c#操作Access(上)

    技术2024-06-21  72

    看到上不断兄弟姐妹提问关于c#操作Access的问题,于是本人利用闲暇将c#操作Access的方法加以总结,主要解决的问题有:创建mdb创建table读取table内容查询table中的内容向table中插入数据删除table中的记录向table中插入照片读取table中的照片等。另:本人水平有限,不当之处还请斧正。废话少说,开始正题。

    文介绍C#访问操作Access数据库的基础知识,并提供一个相关的例程。C#的ADO.NET还不能通过编程方式创建全新的ACCESS(MDB)数据库,所以还只能使用ADOX这个来自COM的链接库来操作。主要知识点如下:using System.Data.OleDb;using System.Data;连接字符串:String connectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=product.mdb";建立连接:OleDbConnection connection = new OleDbConnection(connectionString);使用OleDbCommand类来执行Sql语句:OleDbCommand cmd = new OleDbCommand(sql, connection);connection.Open();cmd.ExecuteNonQuery();

    1.创建mdb库,例程如下: 需要注意的是:参数mdbPath是mdb的完整路径(不包含表的名称)。例如:D://test.mdb

    view plaincopy to clipboardprint?//创建mdb     public static bool CreateMDBDataBase(string mdbPath)    {        try       {            ADOX.CatalogClass cat = new ADOX.CatalogClass();            cat.Create("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + mdbPath + ";");            cat = null;            return true;        }        catch { return false; }    }         //创建mdb         public static bool CreateMDBDataBase(string mdbPath)        {            try            {                ADOX.CatalogClass cat = new ADOX.CatalogClass();                cat.Create("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + mdbPath + ";");                cat = null;                return true;            }            catch { return false; }        } 

    2.创建具体的表,例程如下:通常一个mdb的可以包含n个表。下面的程序主要是创建一个table。view plaincopy to clipboardprint?//新建mdb的表    //mdbHead是一个ArrayList,存储的是table表中的具体列名。    public static bool CreateMDBTable(string mdbPath,string tableName, ArrayList mdbHead)   {       try      {           ADOX.CatalogClass cat = new ADOX.CatalogClass();           string sAccessConnection               = @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + mdbPath;           ADODB.Connection cn = new ADODB.Connection();           cn.Open(sAccessConnection, null, null, -1);           cat.ActiveConnection = cn;             //新建一个表            ADOX.TableClass tbl = new ADOX.TableClass();           tbl.ParentCatalog = cat;           tbl.Name = tableName;             int size = mdbHead.Count;           for (int i = 0; i < size; i++)           {               //增加一个文本字段                ADOX.ColumnClass col2 = new ADOX.ColumnClass();               col2.ParentCatalog = cat;               col2.Name = mdbHead[i].ToString();//列的名称                col2.Properties["Jet OLEDB:Allow Zero Length"].Value = false;               tbl.Columns.Append(col2, ADOX.DataTypeEnum.adVarWChar, 500);           }           cat.Tables.Append(tbl);   //这句把表加入数据库(非常重要)            tbl = null;           cat = null;           cn.Close();           return true;       }       catch { return false; }   }          //新建mdb的表         //mdbHead是一个ArrayList,存储的是table表中的具体列名。         public static bool CreateMDBTable(string mdbPath,string tableName, ArrayList mdbHead)        {            try            {                ADOX.CatalogClass cat = new ADOX.CatalogClass();                string sAccessConnection                    = @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + mdbPath;                ADODB.Connection cn = new ADODB.Connection();                cn.Open(sAccessConnection, null, null, -1);                cat.ActiveConnection = cn;

                    //新建一个表                 ADOX.TableClass tbl = new ADOX.TableClass();                tbl.ParentCatalog = cat;                tbl.Name = tableName;

                    int size = mdbHead.Count;                for (int i = 0; i < size; i++)                {                    //增加一个文本字段                     ADOX.ColumnClass col2 = new ADOX.ColumnClass();                    col2.ParentCatalog = cat;                    col2.Name = mdbHead[i].ToString();//列的名称                     col2.Properties["Jet OLEDB:Allow Zero Length"].Value = false;                    tbl.Columns.Append(col2, ADOX.DataTypeEnum.adVarWChar, 500);                }                cat.Tables.Append(tbl);   //这句把表加入数据库(非常重要)                 tbl = null;                cat = null;                cn.Close();                return true;            }            catch { return false; }        }

