C#实现较为实用的SQLhelper

第一次写博客，想不到写什么好b（￣▽￣）d　，考虑的半天决定从sqlhelper开始，sqlhelper对程序员来说就像helloworld一样，很简单却又很重要，helloworld代表着程序员萌新第一次写代码，而sqlhelper则是初次接触数据库（不知道这种说法对不对）。

好了不废话了，下面直接上代码（无话可说了）：

public class SQLHelper
  {
    // 超时时间
    private static int Timeout = 1000;
    // 数据库名称
    public const String BestNet = "BestNet";
    //存储过程名称
    public const String UserInfoCURD = "UserInfoCURD";
    // 数据库连接字符串
    private static Dictionary<String, String> ConnStrs = new Dictionary<String, String>();

    /// <summary>
    /// SQLServer操作类(静态构造函数)
    /// </summary>
    static SQLHelper()
    {
      ConnectionStringSettingsCollection configs = WebConfigurationManager.ConnectionStrings;
      foreach (ConnectionStringSettings config in configs)
      {
        ConnStrs.Add(config.Name, config.ConnectionString);
      }
    }

    /// <summary>
    /// 获取数据库连接
    /// </summary>
    /// <param name="database">数据库(配置文件内connectionStrings的name)</param>
    /// <returns>数据库连接</returns>
    private static SqlConnection GetConnection(string database)
    {
      if (string.IsNullOrEmpty(database))
      {
        throw new Exception("未设置参数：database");
      }
      if (!ConnStrs.ContainsKey(database))
      {
        throw new Exception("未找到数据库：" + database);
      }
      return new SqlConnection(ConnStrs[database]);
    }

    /// <summary>
    /// 获取SqlCommand
    /// </summary>
    /// <param name="conn">SqlConnection</param>
    /// <param name="transaction">SqlTransaction</param>
    /// <param name="cmdType">CommandType</param>
    /// <param name="sql">SQL</param>
    /// <param name="parms">SqlParameter数组</param>
    /// <returns></returns>
    private static SqlCommand GetCommand(SqlConnection conn, SqlTransaction transaction, CommandType cmdType, string sql, SqlParameter[] parms)
    {
      SqlCommand cmd = new SqlCommand(sql, conn);
      cmd.CommandType = cmdType;
      cmd.CommandTimeout = Timeout;
      if (transaction != null)
        cmd.Transaction = transaction;
      if (parms != null && parms.Length != 0)
        cmd.Parameters.AddRange(parms);
      return cmd;
    }

    /// <summary>
    /// 查询数据，返回DataTable
    /// </summary>
    /// <param name="database">数据库</param>
    /// <param name="sql">SQL语句或存储过程名</param>
    /// <param name="parms">参数</param>
    /// <param name="cmdType">查询类型(SQL语句/存储过程名)</param>
    /// <returns>DataTable</returns>
    public static DataTable QueryDataTable(string database, string sql, SqlParameter[] parms, CommandType cmdType)
    {
      if (string.IsNullOrEmpty(database))
      {
        throw new Exception("未设置参数：database");
      }
      if (string.IsNullOrEmpty(sql))
      {
        throw new Exception("未设置参数：sql");
      }

      try
      {
        using (SqlConnection conn = GetConnection(database))
        {
          conn.Open();

          using (SqlCommand cmd = GetCommand(conn, null, cmdType, sql, parms))
          {
            using (SqlDataAdapter da = new SqlDataAdapter(cmd))
            {
              DataTable dt = new DataTable();
              da.Fill(dt);
              return dt;
            }
          }
        }
      }
      catch (SqlException ex)
      {
        System.Text.StringBuilder log = new System.Text.StringBuilder();
        log.Append("查询数据出错：");
        log.Append(ex);
        throw new Exception(log.ToString());
      }
    }

