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 JonseTest 
{ 
  public 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); 
            } 
        } 
 
        // 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, "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);
       }