Access数据库操作

建立表和字段,注意!是表,不是数据库,数据库你可要自己先建立好(空的就可以了)!!!        /// <summary>
        /// 打开数据库,建立新的表和字段
        /// </summary>
        /// <param name="spath">数据库全路径</param>
        /// <param name="dataname">表名</param>
        /// <param name="items">字段数组</param>
        private void newdatatable(string spath, string dataname, string[] items)
        {
            try
            {
                //连接到一个数据库
                string strCon = " Provider = Microsoft.Jet.OLEDB.4.0 ; Data Source = " + spath;
                OleDbConnection myConn = new OleDbConnection(strCon);
                myConn.Open();
                string strnew = " CREATE TABLE " + dataname + "( "
                    + items[0] + " TEXT(50) CONSTRAINT PK_tblCustomers PRIMARY KEY , ";
                for (int i = 1; i < items.Length - 1; i++)
                {
                    strnew += items[i] + " TEXT(50) , ";
                }
                strnew += items[items.Length - 1] + " TEXT(50) )";
          
                OleDbCommand myCommand = new OleDbCommand(strnew, myConn);
                myCommand.ExecuteNonQuery();
                myConn.Close();
            }
            catch (Exception ed)
            {
                MessageBox.Show("新建表错误信息： " + ed.ToString(), "错误！", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
        }
      删除数据库中的表/// <summary>
        /// 删除数据库中的表
        /// </summary>
        /// <param name="spath">数据库全名</param>
        /// <param name="dataname">表名</param>
        private void deletetable(string spath, string dataname)
        {
            try
            {
                //连接到一个数据库
                string strCon = " Provider = Microsoft.Jet.OLEDB.4.0 ; Data Source = " + spath;
                OleDbConnection myConn = new OleDbConnection(strCon);
                myConn.Open();
                string strnew = " DROP TABLE " + dataname;
                OleDbCommand myCommand = new OleDbCommand(strnew, myConn);
                myCommand.ExecuteNonQuery();
                myConn.Close();
            }
            catch (Exception ed)
            {
                //MessageBox.Show("删除表错误信息： " + ed.ToString(), "错误！", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
        }
      读入所有记录,如果要把dataset中的数据显示出来,把datagirdview的数据源绑定到dataset.tables[dataname]就ok了  /// <summary>
        /// 打开指定的access数据库,读入所有记录,填充到DataSet中
        /// </summary>
        /// <param name="spath">access数据库名</param>
        /// <param name="dataname">access数据库中的表名</param> 
        public bool readdata(string spath, string dataname)
        {
            try
            {
                //创建一个 OleDbConnection对象
                string strCon = " Provider = Microsoft.Jet.OLEDB.4.0 ; Data Source = " + spath;
                OleDbConnection myConn = new OleDbConnection(strCon);
               // string strCom = " SELECT * FROM " + dataname + " ORDER BY  id";
                string strCom = " SELECT * FROM " + dataname ;
                //创建一个 DataSet对象
                myConn.Open();
                OleDbDataAdapter myCommand = new OleDbDataAdapter(strCom, myConn);
                myCommand.Fill(this.dataSet1, dataname);
                myConn.Close();
                return true;
            }
            catch (Exception e)
            {
               // MessageBox.Show("连接数据库发生错误：" + e.ToString(), "错误！", MessageBoxButtons.OK, MessageBoxIcon.Error);
                return false;
            }
        }
     

新增记录/// <summary>
        /// 新增记录
        /// </summary>
        /// <param name="spath">数据库全名</param>
        /// <param name="dataname">表名</param>
        /// <param name="captions">字段名</param>
        /// <param name="items">添加的纪录内容</param>
        public void newdata(string spath, string dataname, string[] captions, object[] items)
        {
            try
            {
                //连接到一个数据库
                string strCon = " Provider = Microsoft.Jet.OLEDB.4.0 ; Data Source = " + spath;
                OleDbConnection myConn = new OleDbConnection(strCon);
                myConn.Open();
                string strInsert;
                int tt = captions.Length;
                int sign = -1;//记录日期字段所在索引号,用来格式化日期格式(只要日期,不要时间)

                strInsert = " INSERT INTO " + dataname + " ( "
                     + captions[0] + " , ";

                for (int i = 1; i < tt - 1; i++)
                {
                    if (captions[i].Contains("日期"))
                    {
                        sign = i;
                    }                
                    strInsert += captions[i] + " , ";
                }
                strInsert += captions[tt - 1] + " ) VALUES ( ' ";

                for (int i = 0; i < tt - 1; i++)
                {
                    if (i == sign)
                    {
                        string[] ss = items[i].ToString().Split(' ');
                        strInsert += ss[0] + " ' , ' ";
                    }
                    else
                    {
                        strInsert += items[i].ToString() + " ' , ' ";
                    }
                }
                strInsert += items[tt - 1].ToString() + "  ') ";
             