    /// <summary>
    /// 查询数据，返回DataSet
    /// </summary>
    /// <param name="database">数据库</param>
    /// <param name="sql">SQL语句或存储过程名</param>
    /// <param name="parms">参数</param>
    /// <param name="cmdType">查询类型(SQL语句/存储过程名)</param>
    /// <returns>DataSet</returns>
    public static DataSet QueryDataSet(string database, string sql, SqlParameter[] parms, CommandType cmdType)
    {
      if (string.IsNullOrEmpty(database))
      {
        throw new Exception("未设置参数：database");
      }
      if (string.IsNullOrEmpty(sql))
      {
        throw new Exception("未设置参数：sql");
      }

      try
      {
        using (SqlConnection conn = GetConnection(database))
        {
          conn.Open();

          using (SqlCommand cmd = GetCommand(conn, null, cmdType, sql, parms))
          {
            using (SqlDataAdapter da = new SqlDataAdapter(cmd))
            {
              DataSet ds = new DataSet();
              da.Fill(ds);
              return ds;
            }
          }
        }
      }
      catch (SqlException ex)
      {
        System.Text.StringBuilder log = new System.Text.StringBuilder();
        log.Append("查询数据出错：");
        log.Append(ex);
        throw new Exception(log.ToString());
      }
    }

    /// <summary>
    /// 执行命令获取唯一值(第一行第一列)
    /// </summary>
    /// <param name="database">数据库</param>
    /// <param name="sql">SQL语句或存储过程名</param>
    /// <param name="parms">参数</param>
    /// <param name="cmdType">查询类型(SQL语句/存储过程名)</param>
    /// <returns>获取值</returns>
    public static object QueryScalar(string database, string sql, SqlParameter[] parms, CommandType cmdType)
    {
      if (string.IsNullOrEmpty(database))
      {
        throw new Exception("未设置参数：database");
      }
      if (string.IsNullOrEmpty(sql))
      {
        throw new Exception("未设置参数：sql");
      }
      try
      {
        using (SqlConnection conn = GetConnection(database))
        {
          conn.Open();

          using (SqlCommand cmd = GetCommand(conn, null, cmdType, sql, parms))
          {
            return cmd.ExecuteScalar();
          }
        }
      }
      catch (SqlException ex)
      {
        System.Text.StringBuilder log = new System.Text.StringBuilder();
        log.Append("处理出错：");
        log.Append(ex);
        throw new Exception(log.ToString());
      }
    }

    /// <summary>
    /// 执行命令更新数据
    /// </summary>
    /// <param name="database">数据库</param>
    /// <param name="sql">SQL语句或存储过程名</param>
    /// <param name="parms">参数</param>
    /// <param name="cmdType">查询类型(SQL语句/存储过程名)</param>
    /// <returns>更新的行数</returns>
    public static int Execute(string database, string sql, SqlParameter[] parms, CommandType cmdType)
    {
      if (string.IsNullOrEmpty(database))
      {
        throw new Exception("未设置参数：database");
      }
      if (string.IsNullOrEmpty(sql))
      {
        throw new Exception("未设置参数：sql");
      }

      //返回(增删改)的更新行数
      int count = 0;

      try
      {
        using (SqlConnection conn = GetConnection(database))
        {
          conn.Open();

          using (SqlCommand cmd = GetCommand(conn, null, cmdType, sql, parms))
          {
            if (cmdType == CommandType.StoredProcedure)
              cmd.Parameters.AddWithValue("@RETURN_VALUE", "").Direction = ParameterDirection.ReturnValue;

            count = cmd.ExecuteNonQuery();

            if (count <= 0)
              if (cmdType == CommandType.StoredProcedure)
                count = (int)cmd.Parameters["@RETURN_VALUE"].Value;
          }
        }
      }
      catch (SqlException ex)
      {
        System.Text.StringBuilder log = new System.Text.StringBuilder();
        log.Append("处理出错：");
        log.Append(ex);
        throw new Exception(log.ToString());
      }
      return count;
    }

    /// <summary>
    /// 查询数据，返回DataTable
    /// </summary>
    /// <param name="database">数据库</param>
    /// <param name="sql">SQL语句或存储过程名</param>
    /// <param name="cmdType">查询类型(SQL语句/存储过程名)</param>
    /// <param name="values">参数</param>
    /// <returns>DataTable</returns>
    public static DataTable QueryDataTable(string database, string sql, CommandType cmdType, IDictionary<string, object> values)
    {
      SqlParameter[] parms = DicToParams(values);
      return QueryDataTable(database, sql, parms, cmdType);
    }

    /// <summary>
    /// 执行存储过程查询数据，返回DataSet
    /// </summary>
    /// <param name="database">数据库</param>
    /// <param name="sql">SQL语句或存储过程名</param>
    /// <param name="cmdType">查询类型(SQL语句/存储过程名)</param>
    /// <param name="values">参数
    /// <returns>DataSet</returns>
    public static DataSet QueryDataSet(string database, string sql, CommandType cmdType, IDictionary<string, object> values)
    {
      SqlParameter[] parms = DicToParams(values);
      return QueryDataSet(database, sql, parms, cmdType);
    }

