C# DBHelper

这个是一个.NET winforms 中的一个数据库访问类，里面封装了一些访问数据库的方法。

using System;
using System.Collections;
using System.Collections.Specialized;
using System.Data;
using System.Data.SqlClient;
using System.Configuration;

namespace Dream17Logic //可以修改成实际项目的命名空间名称
{
///

/// Copyright (C) 2004-2008 LiTianPing
/// 数据访问基础类(基于SQLServer)
/// 用户可以修改满足自己项目的需要。
///

public abstract class DbHelperSQL
{
//数据库连接字符串(web.config来配置)
//
protected static string connectionString = ConfigurationSettings.AppSettings["ConnectionString"];
public DbHelperSQL()
{
}

#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)
{

throw new Exception(E.Message);
}
finally
{
connection.Close();
}
}
}
}

///

/// 执行多条SQL语句，实现数据库事务。
///

/// 多条SQL语句
public static void ExecuteSqlTran(ArrayList SQLStringList)
{
using (SqlConnection conn = new SqlConnection(connectionString))
{
conn.Open();
SqlCommand cmd = new SqlCommand();
cmd.Connection = conn;
SqlTransaction tx = conn.BeginTransaction();
cmd.Transaction = tx;
try
{
for (int n = 0; n < SQLStringList.Count; n++)
{
string strsql = SQLStringList[n].ToString();
if (strsql.Trim().Length > 1)
{
cmd.CommandText = strsql;
cmd.ExecuteNonQuery();
}
}
tx.Commit();
}
catch (System.Data.SqlClient.SqlException E)
{
tx.Rollback();
throw new Exception(E.Message);
}
}
}
///

/// 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 new Exception(E.Message);
}
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 new Exception(E.Message);
}
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 new Exception(e.Message);
}
}
}
}
///

/// 执行查询语句，返回SqlDataReader
///

/// 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();
return myReader;
}
catch (System.Data.SqlClient.SqlException e)
{
throw new Exception(e.Message);
}

}
///

/// 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;
}
}
///

/// 返回DataTable对象
///

///
///
public static DataTable QueryDataTable(string SQLString)
{
using (SqlConnection connection = new SqlConnection(connectionString))
{
DataTable dt;
DataSet ds = new DataSet();
try
{
connection.Open();
SqlDataAdapter command = new SqlDataAdapter(SQLString, connection);
command.Fill(ds, "ds");
dt = ds.Tables[0];
}
catch (System.Data.SqlClient.SqlException ex)
{
throw new Exception(ex.Message);
}
return dt;
}
}

#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 new Exception(E.Message);
}
}
}
}

///

/// 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 new Exception(e.Message);
}
}
}
}

///

/// 执行查询语句，返回SqlDataReader
///

/// 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();
cmd.Parameters.Clear();
return myReader;
}
catch (System.Data.SqlClient.SqlException e)
{
throw new Exception(e.Message);
}

}

///

/// 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 parm in cmdParms)
cmd.Parameters.Add(parm);
}
}

#endregion

#region 存储过程操作

///

/// 执行存储过程
///

/// 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();
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;
}
}

///

/// 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)
{
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;
}

///

/// 简单防sql注入程序
///

///
///
public static string Sqlstring(string str)
{
str = str.Replace("&", "&");
str = str.Replace("<", "<");
str = str.Replace(">", ">");
str = str.Replace("'", "''");
str = str.Replace("*", "");
str = str.Replace("\n", "
");
str = str.Replace("\r\n", "
");
//str = str.Replace("?","");
str = str.Replace("select", "");
str = str.Replace("insert", "");
str = str.Replace("update", "");
str = str.Replace("delete", "");
str = str.Replace("create", "");
str = str.Replace("drop", "");
str = str.Replace("delcare", "");
str = str.Replace("--", "");
str = str.Replace("@", "");

if (str.Trim().ToString() == "") { str = "null"; }

return str;
}
#endregion

}
}