【WPF学习笔记】之如何通过后台C#代码添加(增/删/改按钮)实现对SQLServer数据库数据的更改
首先,需要连接SQLServer数据库的服务器名称server、数据库名database、数据库用户名uid以及密码pwd,如下图:
然后需要以下数据库SQL代码段,还有一个myHelper.cs代码,粘贴复制即可:
DbHelperSQL.cs代码:
注意要更改红框中的内容
using System; using System.Collections; using System.Collections.Generic; using System.Data; using System.Data.SqlClient; using System.Configuration; namespace MTBug.sqlHelper { /// <summary> /// 数据访问抽象基础类 /// Copyright (C) Maticsoft /// </summary> public abstract class DbHelperSQL { //数据库连接字符串(web.config来配置),多数据库可使用DbHelperSQLP来实现. //public static string connectionString = @"server=localhost;database=MTBugList;uid=sa;pwd=123"; public static string connectionString = @"server=localhost;database=MTBugList;uid=sa;pwd=aaaaaa"; public DbHelperSQL() { //connectionString = @"server=" + System.Net.Dns.GetHostName() + ";database=TianZhong;uid=sa;pwd=" + myHelper.getXMLValue("dbUserPW"); connectionString = @"server=" + myHelper.getXMLValue("dbAddr") + ";database=MTBugList;uid=sa;pwd=" + myHelper.getXMLValue("dbUserPW"); } #region 公用方法 /// <summary> /// 判断是否存在某表的某个字段 /// </summary> /// <param name="tableName">表名称</param> /// <param name="columnName">列名称</param> /// <returns>是否存在</returns> public static bool ColumnExists(string tableName, string columnName) { string sql = "select count(1) from syscolumns where [id]=object_id('" + tableName + "') and [name]='" + columnName + "'"; object res = GetSingle(sql); if (res == null) { return false; } return Convert.ToInt32(res) > 0; } public static int GetMaxID(string FieldName, string TableName) { string strsql = "select max(" + FieldName + ")+1 from " + TableName; object obj = GetSingle(strsql); if (obj == null) { return 1; } else { return int.Parse(obj.ToString()); } } public static bool Exists(string strSql) { object obj = GetSingle(strSql); int cmdresult; if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value))) { cmdresult = 0; } else { cmdresult = int.Parse(obj.ToString()); //也可能=0 } if (cmdresult == 0) { return false; } else { return true; } } /// <summary> /// 表是否存在 /// </summary> /// <param name="TableName"></param> /// <returns></returns> public static bool TabExists(string TableName) { string strsql = "select count(*) from sysobjects where id = object_id(N'[" + TableName + "]') and OBJECTPROPERTY(id, N'IsUserTable') = 1"; //string strsql = "SELECT count(*) FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[" + TableName + "]') AND type in (N'U')"; object obj = GetSingle(strsql); int cmdresult; if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value))) { cmdresult = 0; } else { cmdresult = int.Parse(obj.ToString()); } if (cmdresult == 0) { return false; } else { return true; } } public static bool Exists(string strSql, params SqlParameter[] cmdParms) { object obj = GetSingle(strSql, cmdParms); int cmdresult; if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value))) { cmdresult = 0; } else { cmdresult = int.Parse(obj.ToString()); } if (cmdresult == 0) { return false; } else { return true; } } #endregion #region 执行简单SQL语句 /// <summary> /// 执行SQL语句,返回影响的记录数 /// </summary> /// <param name="SQLString">SQL语句</param> /// <returns>影响的记录数</returns> public static int ExecuteSql(string SQLString) { using (SqlConnection connection = new SqlConnection(connectionString)) { using (SqlCommand cmd = new SqlCommand(SQLString, connection)) { try { connection.Open(); int rows = cmd.ExecuteNonQuery(); return rows; } catch (System.Data.SqlClient.SqlException e) { connection.Close(); throw e; } } } } public static int ExecuteSqlByTime(string SQLString, int Times) { using (SqlConnection connection = new SqlConnection(connectionString)) { using (SqlCommand cmd = new SqlCommand(SQLString, connection)) { try { connection.Open(); cmd.CommandTimeout = Times; int rows = cmd.ExecuteNonQuery(); return rows; } catch (System.Data.SqlClient.SqlException e) { connection.Close(); throw e; } } } } /// <summary> /// 执行多条SQL语句,实现数据库事务。 /// </summary> /// <param name="SQLStringList">多条SQL语句</param> public static int ExecuteSqlTran(List<String> SQLStringList) { using (SqlConnection conn = new SqlConnection(connectionString)) { conn.Open(); SqlCommand cmd = new SqlCommand(); cmd.Connection = conn; SqlTransaction tx = conn.BeginTransaction(); cmd.Transaction = tx; try { int count = 0; for (int n = 0; n < SQLStringList.Count; n++) { string strsql = SQLStringList[n]; if (strsql.Trim().Length > 1) { cmd.CommandText = strsql; count += cmd.ExecuteNonQuery(); } } tx.Commit(); return count; } catch { tx.Rollback(); return 0; } } } /// <summary> /// 执行带一个存储过程参数的的SQL语句。 /// </summary> /// <param name="SQLString">SQL语句</param> /// <param name="content">参数内容,比如一个字段是格式复杂的文章,有特殊符号,可以通过这个方式添加</param> /// <returns>影响的记录数</returns> public static int ExecuteSql(string SQLString, string content) { using (SqlConnection connection = new SqlConnection(connectionString)) { SqlCommand cmd = new SqlCommand(SQLString, connection); System.Data.SqlClient.SqlParameter myParameter = new System.Data.SqlClient.SqlParameter("@content", SqlDbType.NText); myParameter.Value = content; cmd.Parameters.Add(myParameter); try { connection.Open(); int rows = cmd.ExecuteNonQuery(); return rows; } catch (System.Data.SqlClient.SqlException e) { throw e; } finally { cmd.Dispose(); connection.Close(); } } } /// <summary> /// 执行带一个存储过程参数的的SQL语句。 /// </summary> /// <param name="SQLString">SQL语句</param> /// <param name="content">参数内容,比如一个字段是格式复杂的文章,有特殊符号,可以通过这个方式添加</param> /// <returns>影响的记录数</returns> public static object ExecuteSqlGet(string SQLString, string content) { using (SqlConnection connection = new SqlConnection(connectionString)) { SqlCommand cmd = new SqlCommand(SQLString, connection); System.Data.SqlClient.SqlParameter myParameter = new System.Data.SqlClient.SqlParameter("@content", SqlDbType.NText); myParameter.Value = content; cmd.Parameters.Add(myParameter); try { connection.Open(); object obj = cmd.ExecuteScalar(); if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value))) { return null; } else { return obj; } } catch (System.Data.SqlClient.SqlException e) { throw e; } finally { cmd.Dispose(); connection.Close(); } } } /// <summary> /// 向数据库里插入图像格式的字段(和上面情况类似的另一种实例) /// </summary> /// <param name="strSQL">SQL语句</param> /// <param name="fs">图像字节,数据库的字段类型为image的情况</param> /// <returns>影响的记录数</returns> public static int ExecuteSqlInsertImg(string strSQL, byte[] fs) { using (SqlConnection connection = new SqlConnection(connectionString)) { SqlCommand cmd = new SqlCommand(strSQL, connection); System.Data.SqlClient.SqlParameter myParameter = new System.Data.SqlClient.SqlParameter("@fs", SqlDbType.Image); myParameter.Value = fs; cmd.Parameters.Add(myParameter); try { connection.Open(); int rows = cmd.ExecuteNonQuery(); return rows; } catch (System.Data.SqlClient.SqlException e) { throw e; } finally { cmd.Dispose(); connection.Close(); } } } /// <summary> /// 执行一条计算查询结果语句,返回查询结果(object)。 /// </summary> /// <param name="SQLString">计算查询结果语句</param> /// <returns>查询结果(object)</returns> public static object GetSingle(string SQLString) { using (SqlConnection connection = new SqlConnection(connectionString)) { using (SqlCommand cmd = new SqlCommand(SQLString, connection)) { try { connection.Open(); object obj = cmd.ExecuteScalar(); if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value))) { return null; } else { return obj; } } catch (System.Data.SqlClient.SqlException e) { connection.Close(); throw e; } } } } public static object GetSingle(string