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使用DataSet更新数据库的方法

2023-05-11 12:02:27
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以前经常用sql语句(update)更新数据库,有使用用起来不是很方便,特别是数据量比较大的情况下(比如数据表)很麻烦~~后来感觉用DataSet更新数据库是不错的选择.于是急着写了一个用DataSet更新数据库的类如下:(后面有使用说明,总结)

using System;
        using System.Data;
        using System.Data.SqlClient;
        using System.Windows.Forms;
        namespace winApplication
        {
                 public class sqlAccess
                 {
                         //与SQL Server的连接字符串设置
                         private string _connString; 
                        private string _strSql;
                         private SqlCommandBuilder sqlCmdBuilder; 
                        private DataSet ds = new DataSet( ); 
                        private SqlDataAdapter da; 
                        public sqlAccess( string connString, string strSql ) 
                        { 
                                this._connString=connString; 
                        }
                         private SqlConnection GetConn( )
                         {
                                 try
                                   {
                                         SqlConnection Connection = new SqlConnection( this._connString ); 
                                         Connection.Open( ); 
                                        return Connection; 
                                   }
                                 catch ( Exception ex )
                                 {
                                         MessageBox.Show( ex.Message,"数据库连接失败" );
                                         throw; 
                                }
                         }
                         //根据输入的SQL语句检索数据库数据 
                        public DataSet SelectDb( string strSql, string strTableName )
                         {
                                 try
                                 {
                                         this._strSql = strSql;
                                         this.da = new SqlDataAdapter( this._strSql, this.GetConn( ) ); 
                                        this.ds.Clear( );
                                         this.da.Fill( ds,strTableName ); 
                                        return ds;
                                         //返回填充了数据的DataSet,其中数据表以strTableName给出的字符串命名
                                 }
                                 catch ( Exception ex )
                                 {
                                         MessageBox.Show( ex.Message,"数据库操作失败" ); 
                                        throw; 
                                }
                         }
                         //数据库数据更新( 传DataSet和DataTable的对象 ) 
                        public DataSet UpdateDs( DataSet changedDs, string tableName )
                         {
                                 try
                                 {
                                        this.da = new SqlDataAdapter( this._strSql, this.GetConn( ) ); 
                                        this.sqlCmdBuilder = new SqlCommandBuilder( da );
                                        this.da.Update( changedDs,tableName ); 
                                        changedDs.AcceptChanges( );
                                        return changedDs; 
                                        //返回更新了的数据库表
                                }
                                catch ( Exception ex )
                                {
                                        MessageBox.Show( ex.Message,"数据库更新失败" );
                                        throw; 
                                }
                }

 使用说明总结:

 1. GetConn方法创建一个数据库连接,返回SqlConnection.

 2.使用的selectming令中必须包含主键,这点大家都知道的!

3. this.da.Fill( ds,strTableName ) 填充数据集

4.构造CommandBuilder对象时,将DataAdapter对象作为构造函数参数传入:

this.sqlCmdBuilder = new SqlCommandBuilder( da );

5. 在调用UpdateDs( )更新数据库前,请检查changedDs是否已经被更新过,用

changedDs.[tableName] GetChanges( ) != null;

6.用 this.da.Update( changedDs,tableName )方法更新数据,然后调用changedDs.AcceptChanges( )才能真正的更新数据库,调用 changedDs.RejectChanges( ) 取消更新.

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