求SqlConnection,SqlCommand,SqlDataReader和SqlParameter的用法总结

LovePurple 2010-05-17 10:28:51
求上述语句的用法总结 最好结合几个 典型的例子 谢谢了~~~~~~~~~~
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xk1126 2010-05-18
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看msdn网站中微软对每个类的说明吧。
xk1126 2010-05-18
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using System;
using System.Collections.Generic;
using System.Text;
using System.Data;
using System.Data.SqlClient;
using System.Configuration;

namespace MyBookShopDAL
{
public abstract class DBHelper
{
private static readonly string connString =
ConfigurationManager.ConnectionStrings["S2_MyBookShopConnectionString"].ConnectionString;

public static DataSet ExecuteDataSet(string sql)
{
SqlDataAdapter sda = new SqlDataAdapter(sql,connString);
DataSet ds = new DataSet();
sda.Fill(ds,"MySchoolShop");
return ds;
}

public static int ExecuteNonQuery(string sql, CommandType type, params SqlParameter[] ps)
{
SqlConnection connection = new SqlConnection(connString);
SqlCommand command = new SqlCommand(sql,connection);
command.CommandType = type;
if (ps != null)
command.Parameters.AddRange(ps);
connection.Open();
int i = command.ExecuteNonQuery();
connection.Close();
return i;
}


public static SqlDataReader ExecuteDataReader(string sql, CommandType type,params SqlParameter[] ps)
{
SqlConnection connection = new SqlConnection(connString);
SqlCommand command = new SqlCommand(sql, connection);
command.CommandType = type;
if (ps != null)
command.Parameters.AddRange(ps);
connection.Open();
return command.ExecuteReader(CommandBehavior.CloseConnection);
}


public static object ExecuteSalcue(string sql, CommandType type, params SqlParameter[] ps)
{
SqlConnection connection = new SqlConnection(connString);
SqlCommand command = new SqlCommand(sql, connection);
command.CommandType = type;
if (ps != null)
command.Parameters.AddRange(ps);
connection.Open();
object obj = command.ExecuteScalar();
connection.Close();
return obj;
}



}
}

捷哥1999 2010-05-17
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SqlConnection,SqlCommand,SqlReader,SqlDataAdaper 的用法总结!
http://club.topsage.com/thread-513639-1-1.html

看MSDN中对每个类的说明吧。
wangwenzhuang 2010-05-17
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SqlConnection con = new SqlConnection("连接字符串");

// 打开数据库连接
con.Open();

SqlCommand cmd = new SqlCommand("SELECT * FROM 表名 WHERE ID=@ID", con);

// 添加参数
cmd.Parameters.Add(new SqlParameter("@ID", "值"));

// 如果是insert语句,执行ExecuteNonQuery()方法,此方法返回受影响的行数
cmd.ExecuteNonQuery();

// 如果是执行查询返回单个值,执行ExecuteScalar()方法,此方法返回第一行第一列值,返回的是object
cmd.ExecuteScalar();

// 如果执行查询返回多个值
SqlDataReader dr = cmd.ExecuteReader();
// 两种方法读取值

// 1.
DataTable dt = new DataTable();
// 将值读取到DataTable中
dt.Load(dr);

// 2.
while (dr.Read())
{
object a = dr[0];
}

// 关闭sqlDataReader
dr.Close();

// 关闭连接
con.Close();
空心兜兜 2010-05-17
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前来学习
都是照着书弄的
皇城龙三 2010-05-17
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ADO.NET在开发中的部分使用方法和技巧

如何使用 SqlDataAdapter 来检索多个行

以下代码阐明了如何使用 SqlDataAdapter 对象发出可生成 DataSet 或 DataTable 的命令。它从 SQL Server Northwind 数据库中检索一组产品类别。

using System.Data;
using System.Data.SqlClient;

public DataTable RetrieveRowsWithDataTable()
{
using ( SqlConnection conn = new SqlConnection(connectionString) )
{
conn.Open();
SqlCommand cmd = new SqlCommand("DATRetrieveProducts", conn);
cmd.CommandType = CommandType.StoredProcedure;
SqlDataAdapter adapter = new SqlDataAdapter( cmd );
DataTable dataTable = new DataTable("Products");
adapter .Fill(dataTable);
return dataTable;
}
}


....................