SQLString, int Times) { using (SqlConnection connection = new SqlConnection(connectionString)) { using (SqlCommand cmd = new SqlCommand(SQLString, connection)) { try { connection.Open(); cmd.CommandTimeout = Times; object obj = cmd.ExecuteScalar(); if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value))) { return null; } else { return obj; } } catch (System.Data.SqlClient.SqlException e) { connection.Close(); throw e; } } } } /// <summary> /// 执行查询语句,返回SqlDataReader ( 注意:调用该方法后,一定要对SqlDataReader进行Close ) /// </summary> /// <param name="strSQL">查询语句</param> /// <returns>SqlDataReader</returns> public static SqlDataReader ExecuteReader(string strSQL) { SqlConnection connection = new SqlConnection(connectionString); SqlCommand cmd = new SqlCommand(strSQL, connection); try { connection.Open(); SqlDataReader myReader = cmd.ExecuteReader(CommandBehavior.CloseConnection); return myReader; } catch (System.Data.SqlClient.SqlException e) { throw e; } } /// <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) { using (SqlConnection connection = new SqlConnection(connectionString)) { DataSet ds = new DataSet(); try { connection.Open(); SqlDataAdapter command = new SqlDataAdapter(SQLString, connection); command.Fill(ds, "ds"); } catch (System.Data.SqlClient.SqlException ex) { throw new Exception(ex.Message); } return ds; } } public static DataSet Query(string SQLString, int Times) { using (SqlConnection connection = new SqlConnection(connectionString)) { DataSet ds = new DataSet(); try { connection.Open(); SqlDataAdapter command = new SqlDataAdapter(SQLString, connection); command.SelectCommand.CommandTimeout = Times; command.Fill(ds, "ds"); } catch (System.Data.SqlClient.SqlException ex) { throw new Exception(ex.Message); } return ds; } } #endregion #region 执行带参数的SQL语句 /// <summary> /// 执行SQL语句,返回影响的记录数 /// </summary> /// <param name="SQLString">SQL语句</param> /// <returns>影响的记录数</returns> public static int ExecuteSql(string SQLString, params SqlParameter[] cmdParms) { using (SqlConnection connection = new SqlConnection(connectionString)) { using (SqlCommand cmd = new SqlCommand()) { try { PrepareCommand(cmd, connection, null, SQLString, cmdParms); int rows = cmd.ExecuteNonQuery(); cmd.Parameters.Clear(); return rows; } catch (System.Data.SqlClient.SqlException e) { throw e; } } } } /// <summary> /// 执行多条SQL语句,实现数据库事务。 /// </summary> /// <param name="SQLStringList">SQL语句的哈希表(key为sql语句,value是该语句的SqlParameter[])</param> public static void ExecuteSqlTran(Hashtable SQLStringList) { using (SqlConnection conn = new SqlConnection(connectionString)) { conn.Open(); using (SqlTransaction trans = conn.BeginTransaction()) { SqlCommand cmd = new SqlCommand(); try { //循环 foreach (DictionaryEntry myDE in SQLStringList) { string cmdText = myDE.Key.ToString(); SqlParameter[] cmdParms = (SqlParameter[])myDE.Value; PrepareCommand(cmd, conn, trans, cmdText, cmdParms); int val = cmd.ExecuteNonQuery(); cmd.Parameters.Clear(); } trans.Commit(); } catch { trans.Rollback(); throw; } } } } /// <summary> /// 执行多条SQL语句,实现数据库事务。 /// </summary> /// <param name="SQLStringList">SQL语句的哈希表(key为sql语句,value是该语句的SqlParameter[])</param> public static int ExecuteSqlTran(System.Collections.Generic.List<CommandInfo> cmdList) { using (SqlConnection conn = new SqlConnection(connectionString)) { conn.Open(); using (SqlTransaction trans = conn.BeginTransaction()) { SqlCommand cmd = new SqlCommand(); try { int count = 0; //循环 foreach (CommandInfo myDE in cmdList) { string cmdText = myDE.CommandText; SqlParameter[] cmdParms = (SqlParameter[])myDE.Parameters; PrepareCommand(cmd, conn, trans, cmdText, cmdParms); if (myDE.EffentNextType == EffentNextType.WhenHaveContine || myDE.EffentNextType == EffentNextType.WhenNoHaveContine) { if (myDE.CommandText.ToLower().IndexOf("count(") == -1) { trans.Rollback(); return 0; } object obj = cmd.ExecuteScalar(); bool isHave = false; if (obj == null && obj == DBNull.Value) { isHave = false; } isHave = Convert.ToInt32(obj) > 0; if (myDE.EffentNextType == EffentNextType.WhenHaveContine && !isHave) { trans.Rollback(); return 0; } if (myDE.EffentNextType == EffentNextType.WhenNoHaveContine && isHave) { trans.Rollback(); return 0; } continue; } int val = cmd.ExecuteNonQuery(); count += val; if (myDE.EffentNextType == EffentNextType.ExcuteEffectRows && val == 0) { trans.Rollback(); return 0; } cmd.Parameters.Clear(); } trans.Commit(); return count; } catch { trans.Rollback(); throw; } } } } /// <summary> /// 执行多条SQL语句,实现数据库事务。 /// </summary> /// <param name="SQLStringList">SQL语句的哈希表(key为sql语句,value是该语句的SqlParameter[])</param> public static void ExecuteSqlTranWithIndentity(System.Collections.Generic.List<CommandInfo> SQLStringList) { using (SqlConnection conn = new SqlConnection(connectionString)) { conn.Open(); using (SqlTransaction trans = conn.BeginTransaction()) { SqlCommand cmd = new SqlCommand(); try { int indentity = 0; //循环 foreach (CommandInfo myDE in SQLStringList) { string cmdText = myDE.CommandText; SqlParameter[] cmdParms = (SqlParameter[])myDE.Parameters; foreach (SqlParameter q in cmdParms) { if (q.Direction == ParameterDirection.InputOutput) { q.Value = indentity; } } PrepareCommand(cmd, conn, trans, cmdText, cmdParms); int val = cmd.ExecuteNonQuery(); foreach (SqlParameter q in cmdParms) { if (q.Direction == ParameterDirection.Output) { indentity = Convert.ToInt32(q.Value); } } cmd.Parameters.Clear(); } trans.Commit(); } catch { trans.Rollback(); throw; } } } } /// <summary> /// 执行多条SQL语句,实现数据库事务。 /// </summary> /// <param name="SQLStringList">SQL语句的哈希表(key为sql语句,value是该语句的SqlParameter[])</param> public static void ExecuteSqlTranWithIndentity(Hashtable SQLStringList) { using (SqlConnection conn = new SqlConnection(connectionString)) { conn.Open(); using (SqlTransaction trans = conn.BeginTransaction()) { SqlCommand cmd = new SqlCommand(); try { int indentity = 0; //循环 foreach (DictionaryEntry myDE in SQLStringList) { string cmdText = myDE.Key.ToString(); SqlParameter[] cmdParms = (SqlParameter[])myDE.Value; foreach (SqlParameter q in cmdParms) { if (q.Direction == ParameterDirection.InputOutput) { q.Value = indentity; } } PrepareCommand(cmd, conn, trans, cmdText, cmdParms); int val = cmd.ExecuteNonQuery(); foreach (SqlParameter q in cmdParms) { if (q.Direction == ParameterDirection.Output) { indentity = Convert.ToInt32(q.Value); } } cmd.Parameters.Clear(); } trans.Commit(); } catch { trans.Rollback(); throw; } } } } /// <summary> /// 执行一条计算查询结果语句,返回查询结果(object)。 /// </summary> /// <param name="SQLString">计算查询结果语句</param> /// <returns>查询结果(object)</returns> public static object GetSingle(string SQLString, params SqlParameter[] cmdParms) { using (SqlConnection connection = new SqlConnection(connectionString)) { using (SqlCommand cmd = new SqlCommand()) { try { PrepareCommand(cmd, connection, null, SQLString, cmdParms); object obj = cmd.ExecuteScalar(); cmd.Parameters.Clear(); if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value))) { return null; } else { return obj; } } catch (Exception e) { Console.WriteLine(e.Message); return null; //throw e; } } } } /// <summary> /// 执行查询语句,返回SqlDataReader ( 注意:调用该方法后,一定要对SqlDataReader进行Close ) /// </summary> /// <param name="strSQL">查询语句</param> /// <returns>SqlDataReader</returns> public static SqlDataReader ExecuteReader(string SQLString, params SqlParameter[] cmdParms) { SqlConnection connection = new SqlConnection(connectionString); SqlCommand cmd = new SqlCommand(); try { PrepareCommand(cmd, connection, null, SQLString, cmdParms); SqlDataReader myReader = cmd.ExecuteReader(CommandBehavior.CloseConnection); cmd.Parameters.Clear(); return myReader; } catch (System.Data.SqlClient.SqlException e) { throw e; } // finally // { // cmd.Dispose(); // connection.Close(); // } } /// <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) { using (SqlConnection connection = new SqlConnection(connectionString)) { SqlCommand cmd = new SqlCommand(); PrepareCommand(cmd, connection, 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 parameter in cmdParms) { if ((parameter.Direction == ParameterDirection.InputOutput || parameter.Direction == ParameterDirection.Input) && (parameter.Value == null)) { parameter.Value = DBNull.Value; } cmd.Parameters.Add(parameter); } } } #endregion #region 存储过程操作 /// <summary> /// 执行存储过程,返回SqlDataReader ( 注意:调用该方法后,一定要对SqlDataReader进行Close ) /// </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) { SqlConnection connection = new SqlConnection(connectionString); SqlDataReader returnReader; connection.Open(); SqlCommand command = BuildQueryCommand(connection, storedProcName, parameters); command.CommandType = CommandType.StoredProcedure; returnReader = command.ExecuteReader(CommandBehavior.CloseConnection); 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) { using (SqlConnection connection = new SqlConnection(connectionString)) { DataSet dataSet = new DataSet(); connection.Open(); SqlDataAdapter sqlDA = new SqlDataAdapter(); sqlDA.SelectCommand = BuildQueryCommand(connection, storedProcName, parameters); sqlDA.Fill(dataSet, tableName); connection.Close(); return dataSet; } } public static DataSet RunProcedure(string storedProcName, IDataParameter[] parameters, string tableName, int Times) { using (SqlConnection connection = new SqlConnection(connectionString)) { DataSet dataSet = new DataSet(); connection.Open(); SqlDataAdapter sqlDA = new SqlDataAdapter(); sqlDA.SelectCommand = BuildQueryCommand(connection, storedProcName, parameters); sqlDA.SelectCommand.CommandTimeout = Times; sqlDA.Fill(dataSet, tableName); connection.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 connection, string storedProcName, IDataParameter[] parameters) { SqlCommand command = new SqlCommand(storedProcName, connection); command.CommandType = CommandType.StoredProcedure; foreach (SqlParameter parameter in parameters) { if (parameter != null) { // 检查未分配值的输出参数,将其分配以DBNull.Value. if ((parameter.Direction == ParameterDirection.InputOutput || parameter.Direction == ParameterDirection.Input) && (parameter.Value == null)) { parameter.Value = DBNull.Value; } 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) { using (SqlConnection connection = new SqlConnection(connectionString)) { int result; connection.Open(); SqlCommand command = BuildIntCommand(connection, storedProcName, parameters); rowsAffected = command.ExecuteNonQuery(); result = (int)command.Parameters["ReturnValue"].Value; //Connection.Close(); return result; } } /// <summary> /// 创建 SqlCommand 对象实例(用来返回一个整数值) /// </summary> /// <param name="storedProcName">存储过程名</param> /// <param name="parameters">存储过程参数</param> /// <returns>SqlCommand 对象实例</returns> private static SqlCommand BuildIntCommand(SqlConnection connection, string storedProcName, IDataParameter[] parameters) { SqlCommand command = BuildQueryCommand(connection, storedProcName, parameters); command.Parameters.Add(new SqlParameter("ReturnValue", SqlDbType.Int, 4, ParameterDirection.ReturnValue, false, 0, 0, string.Empty, DataRowVersion.Default, null)); return command; } #endregion } }
CommandInfo.cs代码:
