ado.net数据库访问问题，求解答！

Question

本帖最后由 li_xi_quan 于 2011-10-24 09:40:59 编辑

Answer 1

private void previousPage_LinkClicked(object sender, LinkLabelLinkClickedEventArgs e)
        {
            //上一页
            if (pageCurrent == 0)//如果当前页数为0，则提示操作无效，停止运行，防止异常发生
            {
                MessageBox.Show("没有数据显示，操作无效！");
            }
            else
            {
                pageCurrent--;
                if (pageCurrent <= 0)//当前页号
                {
                    MessageBox.Show("已经是第一页，请点击“下一页”查看！");
                    pageCurrent++;
                    return;
                }
                else
                {
                    nCurrent = pageSize * (pageCurrent - 1);
                }
                LoadData();
                if (this.currentPages.Value > 1)
                {
                    --this.currentPages.Value;
                }
            }
        }        private void nextPage_LinkClicked(object sender, LinkLabelLinkClickedEventArgs e)
        {
            //下一页
            if (pageCurrent == 0)//如果当前页数为0，则提示操作无效，停止运行，防止异常发生
            {
                MessageBox.Show("没有数据显示，操作无效！");
            }
            else
            {
                pageCurrent++;
                if (pageCurrent > pageCount)//当前页号>页数
                {
                    MessageBox.Show("已经是最后一页，请点击“上一页”查看！");
                    pageCurrent--;
                    return;
                }
                else
                {
                    nCurrent = pageSize * (pageCurrent - 1);
                }
                LoadData();
                if (this.currentPages.Value < this.currentPages.Maximum)
                {
                    ++this.currentPages.Value;
                }
            }
        }        private void firstPage_LinkClicked(object sender, LinkLabelLinkClickedEventArgs e)
        {
            //第一页
            if (pageCurrent == 0)//如果当前页数为0，则提示操作无效，停止运行，防止异常发生
            {
                MessageBox.Show("没有数据显示，操作无效！");
            }
            else
            {
                pageCurrent = 1;    //当前页数从1开始
                nCurrent = 0; //当前记录数从0开始
                LoadData();
                this.currentPages.Value = 1;
            }
        }        private void lastPage_LinkClicked(object sender, LinkLabelLinkClickedEventArgs e)
        {
            //最后页
            pageCurrent = pageCount;
            nCurrent = pageSize * (pageCurrent - 1);
            if (pageCurrent == 0)//如果当前页数为0，则提示操作无效，停止运行，防止异常发生
            {
                MessageBox.Show("没有数据显示，操作无效！");
            }
            else
            {
                LoadData();
                this.currentPages.Value = Convert.ToInt32(this.totalPages.Text);
            }
        }        private void currentPages_ValueChanged(object sender, EventArgs e)
        {
            //转到指定页
            int page = Convert.ToInt32(this.currentPages.Value);
            if (page > page1 && page <= pageCount)
            {
                int number = page - page1;
                if (pageCurrent < pageCount)
                {
                    pageCurrent = pageCurrent + number;
                    if (pageCurrent == pageCount)
                    {
                        nCurrent = pageSize * (pageCurrent - 1);                    }
                    else
                    {
                        nCurrent = pageSize * (pageCurrent - 1);
                    }
                    LoadData();
                }
            }            if (0 < page && page < page1)
            {
                int number = page1 - page;
                if (pageCurrent > 0)
                {
                    pageCurrent = pageCurrent - number;
                    if (pageCurrent == 1)
                    {
                        nCurrent = pageSize * (pageCurrent - 1);
                    }
                    else
                    {
                        nCurrent = pageSize * (pageCurrent - 1);
                    }
                    LoadData();
                }
            }
        }        private void saveAdd_Click(object sender, EventArgs e)//添加记录
        {
            if (dataGridView1.Rows.Count == 0)//如果dataGridView1的行数为0，说明其中尚未有数据(显示数据)，则提示并且中断刷新操作
            {
                MessageBox.Show("没有记录添加，不需要保存添加！");
            }
            else
            {
                if (MessageBox.Show("确定要添加记录到MySQL数据库吗？", "警告！", MessageBoxButtons.OKCancel, MessageBoxIcon.Warning) == DialogResult.OK)
                {
                    conn = new MySqlConnection();     // 创建mysql连接对象 
                    MyConnectionString = "server = 192.168.0.22; uid = users; pwd = 85836262; charset = utf8 ;database = " + databaseName1;
                    conn.ConnectionString = MyConnectionString;       // 配置连接 
                    conn.Open(); // 打开连接
                    myadp = new MySqlDataAdapter("select * from " + tableName, conn);
                    objCommandBuilder = new MySqlCommandBuilder(myadp);
                    myadp.Update(dtTemp, tableName); 
                    dtTemp.AcceptChanges();
                    MessageBox.Show("数据已成功添加到MySQL数据库！");
                    conn.Close();
                }
            }
        }        private DataTable GetTableNames1(string sql)//GetTableNames1()方法，用于获取所有数据库名
        {
            MySqlConnection conn = null;
            MySqlCommand command = null;
            MySqlDataReader reader = null;
            DataTable getName = new DataTable();            //DataTable table = GetTableNames1("show databases");//调用GetTableNames1()获取所有数据库名
            //databaseName2 = table.Rows[0][0].ToString();            conn = new MySqlConnection("Server=192.168.0.22;uid=users;pwd=85836262;charset = utf8 ;Database=xscj");////获取数据库名时，先要在某个数据库中建立一个登录验证的表
            command = conn.CreateCommand();
            command.CommandText = sql;
            conn.Open();
            reader = command.ExecuteReader();
            getName.Load(reader);
            conn.Close();
            command = null;
            reader.Close();
            return getName;
        }        private DataTable GetTableNames2(string sql)//GetTableNames2()方法，用于获取某个数据库中所有表名
        {
            MySqlConnection conn = null;
            MySqlCommand command = null;
            MySqlDataReader reader = null;
            DataTable getName = new DataTable();
            conn = new MySqlConnection("Server=192.168.0.22;uid=users;pwd=85836262;charset = utf8 ;Database=" + databaseName1);
            command = conn.CreateCommand();
            command.CommandText = sql;
            conn.Open();
            reader = command.ExecuteReader();
            getName.Load(reader);
            conn.Close();
            command = null;
            reader.Close();
            return getName;
        }

