sqlHelper类

下面代码是本人封装的一个sqlHelper类。主要功能是对数据库的CURD。以及存储过程、事物、分页的实现。（首先要引入命名空间using System.Configuration;）

public class SqlHelper
{

#region 连接字符串
/// <summary>
/// 连接数据库的字符串
/// </summary>
private static string conStr = ConfigurationManager.ConnectionStrings["sqlconStr"].ConnectionString; 
#endregion

#region 01.执行查询返回datatable +DataTable ExecuteDataTable(string sql, params SqlParameter[] param)
/// <summary>
/// 返回datatable
/// </summary>
/// <param name="sql">sql语句</param>
/// <param name="param">数组型参数，sql语句需要替换的参数</param>
/// <returns>DataTable</returns>
public static DataTable ExecuteDataTable(string sql, params SqlParameter[] param)
{
DataTable dt = new DataTable();
using (SqlConnection con = new SqlConnection(conStr))
{
//con.ConnectionString = conStr; 
using (SqlCommand com = new SqlCommand(sql, con))
{
//com.CommandText = sql;
//com.Connection = con;
//com.CommandType = CommandType.Text;
//com.CommandTimeout = Convert.ToInt32(ConfigurationSettings.AppSettings["CommandTimeout"]); 
com.Parameters.AddRange(param); 
//创建适配器对象(卡车，它会自动开关连接通道)
SqlDataAdapter adapter = new SqlDataAdapter(com);
//adapter.SelectCommand = com;//也可以用这种方式联系command对象
adapter.Fill(dt);
com.Parameters.Clear();
return dt;
}
}
} 
#endregion

#region 02.返回非查询命令ExecuteNoQuery受影响的行数 +int ExecuteNoQuery(string sql, params SqlParameter[] param)
/// <summary>
/// 返回非查询命令ExecuteNoQuery受影响的行数
/// </summary>
/// <param name="sql">sql语句</param>
/// <param name="param">数组型参数，sql语句需要替换的参数</param>
/// <returns>返回受影响的行数</returns>
public static int ExecuteNoQuery(string sql, params SqlParameter[] param)
{
using (SqlConnection con = new SqlConnection(conStr))
{
using (SqlCommand com = new SqlCommand(sql, con))
{
com.Parameters.AddRange(param);
con.Open();
int count= com.ExecuteNonQuery();
com.Parameters.Clear();
return count;
}
}
} 
#endregion

#region 03.执行查询或者非查询， 返回结果集的第一行第一列 +object ExecuteScalar(string sql, params SqlParameter[] param)
/// <summary>
/// 执行查询或者非查询， 返回结果集的第一行第一列
/// </summary>
/// <param name="sql">sql语句</param>
/// <param name="param">数组型参数，sql语句需要替换的参数</param>
/// <returns>返回查询结果集的第一行第一列</returns>
public static object ExecuteScalar(string sql, params SqlParameter[] param)
{
using (SqlConnection con = new SqlConnection(conStr))
{
using (SqlCommand com = new SqlCommand(sql, con))
{
com.Parameters.AddRange(param);
con.Open(); 
object o= com.ExecuteScalar();
com.Parameters.Clear();
return o;

}
}
} 
#endregion

#region 04.返回 SqlDataReader + SqlDataReader ExecuteDataReader(string sql, params SqlParameter[] param)
/// <summary>
/// 返回datareader
/// </summary>
/// <param name="sql"></param>
/// <param name="param"></param>
/// <returns></returns>
public static SqlDataReader ExecuteDataReader(string sql, params SqlParameter[] param)
{
//因为 SqlDataReader 是基于连接的，所以不能在这里用using释放掉连接，不然返回的SqlDataReader就无法从数据库服务器一条一条的读取数据了
SqlConnection con = new SqlConnection(conStr);
SqlCommand com = new SqlCommand(sql, con);
if (param != null)
{
com.Parameters.AddRange(param);
}
con.Open();
//因为当读取完数据后又需要释放连接（连接是宝贵的），所以在这里为ExecuteReader（）方法加了一个枚举型参数CommandBehavior.CloseConnection，让datareader关闭时，自动的关闭connection的连接。
SqlDataReader reader= com.ExecuteReader(CommandBehavior.CloseConnection);
com.Parameters.Clear();
return reader;
} 
#endregion