using System; using System.Collections.Generic; using System.Text; using System.Data.SqlClient; namespace MTBug.sqlHelper { public enum EffentNextType { /// <summary> /// 对其他语句无任何影响 /// </summary> None, /// <summary> /// 当前语句必须为"select count(1) from .."格式,如果存在则继续执行,不存在回滚事务 /// </summary> WhenHaveContine, /// <summary> /// 当前语句必须为"select count(1) from .."格式,如果不存在则继续执行,存在回滚事务 /// </summary> WhenNoHaveContine, /// <summary> /// 当前语句影响到的行数必须大于0,否则回滚事务 /// </summary> ExcuteEffectRows, /// <summary> /// 引发事件-当前语句必须为"select count(1) from .."格式,如果不存在则继续执行,存在回滚事务 /// </summary> SolicitationEvent } public class CommandInfo { public object ShareObject = null; public object OriginalData = null; event EventHandler _solicitationEvent; public event EventHandler SolicitationEvent { add { _solicitationEvent += value; } remove { _solicitationEvent -= value; } } public void OnSolicitationEvent() { if (_solicitationEvent != null) { _solicitationEvent(this, new EventArgs()); } } public string CommandText; public System.Data.Common.DbParameter[] Parameters; public EffentNextType EffentNextType = EffentNextType.None; public CommandInfo() { } public CommandInfo(string sqlText, SqlParameter[] para) { this.CommandText = sqlText; this.Parameters = para; } public CommandInfo(string sqlText, SqlParameter[] para, EffentNextType type) { this.CommandText = sqlText; this.Parameters = para; this.EffentNextType = type; } } }
myHelper.cs代码:
using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Xml; using System.IO; namespace MTBug { public static class myHelper { public delegate void ShowWarnMessage(string _str); public static event ShowWarnMessage showWarnMessage; public static string xmlPath = System.Environment.CurrentDirectory + "\\Resources\\Config.xml"; public static void mySendMessageToMainWindow(string _str) { if (showWarnMessage != null) { showWarnMessage(_str); } } public static string getXMLValue(string eleName) { try { XmlDocument xmlDoc1 = new XmlDocument(); xmlDoc1.Load(xmlPath); var root = xmlDoc1.DocumentElement; XmlNode nodes = xmlDoc1.SelectSingleNode("//" + eleName); if (nodes != null) { xmlDoc1.Save(xmlPath); return nodes.InnerText.ToString(); } else { XmlElement xe1 = xmlDoc1.CreateElement(eleName);//创建一个<hospitalName>节点 xe1.InnerText = ""; root.AppendChild(xe1); xmlDoc1.Save(xmlPath); return ""; } } catch (Exception tt) { myHelper.errorLogAdd(tt.Message); return ""; } } public static void errorLogAdd(string _str) { try { _str = DateTime.Now.ToString("yyyyMMddhhmmss") + "-" + _str; if (System.IO.File.Exists("C://errorLog.txt")) { StreamWriter sw = new StreamWriter("C://errorLog.txt", true, Encoding.GetEncoding("gb2312")); sw.WriteLine(_str); sw.Flush(); sw.Close(); } else { FileStream fs1 = new FileStream("C://errorLog.txt", FileMode.Create, FileAccess.Write);//创建 StreamWriter sw = new StreamWriter(fs1); sw.WriteLine(_str); sw.Flush(); sw.Close(); fs1.Close(); } } catch { } } } }
完成以上步骤之后,在MainWindow.xaml中添加增、删、改三个按钮:
<Canvas x:Name="c_sql" Width="500" Height="150" Canvas.Left="50" Canvas.Top="800" Background="SkyBlue"> <Label x:Name="label1" Height="30" Width="120" Content="数据库SQL更改" FontFamily="Berlin Sans FB" FontSize="16"/> <Button Canvas.Left="50" Canvas.Top="50" Content="添加" Height="60" Name="button1" Width="100" Click="button1_Click" FontSize="20"/> <Button Canvas.Left="200" Canvas.Top="50" Content="删除" Height="60" Name="button2" Width="100" Click="button2_Click" FontSize="20"/> <Button Canvas.Left="350" Canvas.Top="50" Content="更新" Height="60" Name="button3" Width="100" Click="button3_Click" FontSize="20"/> </Canvas>
项目中新建一个类test.cs,代码如下:
