******************************************
这是官网新闻左侧类别那部分用到的
****************************************
public string ConnectionString = ConfigurationManager.ConnectionStrings["GsWebDbEntities"].ConnectionString;
public myDBHelper()
{
//
//TODO: 在此处添加构造函数逻辑
//
}
public DataSet ExecuteDataset(CommandType commandType, string commandText, params DbParameter[] commandParameters)
{
if ((this.ConnectionString == null) || (this.ConnectionString.Length == 0))
{
throw new ArgumentNullException("ConnectionString");
}
using (DbConnection connection = new SqlConnection(ConnectionString))
{
connection.ConnectionString = this.ConnectionString;
connection.Open();
return this.ExecuteDataset(connection, commandType, commandText, commandParameters);
}
}
public DataSet ExecuteDataset(DbConnection connection, CommandType commandType, string commandText, params DbParameter[] commandParameters)
{
if (connection == null)
{
throw new ArgumentNullException("connection");
}
DbCommand command = new SqlCommand();
this.PrepareCommand(command, connection, null, commandType, commandText, commandParameters);
using (DbDataAdapter adapter = new SqlDataAdapter())
{
adapter.SelectCommand = command;
DataSet dataSet = new DataSet();
DateTime now = DateTime.Now;
adapter.Fill(dataSet);
DateTime dtEnd = DateTime.Now;
command.Parameters.Clear();
if (connection.State==ConnectionState.Open)
{
connection.Close();
}
return dataSet;
}
}
private void PrepareCommand(DbCommand command, DbConnection connection, DbTransaction transaction, CommandType commandType, string commandText, DbParameter[] commandParameters)
{
if (command == null)
{
throw new ArgumentNullException("command");
}
if ((commandText == null) || (commandText.Length == 0))
{
throw new ArgumentNullException("commandText");
}
if (connection.State != ConnectionState.Open)
{
connection.Open();
}
command.Connection = connection;
command.CommandText = commandText;
if (transaction != null)
{
if (transaction.Connection == null)
{
throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
}
command.Transaction = transaction;
}
command.CommandType = commandType;
if (commandParameters != null)
{
foreach (DbParameter parameter in commandParameters)
{
if (parameter != null)
{
if (((parameter.Direction == ParameterDirection.InputOutput) || (parameter.Direction == ParameterDirection.Input)) && (parameter.Value == null))
{
parameter.Value = DBNull.Value;
}
command.Parameters.Add(parameter);
}
}
}
}
*****************************************************************************以下来自网络,以上来自自己项目中的整理
using
System;
using
System.Data;
using
System.Data.SqlClient;
namespace
DbHelper
{
public
class
SqlDbHelper
{
private
SqlConnection conn;
private
SqlCommand cmd;
private
SqlDataReader reader;
private
SqlDataAdapter adapter;
private
string
connectionString =
@"server=.;database=student;uid=sa;pwd=scce"
;
public
string
ConnectionString
{
get
{
return
this
.connectionString; }
set
{
this
.connectionString = value; }
}
/// <summary>
/// 获取一个未打开连接的SqlConnection对象
/// </summary>
/// <returns>SqlConnection对象</returns>
public
SqlConnection GetConnection()
{
if
(conn !=
null
)
return
this
.conn;
return
this
.conn =
new
SqlConnection(connectionString);
}
/// <summary>
/// 使用连接字符串获取未打开连接SqlConnection对象
/// </summary>
/// <param name="_connStr">连接字符串</param>
/// <returns>SqlConnection对象</returns>
public
SqlConnection GetConnection(
string
_connStr)
{
if
(
this
.conn !=
null
)
this
.conn.ConnectionString = _connStr;
else
this
.conn =
new
SqlConnection(_connStr);
return
this
.conn;
}
/// <summary>
/// 使用指定的Sql语句创建SqlCommand对象
/// </summary>
/// <param name="sqlStr">Sql语句</param>
/// <returns>SqlCommand对象</returns>
private
SqlCommand GetCommand(