详细内容看原文吧,楼主说的基本上都涉及到了

http://www.evget.com/zh-CN/Info/catalog/6438.html
wuyq11 2010-05-17
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ADO.NET编程
看看sqlhelper
using(SqlConnection con=new SqlConnection(""))
{}
public void AddItem(string cartID, int bookID, int quantity) { // 新建Connection和Command对象 SqlConnection myConnection = new SqlConnection(ConfigurationSettings.AppSettings["ConnectionString"]); SqlCommand myCommand = new SqlCommand("ShoppingCartAddItem", myConnection); // 指定命令对象为存储过程 myCommand.CommandType = CommandType.StoredProcedure; // 为存储过程添加参数信息 SqlParameter parameterBookID = new SqlParameter("@BookID", SqlDbType.Int, 4); parameterBookID.Value = bookID; myCommand.Parameters.Add(parameterBookID); SqlParameter parameterCartID = new SqlParameter("@CartID", SqlDbType.NVarChar, 50); parameterCartID.Value = cartID; myCommand.Parameters.Add(parameterCartID); SqlParameter parameterQuantity = new SqlParameter("@Quantity", SqlDbType.Int, 4); parameterQuantity.Value = quantity; myCommand.Parameters.Add(parameterQuantity); // 打开连接并执行操作 myConnection.Open(); myCommand.ExecuteNonQuery(); myConnection.Close(); } /// /// 获取购物车图书总数量 /// /// /// public int GetItemCount(string cartID) { // 新建Connection和Command对象 SqlConnection myConnection = new SqlConnection(ConfigurationSettings.AppSettings["ConnectionString"]); SqlCommand myCommand = new SqlCommand("ShoppingCartItemCount", myConnection); // 指定命令类型为存储过程 myCommand.CommandType = CommandType.StoredProcedure; SqlParameter parameterCartID = new SqlParameter("@CartID", SqlDbType.NVarChar, 50); parameterCartID.Value = cartID; myCommand.Parameters.Add(parameterCartID); // 添加输出参数 SqlParameter parameterItemCount = new SqlParameter("@ItemCount", SqlDbType.Int, 4); //指定参数类型为输出参数 parameterItemCount.Direction = ParameterDirection.Output; myCommand.Parameters.Add(parameterItemCount); // 打开连接并执行操作 myConnection.Open(); myCommand.ExecuteNonQuery(); myConnection.Close(); // 通过存储过程的输出参数来返回购物车总图书量 return ((int)parameterItemCount.Value); } /// /// 根据购物车ID获取购物车信息 /// /// 购物车ID /// DataReader:购物车具体信息 public SqlDataReader GetItems(string cartID) { // 新建Connection和Command实例 SqlConnection myConnection = new SqlConnection(ConfigurationSettings.AppSettings["ConnectionString"]); SqlCommand myCommand = new SqlCommand("ShoppingCartList", myConnection); // 指定命令为存储过程 myCommand.CommandType = CommandType.StoredProcedure; // 添加参数购物车编号到存储过程 SqlParameter parameterCartID = new SqlParameter("@CartID", SqlDbType.NVarChar, 50); parameterCartID.Value = cartID; myCommand.Parameters.Add(parameterCartID); // 打开连接,执行操作 myConnection.Open(); SqlDataReader result = myCommand.ExecuteReader(CommandBehavior.CloseConnection); // 返回数据读取器 return result; } /// /// 获取购物车中图书的总价 /// /// 购物车编号 /// 总价 public decimal GetTotal(string cartID) { // 新建Connection和Command对象 SqlConnection myConnection = new SqlConnection(ConfigurationSettings.AppSettings["ConnectionString"]); SqlCommand myCommand = new SqlCommand("ShoppingCartTotal", myConnection); // 指定命令类型为存储过程 myCommand.CommandType = CommandType.StoredProcedure; // 添加参数到存储过程 SqlParameter parameterCartID = new SqlParameter("@CartID", SqlDbType.NVarChar, 50); parameterCartID.Value = cartID; myCommand.Parameters.Add(parameterCartID); //添加输出总价的参数到存储过程 SqlParameter parameterTotalCost = new SqlParameter("@TotalCost", SqlDbType.Money, 8); parameterTotalCost.Direction = ParameterDirection.Output; myCommand.Parameters.Add(parameterTotalCost); // 