Answer 2

 private void getTableName_Click(object sender, EventArgs e)//获取MySQL服务器中某个数据库的所有表名，并且把所有表名在checkedListBox1中显示
        {
            if (databaseName1 == null)
            {
                MessageBox.Show("你还没有获取或者选中一个数据库名！");
            }
            else
            {
                checkedListBox1.Items.Clear();//当用户再次单击获取数据集按钮时，防止在checkedListBox1中重复显示，先清除之前checkedListBox1中的内容
                DataTable table = GetTableNames2("show tables");//调用GetTableNames2()获取某个数据库中所有表名
                for (int i = 0; i < table.Rows.Count; i++)
                {
                    checkedListBox1.Items.Add(table.Rows[i][0].ToString());
                }
            }
        }        private void Form1_FormClosed(object sender, FormClosedEventArgs e)
        {
            Application.Exit();
        }        private void checkedListBox1_ItemCheck(object sender, ItemCheckEventArgs e)//控制checkedListBox1只能单选，不能复选
        {
            if (this.checkedListBox1.CheckedItems.Count > 0)
            {
                for (int i = 0; i < this.checkedListBox1.Items.Count; i++)
                {
                    if (i != e.Index)
                    {
                        this.checkedListBox1.SetItemCheckState(i, System.Windows.Forms.CheckState.Unchecked);
                    }
                }
            }
        }        private void checkedListBox1_SelectedIndexChanged(object sender, EventArgs e)
        {
            tableName = checkedListBox1.SelectedItem.ToString();
        }        private void getDataBaseName_Click(object sender, EventArgs e)//获取MySQL服务器中所有的数据库名，并且把所有的数据库名在checkedListBox2中显示
        {
            checkedListBox2.Items.Clear();
            DataTable table = GetTableNames1("show databases");//调用GetTableNames1()获取所有数据库名
            for (int i = 0; i < table.Rows.Count; i++)
            {
                if (table.Rows[i][0].ToString() != "information_schema" && table.Rows[i][0].ToString() != "mysql"
                    && table.Rows[i][0].ToString() != "performance_schema" && table.Rows[i][0].ToString() != "test"
                    && table.Rows[i][0].ToString() != "work")
                {
                    checkedListBox2.Items.Add(table.Rows[i][0].ToString());
                }
                else
                    continue;
            }
        }        private void checkedListBox2_ItemCheck(object sender, ItemCheckEventArgs e)//控制checkedListBox2只能单选，不能复选
        {
            if (this.checkedListBox2.CheckedItems.Count > 0)
            {
                for (int i = 0; i < this.checkedListBox2.Items.Count; i++)
                {
                    if (i != e.Index)
                    {
                        this.checkedListBox2.SetItemCheckState(i, System.Windows.Forms.CheckState.Unchecked);
                    }
                }
            }
        }        private void checkedListBox2_SelectedIndexChanged(object sender, EventArgs e)
        {
            databaseName1 = checkedListBox2.SelectedItem.ToString();
        }
    }
}以上是程序的完整代码

Answer 3

问题解决了，改用ODBC访问数据库，就没有问题了，呵呵。