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);
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持查字典教程网。
【C#实现较为实用的SQLhelper】相关文章：
★ C#用Activex实现Web客户端读取RFID功能的代码