数据库连接的多种方式（二）

/// <summary>
/// 执行查询语句，返回DataSet
/// </summary>
/// <param name="SQLString">查询语句</param>
/// <returns>DataSet</returns>
public static DataSet Query(string SQLString, params SqlParameter[] cmdParms)
{
conn = new SqlConnection(connectionString);
SqlCommand cmd = new SqlCommand();
PrepareCommand(cmd, conn, null, SQLString, cmdParms);
using (SqlDataAdapter da = new SqlDataAdapter(cmd))
{
DataSet ds = new DataSet();
try
{
da.Fill(ds, "ds");
cmd.Parameters.Clear();
}
catch (System.Data.SqlClient.SqlException ex)
{
throw new Exception(ex.Message);
}
return ds;
}

}

private static void PrepareCommand(SqlCommand cmd, SqlConnection conn, SqlTransaction trans, string cmdText,

SqlParameter[] cmdParms)
{
if (conn.State != ConnectionState.Open)
conn.Open();
cmd.Connection = conn;
cmd.CommandText = cmdText;
if (trans != null)
cmd.Transaction = trans;
cmd.CommandType = CommandType.Text;//cmdType;
if (cmdParms != null)
{
foreach (SqlParameter parm in cmdParms)
cmd.Parameters.Add(parm);
}

}

#endregion

#region 存储过程操作

/// <summary>
/// 执行存储过程
/// </summary>
/// <param name="storedProcName">存储过程名</param>
/// <param name="parameters">存储过程参数</param>
/// <returns>SqlDataReader</returns>
public static SqlDataReader RunProcedure(string storedProcName, IDataParameter[] parameters)
{
conn = new SqlConnection(connectionString);
SqlDataReader returnReader;
conn.Open();
SqlCommand command = BuildQueryCommand(conn, storedProcName, parameters);
command.CommandType = CommandType.StoredProcedure;
returnReader = command.ExecuteReader();
return returnReader;
}

/// <summary>
/// 执行存储过程
/// </summary>
/// <param name="storedProcName">存储过程名</param>
/// <param name="parameters">存储过程参数</param>
/// <param name="tableName">DataSet结果中的表名</param>
/// <returns>DataSet</returns>
public static DataSet RunProcedure(string storedProcName, IDataParameter[] parameters, string tableName)
{
conn = new SqlConnection(connectionString);
{
DataSet dataSet = new DataSet();
conn.Open();
SqlDataAdapter sqlDA = new SqlDataAdapter();
sqlDA.SelectCommand = BuildQueryCommand(conn, storedProcName, parameters);
sqlDA.Fill(dataSet, tableName);
conn.Close();
return dataSet;
}
}

/// <summary>
/// 构建 SqlCommand 对象(用来返回一个结果集，而不是一个整数值)
/// </summary>
/// <param name="connection">数据库连接</param>
/// <param name="storedProcName">存储过程名</param>
/// <param name="parameters">存储过程参数</param>
/// <returns>SqlCommand</returns>
private static SqlCommand BuildQueryCommand(SqlConnection conn, string storedProcName, IDataParameter[] parameters)
{
SqlCommand command = new SqlCommand(storedProcName, conn);
command.CommandType = CommandType.StoredProcedure;
foreach (SqlParameter parameter in parameters)
{
command.Parameters.Add(parameter);
}
return command;
}

/// <summary>
/// 执行存储过程，返回影响的行数
/// </summary>
/// <param name="storedProcName">存储过程名</param>
/// <param name="parameters">存储过程参数</param>
/// <param name="rowsAffected">影响的行数</param>
/// <returns></returns>
public static int RunProcedure(string storedProcName, IDataParameter[] parameters, out int rowsAffected)
{
conn = new SqlConnection(connectionString);
int result;
conn.Open();
SqlCommand command = BuildIntCommand(conn, storedProcName, parameters);
rowsAffected = command.ExecuteNonQuery();
result = (int)command.Parameters["ReturnValue"].Value;
conn.Close();
return result;
}
private static SqlCommand BuildIntCommand(SqlConnection conn, string storedProcName, IDataParameter[] parameters)
{
SqlCommand command = BuildQueryCommand(conn, storedProcName, parameters);
command.Parameters.Add(new SqlParameter("ReturnValue",
SqlDbType.Int, 4, ParameterDirection.ReturnValue,
false, 0, 0, string.Empty, DataRowVersion.Default, null));
return command;
}
#endregion

}