    /// <summary>
    /// 执行命令获取唯一值(第一行第一列)
    /// </summary>
    /// <param name="database">数据库</param>
    /// <param name="sql">SQL语句或存储过程名</param>
    /// <param name="cmdType">查询类型(SQL语句/存储过程名)</param>
    /// <param name="values">参数</param>
    /// <returns>唯一值</returns>
    public static object QueryScalar(string database, string sql, CommandType cmdType, IDictionary<string, object> values)
    {
      SqlParameter[] parms = DicToParams(values);
      return QueryScalar(database, sql, parms, cmdType);
    }

    /// <summary>
    /// 执行命令更新数据
    /// </summary>
    /// <param name="database">数据库</param>
    /// <param name="sql">SQL语句或存储过程名</param>
    /// <param name="cmdType">查询类型(SQL语句/存储过程名)</param>
    /// <param name="values">参数</param>
    /// <returns>更新的行数</returns>
    public static int Execute(string database, string sql, CommandType cmdType, IDictionary<string, object> values)
    {
      SqlParameter[] parms = DicToParams(values);
      return Execute(database, sql, parms, cmdType);
    }

    /// <summary>
    /// 创建参数
    /// </summary>
    /// <param name="name">参数名</param>
    /// <param name="type">参数类型</param>
    /// <param name="size">参数大小</param>
    /// <param name="direction">参数方向(输入/输出)</param>
    /// <param name="value">参数值</param>
    /// <returns>新参数对象</returns>
    public static SqlParameter[] DicToParams(IDictionary<string, object> values)
    {
      if (values == null) return null;

      SqlParameter[] parms = new SqlParameter[values.Count];
      int index = 0;
      foreach (KeyValuePair<string, object> kv in values)
      {
        SqlParameter parm = null;
        if (kv.Value == null)
        {
          parm = new SqlParameter(kv.Key, DBNull.Value);
        }
        else
        {
          Type t = kv.Value.GetType();
          parm = new SqlParameter(kv.Key, NetToSql(kv.Value.GetType()));
          parm.Value = kv.Value;
        }

        parms[index++] = parm;
      }
      return parms;
    }

    /// <summary>
    /// .net类型转换为Sql类型
    /// </summary>
    /// <param name="t">.net类型</param>
    /// <returns>Sql类型</returns>
    public static SqlDbType NetToSql(Type t)
    {
      SqlDbType dbType = SqlDbType.Variant;
      switch (t.Name)
      {
        case "Int16":
          dbType = SqlDbType.SmallInt;
          break;
        case "Int32":
          dbType = SqlDbType.Int;
          break;
        case "Int64":
          dbType = SqlDbType.BigInt;
          break;
        case "Single":
          dbType = SqlDbType.Real;
          break;
        case "Decimal":
          dbType = SqlDbType.Decimal;
          break;

        case "Byte[]":
          dbType = SqlDbType.VarBinary;
          break;
        case "Boolean":
          dbType = SqlDbType.Bit;
          break;
        case "String":
          dbType = SqlDbType.NVarChar;
          break;
        case "Char[]":
          dbType = SqlDbType.Char;
          break;
        case "DateTime":
          dbType = SqlDbType.DateTime;
          break;
        case "DateTime2":
          dbType = SqlDbType.DateTime2;
          break;
        case "DateTimeOffset":
          dbType = SqlDbType.DateTimeOffset;
          break;
        case "TimeSpan":
          dbType = SqlDbType.Time;
          break;
        case "Guid":
          dbType = SqlDbType.UniqueIdentifier;
          break;
        case "Xml":
          dbType = SqlDbType.Xml;
          break;
        case "Object":
          dbType = SqlDbType.Variant;
          break;
      }
      return dbType;
    }

  }

可以直接这样调用：

IDictionary<string, object> values = new Dictionary<string, object>();
 values.Add("@UserName", UserName);
 values.Add("@PassWord", passWord);
 object Scalar = SQLHelper.QueryScalar(SQLHelper.BestNet, SQLHelper.UserInfoCURD, CommandType.StoredProcedure, values);  

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