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 ConnStr

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

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, "id", "test"); string sSql = "update test set name='name_jonse',remark='remark_jonse' where id=" + iMaxID; sError = string.Empty; bool bResult = SqlServerHelper.UpdateData(out sError, sSql, true); if (bResult) Common.DisplayMsg(this.Text, "修改成功"); else Common.DisplayMsg(this.Text, sError);

InitGrid();

// 删除

sError = string.Empty; int iMaxID = SqlServerHelper.GetMaxID(out sError, "id", "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); }