    3.读取mdb内容(完全读取),例程如下:本例程返回的是一个DataTable,如需其他格式可以自行转换。view plaincopy to clipboardprint?// 读取mdb数据    public static DataTable ReadAllData(string tableName, string mdbPath,ref bool success)   {       DataTable dt = new DataTable();       try      {           DataRow dr;           //1、建立连接            string strConn               = @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + mdbPath + ";Jet OLEDB:Database Password=haoren";           OleDbConnection odcConnection = new OleDbConnection(strConn);           //2、打开连接            odcConnection.Open();           //建立SQL查询            OleDbCommand odCommand = odcConnection.CreateCommand();           //3、输入查询语句            odCommand.CommandText = "select * from " + tableName;           //建立读取            OleDbDataReader odrReader = odCommand.ExecuteReader();           //查询并显示数据            int size = odrReader.FieldCount;           for (int i = 0; i < size; i++)           {               DataColumn dc;               dc = new DataColumn(odrReader.GetName(i));               dt.Columns.Add(dc);           }           while (odrReader.Read())           {               dr = dt.NewRow();               for (int i = 0; i < size; i++)               {                   dr[odrReader.GetName(i)] = odrReader[odrReader.GetName(i)].ToString();               }               dt.Rows.Add(dr);           }           //关闭连接            odrReader.Close();           odcConnection.Close();           success = true;           return dt;       }       catch      {           success = false;           return dt;       }   }          // 读取mdb数据         public static DataTable ReadAllData(string tableName, string mdbPath,ref bool success)        {            DataTable dt = new DataTable();            try            {                DataRow dr;                //1、建立连接                 string strConn                    = @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + mdbPath + ";Jet OLEDB:Database Password=haoren";                OleDbConnection odcConnection = new OleDbConnection(strConn);                //2、打开连接                 odcConnection.Open();                //建立SQL查询                 OleDbCommand odCommand = odcConnection.CreateCommand();                //3、输入查询语句                 odCommand.CommandText = "select * from " + tableName;                //建立读取                 OleDbDataReader odrReader = odCommand.ExecuteReader();                //查询并显示数据                 int size = odrReader.FieldCount;                for (int i = 0; i < size; i++)                {                    DataColumn dc;                    dc = new DataColumn(odrReader.GetName(i));                    dt.Columns.Add(dc);                }                while (odrReader.Read())                {                    dr = dt.NewRow();                    for (int i = 0; i < size; i++)                    {                        dr[odrReader.GetName(i)] = odrReader[odrReader.GetName(i)].ToString();                    }                    dt.Rows.Add(dr);                }                //关闭连接                 odrReader.Close();                odcConnection.Close();                success = true;                return dt;            }            catch            {                success = false;                return dt;            }        }

    4.读取mdb内容(按列读取),例程如下:columns数组存储的是你要查询的列名称(必须确保mdb表中存在你要的列)

    view plaincopy to clipboardprint?// 读取mdb数据    public static DataTable ReadDataByColumns(string mdbPaht,string tableName, string[] columns, ref bool success)   {       DataTable dt = new DataTable();       try      {           DataRow dr;           //1、建立连接            string strConn               = @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + mdbPath + ";Jet OLEDB:Database Password=haoren";           OleDbConnection odcConnection = new OleDbConnection(strConn);           //2、打开连接            odcConnection.Open();           //建立SQL查询            OleDbCommand odCommand = odcConnection.CreateCommand();           //3、输入查询语句            string strColumn = "";           for (int i = 0; i < columns.Length; i++)           {               strColumn += columns[i].ToString() + ",";           }           strColumn = strColumn.TrimEnd(',');           odCommand.CommandText = "select "+strColumn+" from " + tableName;           //建立读取            OleDbDataReader odrReader = odCommand.ExecuteReader();           //查询并显示数据            int size = odrReader.FieldCount;           for (int i = 0; i < size; i++)           {               DataColumn dc;               dc = new DataColumn(odrReader.GetName(i));               dt.Columns.Add(dc);           }             while (odrReader.Read())           {               dr = dt.NewRow();               for (int i = 0; i < size; i++)               {                   dr[odrReader.GetName(i)] = odrReader[odrReader.GetName(i)].ToString();               }               dt.Rows.Add(dr);           }           //关闭连接            odrReader.Close();           odcConnection.Close();           success = true;           return dt;       }       catch      {           success = false;           return dt;       }   }          // 读取mdb数据         public static DataTable ReadDataByColumns(string mdbPaht,string tableName, string[] columns, ref bool success)        {            DataTable dt = new DataTable();            try            {                DataRow dr;                //1、建立连接                 string strConn                    = @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + mdbPath + ";Jet OLEDB:Database Password=haoren";                OleDbConnection odcConnection = new OleDbConnection(strConn);                //2、打开连接                 odcConnection.Open();                //建立SQL查询                 OleDbCommand odCommand = odcConnection.CreateCommand();                //3、输入查询语句                 string strColumn = "";                for (int i = 0; i < columns.Length; i++)                {                    strColumn += columns[i].ToString() + ",";                }                strColumn = strColumn.TrimEnd(',');                odCommand.CommandText = "select "+strColumn+" from " + tableName;                //建立读取                 OleDbDataReader odrReader = odCommand.ExecuteReader();                //查询并显示数据                 int size = odrReader.FieldCount;                for (int i = 0; i < size; i++)                {                    DataColumn dc;                    dc = new DataColumn(odrReader.GetName(i));                    dt.Columns.Add(dc);                }

                    while (odrReader.Read())                {                    dr = dt.NewRow();                    for (int i = 0; i < size; i++)                    {                        dr[odrReader.GetName(i)] = odrReader[odrReader.GetName(i)].ToString();                    }                    dt.Rows.Add(dr);                }                //关闭连接                 odrReader.Close();                odcConnection.Close();                success = true;                return dt;            }            catch            {                success = false;                return dt;            }        } 

    今天就简单写到这里,以后我会将内容补充完整。

    补充一句:转载的朋友请一定注明出处谢谢!半支烟阿杰 http://blog.csdn.net/gisfarmer/

    最新回复(0)