                OleDbCommand myCommand = new OleDbCommand(strInsert, myConn);
                myCommand.ExecuteNonQuery();
                myConn.Close();
            }
            catch (Exception ed)
            {
                MessageBox.Show("新增记录错误信息： " + ed.ToString(), "错误！", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
        }
     

搜索access数据库         /// <summary>
        /// 搜索access数据库
        /// </summary>
        /// <param name="spath">access数据库名</param>
        /// <param name="dataname">access数据库中的表名</param> 
        /// <param name="key">搜索关键字</param>
        /// <returns></returns>
        public bool searchdata(string spath, string dataname, string keyword)
        {
            string str = "";
            bool yn = false;
            //创建一个 OleDbConnection对象
            string strCon = " Provider = Microsoft.Jet.OLEDB.4.0 ; Data Source = " + spath;
            OleDbConnection myConn = new OleDbConnection(strCon);
            string strCom = " SELECT * FROM " + dataname + " WHERE " + keyword;
            try
            {
                myConn.Open();
                OleDbDataAdapter myCommand = new OleDbDataAdapter(strCom, myConn);
                myCommand.Fill(this.dataSet1, "search");
                yn = true;
            }
            catch (Exception e)
            {
                MessageBox.Show("发生错误：" + e.ToString(), "错误！", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
            finally
            {
                myConn.Close();
             }
             return yn;
       
        }
      查询条件关键字

名称	实例
=(等于)	select * from scott.emp where job=’MANAGER’;
select * from scott.emp where sal=1100;
!= (不等于)	select * from scott.emp where job!=’MANAGER’;
select * from scott.emp where sal!=1100;
^=(不等于)	select * from scott.emp where job^=’MANAGER’;
select * from scott.emp where sal^=1100;
<>(不等于)	select * from scott.emp where job<>’MANAGER’;
select * from scott.emp where sal<>1100;
<(小于)	select * from scott.emp where sal<2000;
select * from scott.emp where job<’MANAGER’;
>(大于)	select * from scott.emp where sal>2000;
select * from scott.emp where job>’MANAGER’;
<=(小于等于)	select * from scott.emp where sal<＝2000;
select * from scott.emp where job<＝’MANAGER’;
>=(大于等于)	select * from scott.emp where sal>=2000;
select * from scott.emp where job>=’MANAGER’;
in(列表)	select * from scott.emp where sal in (2000,1000,3000);
select * from scott.emp where job in (’MANAGER’,’CLERK’);
not in(不在列表)	select * from scott.emp where sal not in (2000,1000,3000);
select * from scott.emp where job not in (’MANAGER’,’CLERK’);
between(介于之间)	select * from scott.emp where sal between 2000 and 3000;
select * from scott.emp where job between ’MANAGER’ and ’CLERK’;
not between (不介于之间)	select * from scott.emp where sal not between 2000 and 3000;
select * from scott.emp where job not between ’MANAGER’ and ’CLERK’;
like(模式匹配)	select * from scott.emp where job like ’M%’;
select * from scott.emp where job like ’M__’;
not like (模式不匹配)	select * from scott.emp where job not like ’M%’;
select * from scott.emp where job not like ’M__’;
Is null (是否为空)	select * from scott.emp where sal is null;
select * from scott.emp where job is null;
is not null(是否为空)	select * from scott.emp where sal is not null;
select * from scott.emp where job is not null;

    like和not like适合字符型字段的查询，%%代表任意长度的字符串，_下划线代表一个任意的字符。like ‘m%%’ 代表m开头的任意长度的字符串，like ‘m__’ 代表m开头的长度为3的字符串。ADO中的通配符是两个"%%",还有上面的关键自都要大写,条件中的值大多要有用单引号括起来.