#region 05.存储过程 返回数据
/// <summary>
/// 返回DataTable和pageCount
/// </summary>
/// <param name="sql"></param>
/// <param name="pageCount"></param>
/// <returns></returns>
public static DataTable ExecuteProc(string sql, int pageSize, int pageIndex, out int pageCount)
{
using (SqlConnection con = new SqlConnection(conStr))
{
//string sql = "usp_GetPageData";
using (SqlCommand com = new SqlCommand(sql, con))
{
com.CommandType = CommandType.StoredProcedure;//设置sql语句类型为存储过程

//设置存储过程的输入参数
com.Parameters.AddWithValue("@pageSize", pageSize);
com.Parameters.AddWithValue("@pageIndex", pageIndex);

//输出参数的设置
SqlParameter sp = com.Parameters.Add("@pageCount", SqlDbType.Int);
sp.Direction = ParameterDirection.Output;


DataTable dt = new DataTable();
using (SqlDataAdapter adaper = new SqlDataAdapter(com))
{
adaper.Fill(dt);
com.Parameters.Clear();
pageCount = Convert.ToInt32(sp.Value);//获取输出参数的值
return dt;
}
}
}
} 
#endregion

#region 06.分页返回数据 
/// <summary>
/// 分页返回数据
/// </summary>
/// <param name="sql">查询命令</param>
/// <param name="orderByKey">按降序或者升序获取数据 如：id desc</param>
/// <param name="pageIndex">要获取哪页的数据</param>
/// <param name="pageSize">页的大小</param>
/// <param name="totalRows">输出型参数：总数据行数目</param>
/// <param name="PageCount">输出型参数：总页数</param>
/// <param name="param">查询命令参数</param>
/// <returns>数据行集合dtatable</returns>
public static DataTable ExecuteSplitQueryData(string sql, string orderByKey, int pageIndex, int pageSize, out long totalRows, out long PageCount, params SqlParameter[] param)
{

string str = string.Format("select row_number()over(order by {0}) as rownumber,* from ({1}) as t", orderByKey, sql);
return ExecuteSplitQuery(str, orderByKey, pageIndex, pageSize, out totalRows, out PageCount, param);

}
private static DataTable ExecuteSplitQuery(string sql, string orderByKey, int pageIndex, int pageSize, out long totalRows, out long PageCount, params SqlParameter[] param)
{
//获取总行数
object count = ExecuteScalar(string.Format("select count(1) from ({0})t", sql), param);
totalRows = Convert.ToInt32(count);

//获取总页数
long pagecount = totalRows / pageSize;
long laterNum = totalRows % pageSize;
if (laterNum>0)
{
pagecount++;
}
PageCount = pagecount;

//获取分页后的数据
string str = string.Format("select * from ({0})t ", sql);
str += string.Format("where t.rownumber between {0} and {1} order by {2}", pageIndex * pageSize - pageSize + 1, pageIndex * pageSize, orderByKey); 
return ExecuteDataTable(str, param);
} 
#endregion

public static int ExecuteTransaction(IDictionary<string, SqlParameter[]> dics)
{ 
int n = 0;
SqlConnection con = new SqlConnection();
con.ConnectionString = conStr;
SqlCommand cmd = new SqlCommand();
cmd.Connection = con;
con.Open();
SqlTransaction myTransaction = con.BeginTransaction();
cmd.Transaction = myTransaction;
try
{
foreach (var dic in dics)
{
cmd.CommandText = dic.Key;
cmd.Parameters.Clear();
if (dic.Value != null)
{
cmd.Parameters.AddRange(dic.Value);
}
n += cmd.ExecuteNonQuery(); //循环执行命令
}
myTransaction.Commit(); //提交数据库事务
return n;
}
catch (System.Exception ex)
{
myTransaction.Rollback();
throw ex;
}
finally
{
con.Close();
}
}

public static int ExecuteUpdate(DataSet ds, params SqlParameter[] param)
{
using (SqlConnection con=new SqlConnection())
{
con.ConnectionString = conStr;
con.Open(); 
using (SqlCommand com=new SqlCommand())
{
com.Connection = con;
com.Parameters.AddRange(param);
SqlDataAdapter adapter = new SqlDataAdapter();
adapter.SelectCommand = com;
SqlCommandBuilder builder = new SqlCommandBuilder();
builder.DataAdapter = adapter;
return adapter.Update(ds);

}
}
}

}