string
sqlStr)
{
if
(
this
.conn ==
null
)
this
.conn = GetConnection();
if
(
this
.cmd ==
null
)
this
.cmd =
this
.GetCommand(sqlStr, CommandType.Text,
null
);
else
{
this
.cmd.CommandType = CommandType.Text;
this
.cmd.Parameters.Clear();
}
this
.cmd.CommandText = sqlStr;
return
this
.cmd;
}
/// <summary>
/// 使用指定的Sql语句,CommandType,SqlParameter数组创建SqlCommand对象
/// </summary>
/// <param name="sqlStr">Sql语句</param>
/// <param name="type">命令类型</param>
/// <param name="paras">SqlParameter数组</param>
/// <returns>SqlCommand对象</returns>
public
SqlCommand GetCommand(
string
sqlStr, CommandType type, SqlParameter[] paras)
{
if
(conn ==
null
)
this
.conn =
this
.GetConnection();
if
(cmd ==
null
)
this
.cmd = conn.CreateCommand();
this
.cmd.CommandType = type;
this
.cmd.CommandText = sqlStr;
this
.cmd.Parameters.Clear();
if
(paras !=
null
)
this
.cmd.Parameters.AddRange(paras);
return
this
.cmd;
}
/// <summary>
/// 执行Sql语句返回受影响的行数
/// </summary>
/// <param name="sqlStr">Sql语句</param>
/// <returns>受影响的行数,失败则返回-1</returns>
public
int
ExecuteNoQuery(
string
sqlStr)
{
int
line = -1;
CheckArgs(sqlStr);
try
{ OpenConn(); line =
this
.ExecuteNonQuery(sqlStr,CommandType.Text,
null
); }
catch
(SqlException e) {
throw
e; }
return
line;
}
/// <summary>
/// 使用指定的Sql语句,CommandType,SqlParameter数组执行Sql语句,返回受影响的行数
/// </summary>
/// <param name="sqlStr">Sql语句</param>
/// <param name="type">命令类型</param>
/// <param name="paras">SqlParameter数组</param>
/// <returns>受影响的行数</returns>
public
int
ExecuteNonQuery(
string
sqlStr, CommandType type, SqlParameter[] paras)
{
int
line = -1;
CheckArgs(sqlStr);
if
(
this
.cmd ==
null
)
GetCommand(sqlStr, type, paras);
this
.cmd.Parameters.Clear();
this
.cmd.CommandText = sqlStr;
this
.cmd.CommandType = type;
if
(paras !=
null
)
this
.cmd.Parameters.AddRange(paras);
try
{ OpenConn(); line =
this
.cmd.ExecuteNonQuery(); }
catch
(SqlException e) {
throw
e; }
return
line;
}
/// <summary>
/// 使用指定Sql语句获取dataTable
/// </summary>
/// <param name="sqlStr">Sql语句</param>
/// <returns>DataTable对象</returns>
public
DataTable GetDataTable(
string
sqlStr)
{
CheckArgs(sqlStr);
if
(
this
.conn ==
null
)
this
.conn = GetConnection();
this
.adapter =
new
SqlDataAdapter(sqlStr,
this
.conn);
DataTable table =
new
DataTable();
try
{ adapter.Fill(table); }
catch
(SqlException e) {
throw
e; }
return
table;
}
/// <summary>
/// 使用指定的Sql语句获取SqlDataReader
/// </summary>
/// <param name="sqlStr">sql语句</param>
/// <returns>SqlDataReader对象</returns>
public
SqlDataReader GetSqlDataReader(
string
sqlStr)
{
CheckArgs(sqlStr);
if
(cmd ==
null
)
GetCommand(sqlStr);
if
(reader !=
null
)
reader.Dispose();
try
{ OpenConn();
this
.reader =
this
.cmd.ExecuteReader(); }
catch
(SqlException e) {
throw
e; }
return
this
.reader;
}
/// <summary>
/// 使用事务执行多条Sql语句
/// </summary>
/// <param name="sqlCommands">sql语句数组</param>
/// <returns>全部成功则返回true否则返回false</returns>
public
bool
ExecuteSqls(
string
[] sqlCommands)
{
if
(sqlCommands ==
null
)
throw
new
ArgumentNullException();
if
(
this
.cmd ==
null
)
GetCommand(
null
);
SqlTransaction tran =
null
;
try
{
OpenConn();
tran =
this
.conn.BeginTransaction();
this
.cmd.Transaction = tran;
foreach
(
string
sql
in
sqlCommands)
{
if
(ExecuteNoQuery(sql) == 0)
{ tran.Rollback();
return
false
; }
}
}
catch
(SqlException e)
{
if
(tran !=
null
)
tran.Rollback();
throw
e;
}
tran.Commit();
return
true
;
}
private
void
OpenConn()
{
try
{
if
(
this
.conn.State == ConnectionState.Closed)
conn.Open();
}
catch
(SqlException e) {
throw
e; }
}
private
void
CheckArgs(
string
sqlStr)
{
if
(sqlStr ==
null
)
throw
new
ArgumentNullException();
if
(sqlStr.Length == 0)
throw
new
ArgumentOutOfRangeException();
}
}
}