版请下载此附件: 附操作数据库的类模块代码以及使用方法。 类模块代码【添加一个类,比如我们取名为ClsSqlite】 将以下代码粘贴到类中: |
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