用于SqlServer数据库的SqlServerHelper.cs类，及其调用例子

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using System.Configuration;
using System.Data;
using System.Data.sqlClient;

namespace demo
{
    public abstract class sqlServerHelper
    {
        public static string ConnString = string.Empty;

        public static string Conn_Config_Str_Name = string.Empty;

        public static string Conn_Server = string.Empty;
        public static string Conn_dbname = string.Empty;
        public static string Conn_Uid = string.Empty;
        public static string Conn_Pwd = string.Empty;

        private static string _ConnString
        {
            get
            {
                if (!string.IsNullOrEmpty(ConnString))
                    return ConnString;

                object oConn = ConfigurationManager.ConnectionStrings[Conn_Config_Str_Name];
                if (oConn != null && oConn.ToString() != "")
                    return oConn.ToString();

                return string.Format(@"server={0};database={1};uid={2};password={3}",Conn_Server,Conn_dbname,Conn_Uid,Conn_Pwd);
            }
        }

        // 测试连接
        public static bool TestConn()
        {
            sqlConnection myConn = null;
            bool bResult = false;
            try
            {
                myConn = new sqlConnection(_ConnString);
                myConn.open();
            }
            catch (Exception ex)
            {
            }
            finally
            {
                if (myConn != null && myConn.State.ToString() == "Open")
                    bResult = true;
            }

            myConn.Close();

            return bResult;
        }

        // 取datatable
        public static DataTable GetDataTable(out string sError,string ssql)
        {
            DataTable dt = null;
            sError = string.Empty;

            try
            {
                sqlConnection conn = new sqlConnection(_ConnString);
                sqlCommand comm = new sqlCommand();
                comm.Connection = conn;
                comm.CommandText = ssql;
                sqlDataAdapter dapter = new sqlDataAdapter(comm);
                dt = new DataTable();
                dapter.Fill(dt);
            }
            catch (Exception ex)
            {
                sError = ex.Message;
            }

            return dt;
        }

        // 取dataset
        public static DataSet GetDataSet(out string sError,string ssql)
        {
            DataSet ds = null;
            sError = string.Empty;

            try
            {
                sqlConnection conn = new sqlConnection(_ConnString);
                sqlCommand comm = new sqlCommand();
                comm.Connection = conn;
                comm.CommandText = ssql;
                sqlDataAdapter dapter = new sqlDataAdapter(comm);
                ds = new DataSet();
                dapter.Fill(ds);
            }
            catch (Exception ex)
            {
                sError = ex.Message;
            }

            return ds;
        }

        // 取某个单一的元素
        public static object GetSingle(out string sError,string ssql)
        {
            DataTable dt = GetDataTable(out sError,ssql);
            if (dt != null && dt.Rows.Count > 0)
            {
                return dt.Rows[0][0];
            }

            return null;
        }

        // 取最大的ID
        public static Int32 GetMaxID(out string sError,string sKeyField,string sTableName)
        {
            DataTable dt = GetDataTable(out sError,"select isnull(max([" + sKeyField + "]),0) as MaxID from [" + sTableName + "]");
            if (dt != null && dt.Rows.Count > 0)
            {
                return Convert.ToInt32(dt.Rows[0][0].ToString());
            }

            return 0;
        }

        // 执行 insert,update,delete 动作，也可以使用事务
        public static bool UpdateData(out string sError,string ssql,bool bUseTransaction = false)
        {
            int iResult = 0;
            sError = string.Empty;

            if (!bUseTransaction)
            {
                try
                {
                    sqlConnection conn = new sqlConnection(_ConnString);
                    if (conn.State != ConnectionState.Open)
                        conn.open();
                    sqlCommand comm = new sqlCommand();
                    comm.Connection = conn;
                    comm.CommandText = ssql;
                    iResult = comm.ExecuteNonQuery();
                }
                catch (Exception ex)
                {
                    sError = ex.Message;
                    iResult = -1;
                }
            }
            else // 使用事务
            {
                sqlTransaction trans = null;
                try
                {
                    sqlConnection conn = new sqlConnection(_ConnString);
                    if (conn.State != ConnectionState.Open)
                        conn.open();
                    trans = conn.BeginTransaction();
                    sqlCommand cmd = new sqlCommand();
                    cmd.Connection = conn;
                    cmd.CommandText = ssql;
                    cmd.Transaction = trans;
                    iResult = cmd.ExecuteNonQuery();
                    trans.Commit();
                }
                catch (Exception ex)
                {
                    sError = ex.Message;
                    iResult = -1;
                    trans.Rollback();
                }
            }

            return iResult > 0;
        }

    }
}

调用方法：

 

一，先设置数据库连接的信息

            //sqlServerHelper.ConnString = @"server=电脑名 或 电脑IP;database=数据库名;uid=数据库登录名;password=数据库登录密码";

            sqlServerHelper.Conn_Config_Str_Name = @"ConnString";  // ConnString的信息在 App.Config里设置                         //sqlServerHelper.Conn_Server = @"电脑名 或 电脑IP";            //sqlServerHelper.Conn_dbname = "数据库名";            //sqlServerHelper.Conn_Uid = "数据库登录名";            //sqlServerHelper.Conn_Pwd = "数据库登录密码";

 

二， App.Config

 

<?xml version="1.0" encoding="utf-8" ?><configuration>  <connectionStrings>    <add name="ConnString" connectionString="server=电脑名 或 电脑IP;database=数据库名;uid=数据库登录名;password=数据库登录密码" />  </connectionStrings></configuration>

 

三,  读取 datatable / dataset 数据

           private void InitGrid()           {

            string ssql = "select * from test";

            string sError = string.Empty;

            DataTable dt = sqlServerHelper.GetDataTable(out sError,ssql);

            //DataSet dt = sqlServerHelper.GetDataSet(out sError,ssql);

            dataGridView1.DataSource = dt;

            if (!string.IsNullOrEmpty(sError))                Common.displayMsg(this.Text,sError);

           }

 

四，插入，修改，删除 数据 （都调用sqlServerHelper.UpdateData方法）

            // 插入

            string  sError = string.Empty;            int iMaxID = sqlServerHelper.GetMaxID(out sError,"id","test") + 1;            string ssql = "insert into test select " + iMaxID + ",'name" + iMaxID + "','remark" + iMaxID + "'";            sError = string.Empty;            bool bResult = sqlServerHelper.UpdateData(out sError,ssql,true);            if (bResult)                Common.displayMsg(this.Text,"插入成功");            else                Common.displayMsg(this.Text,sError);

            InitGrid();

 

            // 修改

            sError = string.Empty;            int iMaxID = sqlServerHelper.GetMaxID(out sError,"test");            string ssql = "update test set name='name_jonse',remark='remark_jonse' where id=" + iMaxID;            sError = string.Empty;            bool bResult = sqlServerHelper.UpdateData(out sError,"修改成功");            else                Common.displayMsg(this.Text,sError);

            InitGrid();

 

             // 删除

            sError = string.Empty;            int iMaxID = sqlServerHelper.GetMaxID(out sError,"test");            string ssql = "delete from test where id=" + iMaxID;            sError = string.Empty;            bool bResult = sqlServerHelper.UpdateData(out sError,ssql);            if (bResult)                Common.displayMsg(this.Text,"删除成功");            else                Common.displayMsg(this.Text,sError);

            InitGrid();

 

五，其它

 

       public static void displayMsg(string sCaption,string sMsg)       {           sMsg = sMsg.TrimEnd('!').TrimEnd('！') + " !";           MessageBox.Show(sMsg,sCaption);       }