打开连接,执行操作 myConnection.Open(); myCommand.ExecuteNonQuery(); myConnection.Close(); // 返回结果 if (parameterTotalCost.Value.ToString() != "") { return (decimal)parameterTotalCost.Value; } else { return 0; } } /// /// 合并购物车:用于合并用户登陆前和登陆后的购物车 /// /// 登陆前的购物车ID /// 登陆后的购物车ID public void MigrateCart(String oldCartId, String newCartId) { // 新建Connection和Command实例 SqlConnection myConnection = new SqlConnection(ConfigurationSettings.AppSettings["ConnectionString"]); SqlCommand myCommand = new SqlCommand("ShoppingCartMigrate", myConnection); // 指定操作类型为存储过程 myCommand.CommandType = CommandType.StoredProcedure; // 添加参数到存储过程 SqlParameter cart1 = new SqlParameter("@OriginalCartId ", SqlDbType.NVarChar, 50); cart1.Value = oldCartId; myCommand.Parameters.Add(cart1); SqlParameter cart2 = new SqlParameter("@NewCartId ", SqlDbType.NVarChar, 50); cart2.Value = newCartId; myCommand.Parameters.Add(cart2); // 打开连接,执行操作 myConnection.Open(); myCommand.ExecuteNonQuery(); myConnection.Close(); } /// /// 删除购物车中的图书 /// /// 购物车编号 /// 图书编号 public void RemoveItem(string cartID, int bookID) { // 新建Connection和Command实例 SqlConnection myConnection = new SqlConnection(ConfigurationSettings.AppSettings["ConnectionString"]); SqlCommand myCommand = new SqlCommand("ShoppingCartRemoveItem", myConnection); // 指定操作类型为存储过程 myCommand.CommandType = CommandType.StoredProcedure; // 添加参数给存储过程 SqlParameter parameterProductID = new SqlParameter("@ProductID", SqlDbType.Int, 4); parameterProductID.Value = bookID; myCommand.Parameters.Add(parameterProductID); SqlParameter parameterCartID = new SqlParameter("@CartID", SqlDbType.NVarChar, 50); parameterCartID.Value = cartID; myCommand.Parameters.Add(parameterCartID); // 打开连接,执行操作 myConnection.Open(); myCommand.ExecuteNonQuery(); myConnection.Close(); } /// /// 更新购物车中图书信息 /// /// 购物车编号 /// 图书编号 /// 图书数量 public void UpdateItem(string cartID, int productID, int quantity) { // 如果输入数量小于0则抛出异常 if (quantity < 0) { throw new Exception("Quantity cannot be a negative number"); } // 新建Connection和Command实例 SqlConnection myConnection = new SqlConnection(ConfigurationSettings.AppSettings["ConnectionString"]); SqlCommand myCommand = new SqlCommand("ShoppingCartUpdate", myConnection); // 指定操作为存储过程 myCommand.CommandType = CommandType.StoredProcedure; // 添加参数给存储过程 SqlParameter parameterProductID = new SqlParameter("@ProductID", SqlDbType.Int, 4); parameterProductID.Value = productID; myCommand.Parameters.Add(parameterProductID); SqlParameter parameterCartID = new SqlParameter("@CartID", SqlDbType.NVarChar, 50); parameterCartID.Value = cartID; myCommand.Parameters.Add(parameterCartID); SqlParameter parameterQuantity = new SqlParameter("@Quantity", SqlDbType.Int, 4); parameterQuantity.Value = quantity; myCommand.Parameters.Add(parameterQuantity); // 打开连接,执行操作 myConnection.Open(); myCommand.ExecuteNonQuery(); myConnection.Close();
using System; using System.Collections; using System.Collections.Generic; using System.Text; using System.Data; using System.Data.SqlClient; using System.Configuration; namespace MyOfficeDAL { public static class DBHelper { private static SqlConnection connection; public static SqlConnection Connection { get { string connectionString = ConfigurationManager.ConnectionStrings["MyOfficeConnectionString"].ConnectionString; connection = new SqlConnection(connectionString); if (connection == null) { connection.Open(); } else