using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Data.SqlClient; using System.Data; namespace MTBug.sqlHelper { [Serializable] public partial class test { public test() { } #region Model private int _ids; private string _name; public int ids { set{ _ids = value;} get{ return _ids;} } public string name { set{ _name = value;} get{ return _name;} } #endregion Model #region Model /// <summary> /// 增加一条数据 /// </summary> public int Add(int ids, string username) { ////string _str = "insert into [test] (ids,name) values (" + ids.ToString() + "," + "'"+username.ToString()+"'" + ");"; StringBuilder strSql = new StringBuilder(); strSql.Append("insert into [test] ("); strSql.Append(" ids,name) "); strSql.Append(" values ("); strSql.Append(" @ids,@name)"); SqlParameter[] parameters = { new SqlParameter("@ids", SqlDbType.Int,4), new SqlParameter("@name", SqlDbType.VarChar,20)}; parameters[0].Value = ids; parameters[1].Value = username; //StringBuilder strSql = new StringBuilder(); //strSql.Append("insert into [test] ("); //strSql.Append(" ids,name) values ( "); //strSql.Append("@ids,@name)"); //SqlParameter[] parameters = { // new SqlParameter("@ids", SqlDbType.Int,4), // new SqlParameter("@name", SqlDbType.VarChar,20)}; //parameters[0].Value = ids; //parameters[1].Value = username; object obj = DbHelperSQL.GetSingle(strSql.ToString(), parameters); if (obj == null) { return 0; } else { return Convert.ToInt32(obj); } } /// <summary> /// 删除一条数据 /// </summary> public bool Delete(int ids) { StringBuilder strSql = new StringBuilder(); strSql.Append("delete from [test] "); strSql.Append(" where ids=" + ids.ToString()); int rows = DbHelperSQL.ExecuteSql(strSql.ToString()); if (rows > 0) { return true; } else { return false; } } /// <summary> /// 更新一条数据 /// </summary> public bool Update(int ids, string username) { StringBuilder strSql = new StringBuilder(); strSql.Append("update [test] set "); strSql.Append("name=@name "); strSql.Append(" where ids=@ids "); SqlParameter[] parameters = { new SqlParameter("@ids", SqlDbType.Int,4), new SqlParameter("@name", SqlDbType.VarChar,50)}; parameters[0].Value = ids; parameters[1].Value = username; int rows = DbHelperSQL.ExecuteSql(strSql.ToString(), parameters); if (rows > 0) { return true; } else { return false; } } #endregion Model } }
test代码中定义如何对数据库进行增删改数据的方法。
最后,在MainWindow.xaml.cs后台代码中设置,三个按钮的点击事件:
private void button1_Click(object sender, RoutedEventArgs e) { ///点击往test表里随机插入一条数据 /// test _u = new test(); int _ds = _u.Add(2, "你好"); } private void button2_Click(object sender, RoutedEventArgs e) { test _u = new test(); bool _ds = _u.Delete(2); } private void button3_Click(object sender, RoutedEventArgs e) { test _u = new test(); bool _ds = _u.Update(2, "欧文"); }
查看数据库的表test,数据就可以增删改了。
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出错地点总结:
①增删改数据库的方法类型要与相对应的方法类型一致:
对比:
②传递的参数要对应:
③编写sql语句要正确,尤其字符串要加上,单引号‘’。
例:insert into [MTBugList].[dbo].[test] (ids,name) values (3,'你好');
④有两种C#sql语句的写法:
第一种:
/// <summary> /// 增加一条数据 /// </summary> public int Add(int ids, string username) { string _str = "insert into [test] (ids,name) values (" + ids.ToString() + "," + "'" + username.ToString() + "'" + ");"; object obj = DbHelperSQL.GetSingle(_str.ToString()); if (obj == null) { return 0; } else { return Convert.ToInt32(obj); } }
第二种:
/// <summary> /// 增加一条数据 /// </summary> public int Add(int ids, string username) { StringBuilder strSql = new StringBuilder(); strSql.Append("insert into [test] ("); strSql.Append(" ids,name) "); strSql.Append(" values ("); strSql.Append(" @ids,@name)"); SqlParameter[] parameters = { new SqlParameter("@ids", SqlDbType.Int,4), new SqlParameter("@name", SqlDbType.VarChar,20)}; parameters[0].Value = ids; parameters[1].Value = username; object obj = DbHelperSQL.GetSingle(strSql.ToString(), parameters); if (obj == null) { return 0; } else { return Convert.ToInt32(obj); } }
⑤注意④中含多个字段时,parameters[?].Value要随着更改。
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