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
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); }