if (connection.State == System.Data.ConnectionState.Closed) { connection.Open(); } else if (connection.State == System.Data.ConnectionState.Broken) { connection.Close(); connection.Open(); } return connection; } } public static int ExecuteCommand(string safeSql) { SqlCommand cmd = new SqlCommand(safeSql, Connection); int result = cmd.ExecuteNonQuery(); return result; } public static int ExecuteCommand(string sql, params SqlParameter[] values) { SqlCommand cmd = new SqlCommand(sql, Connection); cmd.Parameters.AddRange(values); return cmd.ExecuteNonQuery(); } public static string ReturnStringScalar(string safeSql) { SqlCommand cmd = new SqlCommand(safeSql, Connection); try { string result = cmd.ExecuteScalar().ToString(); return result; } catch (Exception ex) { return "0"; } connection.Close(); } public static int GetScalar(string safeSql) { SqlCommand cmd = new SqlCommand(safeSql, Connection); try { int result = Convert.ToInt32(cmd.ExecuteScalar()); return result; } catch (Exception e) { return 0; } connection.Close(); } public static int GetScalar(string sql, params SqlParameter[] values) { SqlCommand cmd = new SqlCommand(sql, Connection); cmd.Parameters.AddRange(values); int result = Convert.ToInt32(cmd.ExecuteScalar()); return result; connection.Close(); } public static SqlDataReader GetReader(string safeSql) { SqlCommand cmd = new SqlCommand(safeSql, Connection); SqlDataReader reader = cmd.ExecuteReader(); return reader; reader.Close(); reader.Dispose(); } public static SqlDataReader GetReader(string sql, params SqlParameter[] values) { SqlCommand cmd = new SqlCommand(sql, Connection); cmd.Parameters.AddRange(values); SqlDataReader reader = cmd.ExecuteReader(); return reader; reader.Close(); reader.Dispose(); } public static DataTable GetDataSet(string safeSql) { DataSet ds = new DataSet(); SqlCommand cmd = new SqlCommand(safeSql, Connection); SqlDataAdapter da = new SqlDataAdapter(cmd); da.Fill(ds); connection.Close(); connection.Dispose(); return ds.Tables[0]; } public static DataTable GetDataSet(string sql, params SqlParameter[] values) { DataSet ds = new DataSet(); SqlCommand cmd = new SqlCommand(sql, Connection); cmd.Parameters.AddRange(values); SqlDataAdapter da = new SqlDataAdapter(cmd); da.Fill(ds); connection.Close(); connection.Dispose(); return ds.Tables[0]; } } }
一款特别好用的.net数据库链接通用类。 using System; using System.Collections; using System.Collections.Specialized; using System.Data; using System.Data.SqlClient; using System.Configuration; using System.Data.Common; using System.Collections.Generic; namespace CMS.DBUtility { /// /// 数据访问抽象基础类 /// Copyright (C) 2004-2008 By LiTianPing /// public abstract class DbHelperSQL { //数据库连接字符串(web.config来配置),可以动态更改connectionString支持多数据库. public static string connectionString = PubConstant.ConnectionString; public DbHelperSQL() { } #region 公用方法 /// /// 判断是否存在某表的某个字段 /// /// 表名称 /// 列名称 /// 是否存在 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()); } if (cmdresult == 0) { return false; } else { return true; } } /// /// 表是否存在 /// /// /// 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 /// /// 执行SQL语句,返回影响的记录数 /// /// SQL语句 /// 影响的记录数 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; } } } } /// /// 执行Sql和Oracle滴混合事务 /// /// SQL命令行列表 /// Oracle命令行列表 /// 执行结果 0-由于SQL造成事务失败 -1 由于Oracle造成事务失败 1-整体事务执行成功 public static int ExecuteSqlTran(List list, List oracleCmdSqlList) { using (SqlConnection conn = new SqlConnection(connectionString)) { conn.Open(); SqlCommand cmd = new SqlCommand(); cmd.Connection = conn; SqlTransaction tx = conn.BeginTransaction(); cmd.Transaction = tx; try { foreach (CommandInfo myDE in list) { string cmdText = myDE.CommandText; SqlParameter[] cmdParms = (SqlParameter[])myDE.Parameters; PrepareCommand(cmd, conn, tx, cmdText, cmdParms); if (myDE.EffentNextType == EffentNextType.SolicitationEvent) { if (myDE.CommandText.ToLower().IndexOf("count(") == -1) { tx.Rollback(); throw new Exception("违背要"+myDE.CommandText+"必须符合select count(..的格式"); //return 0; } object obj = cmd.ExecuteScalar(); bool isHave = false; if (obj == null && obj == DBNull.Value) { isHave = false; } isHave = Convert.ToInt32(obj) > 0; if (isHave) { //引发事件 myDE.OnSolicitationEvent(); } } if (myDE.EffentNextType == EffentNextType.WhenHaveContine || myDE.EffentNextType == EffentNextType.WhenNoHaveContine) { if (myDE.CommandText.ToLower().IndexOf("count(") == -1) { tx.Rollback(); throw new Exception("SQL:违背要" + myDE.CommandText + "必须符合select count(..的格式"); //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) { tx.Rollback(); throw new Exception("SQL:违背要" + myDE.CommandText + "返回值必须大于0"); //return 0; } if (myDE.EffentNextType == EffentNextType.WhenNoHaveContine && isHave) { tx.Rollback(); throw new Exception("SQL:违背要" + myDE.CommandText + "返回值必须等于0"); //return 0; } continue; } int val = cmd.ExecuteNonQuery(); if (myDE.EffentNextType == EffentNextType.ExcuteEffectRows && val == 0) { tx.Rollback(); throw new Exception("SQL:违背要" + myDE.CommandText + "必须有影响行"); //return 0; } cmd.Parameters.Clear(); } string oraConnectionString = PubConstant.GetConnectionString("ConnectionStringPPC"); bool res = OracleHelper.ExecuteSqlTran(oraConnectionString, oracleCmdSqlList); if (!res) { tx.Rollback(); throw new Exception("Oracle执行失败"); // return -1; } tx.Commit(); return 1; } catch (System.Data.SqlClient.SqlException e) { tx.Rollback(); throw e; } catch (Exception e) { tx.Rollback(); throw e; } } } /// /// 执行多条SQL语句,实现数据库事务。 /// /// 多条SQL语句 public static int ExecuteSqlTran(List 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; } } } /// /// 执行带一个存储过程参数的的SQL语句。 /// /// SQL语句 /// 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 /// 影响的记录数 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(); } } } /// /// 执行带一个存储过程参数的的SQL语句。 /// /// SQL语句 /// 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 /// 影响的记录数 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(); } } } /// /// 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) /// /// SQL语句 /// 图像字节,数据库的字段类型为image的情况 /// 影响的记录数 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(); } } } /// /// 执行一条计算查询结果语句,返回查询结果(object)。 /// /// 计算查询结果语句 /// 查询结果(object) 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; } } } } /// /// 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 ) /// /// 查询语句 /// SqlDataReader 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; } } /// /// 执行查询语句,返回DataSet /// /// 查询语句 /// DataSet 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 /// /// 执行SQL语句,返回影响的记录数 /// /// SQL语句 /// 影响的记录数 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; } } } } /// /// 执行多条SQL语句,实现数据库事务。 /// /// SQL语句的哈希表(key为sql语句,value是该语句的SqlParameter[]) 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; } } } } /// /// 执行多条SQL语句,实现数据库事务。 /// /// SQL语句的哈希表(key为sql语句,value是该语句的SqlParameter[]) public static int ExecuteSqlTran(System.Collections.Generic.List 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; } } } } /// /// 执行多条SQL语句,实现数据库事务。 /// /// SQL语句的哈希表(key为sql语句,value是该语句的SqlParameter[]) public static void ExecuteSqlTranWithIndentity(System.Collections.Generic.List 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; } } } } /// /// 执行多条SQL语句,实现数据库事务。 /// /// SQL语句的哈希表(key为sql语句,value是该语句的SqlParameter[]) 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; } } } } /// /// 执行一条计算查询结果语句,返回查询结果(object)。 /// /// 计算查询结果语句 /// 查询结果(object) 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 (System.Data.SqlClient.SqlException e) { throw e; } } } } /// /// 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 ) /// /// 查询语句 /// SqlDataReader 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(); // } } /// /// 执行查询语句,返回DataSet /// /// 查询语句 /// DataSet 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 /// /// 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 ) /// /// 存储过程名 /// 存储过程参数 /// SqlDataReader 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; } /// /// 执行存储过程 /// /// 存储过程名 /// 存储过程参数 /// DataSet结果中的表名 /// DataSet 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; } } /// /// 构建 SqlCommand 对象(用来返回一个结果集,而不是一个整数值) /// /// 数据库连接 /// 存储过程名 /// 存储过程参数 /// SqlCommand 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; } /// /// 执行存储过程,返回影响的行数 /// /// 存储过程名 /// 存储过程参数 /// 影响的行数 /// 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; } } /// /// 创建 SqlCommand 对象实例(用来返回一个整数值) /// /// 存储过程名 /// 存储过程参数 /// SqlCommand 对象实例 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 } }
using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Data.SqlClient; using System.Data; namespace 网吧计费系统 { class SqlHelper { static string connStr = "server=.;database=netBarDb;uid=sa;pwd=123456"; //增删改 #region /// /// 执行增删改语句 /// /// insert/delelt/update语句 /// 参数的数组 /// public static int ExecuteNonQuery(string sql, params SqlParameter[] parameters) { //创建连接对象 SqlConnection conn = new SqlConnection(connStr); conn.Open(); //创建命令对象 SqlCommand cmd = new SqlCommand(sql, conn); cmd.Parameters.AddRange(parameters); //返还受影响的行数 int row = cmd.ExecuteNonQuery(); conn.Close(); return row; } #endregion //单行单列查询 #region /// /// 单行单列查询 /// /// select语句 /// 参数数组 /// 第一列第一行的内容 public static object ExecuteScalar(string sql, params SqlParameter[] parameters) { ////创建连接对象 //SqlConnection conn = new SqlConnection(connStr); //conn.Open(); ////创建命令对象 //SqlCommand cmd = new SqlCommand(sql, conn); //cmd.Parameters.AddRange(parameters); //object obj = cmd.ExecuteScalar(); //conn.Close(); //return obj; using (SqlConnection conn = new SqlConnection(connStr)) { conn.Open(); using (SqlCommand cmd = conn.CreateCommand()) { cmd.CommandText = sql; foreach (SqlParameter parameter in parameters) { cmd.Parameters.Add(parameter); } return cmd.ExecuteScalar(); } } } #endregion //多行多列查询 #region /// /// 多行多列连接查询 /// /// select语句 /// 参数数组 /// SqlDataReader读取器 public static SqlDataReader ExecuteReader(string sql, params SqlParameter[] parameters) { SqlConnection conn = new SqlConnection(connStr); conn.Open(); //创建连接对象 SqlCommand cmd = new SqlCommand(sql, conn); cmd.Parameters.AddRange(parameters); SqlDataReader reader = cmd.ExecuteReader(CommandBehavior.CloseConnection

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