问题提示:1.阅读器关闭时 Read 的尝试无效。2.未将对象引用设置到对象的实例。3.内部连接致命错误。4.不允许更改“ConnectionString”属性。连接的当前状态为正在连接。
以上错误都会出现。一般运行程序时都没问题就是偶尔来一下。(程序是C#)
错误源码:行 166: catch (Exception e)
行 167: {
行 168: throw new Exception(e.Message); //提示这行有问题
行 169: }
行 170: finally完整源码: /// <summary>
/// 执行Sql查询语句并返回第一行的第一条记录,返回值为object 使用时需要拆箱操作 -> Unbox
/// </summary>
/// <param name="sqlstr">传入的Sql语句</param>
/// <returns>object 返回值 </returns>
public static object ExecuteScalar(string sqlstr)
{
object obj = new object();
SqlCommand comm = new SqlCommand();
try
{
openConnection();
comm.Connection = conn;
comm.CommandType = CommandType.Text;
comm.CommandText = sqlstr;
obj = comm.ExecuteScalar();
}
catch (Exception e)
{
throw new Exception(e.Message);
}
finally
{
comm.Dispose();
closeConnection();
}
return obj;
}
调用的源码: public string Get_SQL_OnlyRecord(string sql)
{
return PS_Conn.ExecuteScalar(sql).ToString();
}
public string Get_Focus_Img()
{
string dataSet = Get_SQL_OnlyRecord("select FocusImg from PS_WebSet where ID = 1");
string FocusList = "\r\n";
int Order = 0;
string[] sArray = Regex.Split(dataSet, ",", RegexOptions.IgnoreCase);
foreach (string i in sArray)
{
Order++;
if (Order <= 4)
{
string BookID = i.ToString();
string BookImg = Get_SQL_OnlyRecord("select BookCover from ps_books where bookid = " + BookID + "");
string BookName = Get_SQL_OnlyRecord("select BookName from ps_books where bookid = " + BookID + "");
string BookIntro = Get_SQL_OnlyRecord("select BookIntro from ps_books where bookid = " + BookID + "");
FocusList += " imgUrl[" + Order + "]='/uploadfiles/" + BookImg + "';\r\n";
FocusList += " imgSUrl[" + Order +"]='/uploadfiles/" + BookImg + "';\r\n";
FocusList += " imgtext[" + Order + "]='<a href=\"/book/" + BookID + "/\">" + BookName + "</a>';\r\n";
FocusList += " imgLink[" + Order + "]='/book/" + BookID + "/';\r\n";
FocusList += " imgAlt[" + Order + "]='" + BookName + "';\r\n";
FocusList += " imgIntro[" + Order + "]='" + PS_Site.Substring(PS_Site.NoAllHTML(BookIntro), 60) + "<a href=\"/book/" + BookID + "/\">[详细]</a>';\r\n";
}
}
return FocusList;
}在上面
string dataSet = Get_SQL_OnlyRecord("select FocusImg from PS_WebSet where ID = 1");
这句读取数据库时有时正确,有时错误。一直找不到原因,请大家帮帮忙!
以上错误都会出现。一般运行程序时都没问题就是偶尔来一下。(程序是C#)
错误源码:行 166: catch (Exception e)
行 167: {
行 168: throw new Exception(e.Message); //提示这行有问题
行 169: }
行 170: finally完整源码: /// <summary>
/// 执行Sql查询语句并返回第一行的第一条记录,返回值为object 使用时需要拆箱操作 -> Unbox
/// </summary>
/// <param name="sqlstr">传入的Sql语句</param>
/// <returns>object 返回值 </returns>
public static object ExecuteScalar(string sqlstr)
{
object obj = new object();
SqlCommand comm = new SqlCommand();
try
{
openConnection();
comm.Connection = conn;
comm.CommandType = CommandType.Text;
comm.CommandText = sqlstr;
obj = comm.ExecuteScalar();
}
catch (Exception e)
{
throw new Exception(e.Message);
}
finally
{
comm.Dispose();
closeConnection();
}
return obj;
}
调用的源码: public string Get_SQL_OnlyRecord(string sql)
{
return PS_Conn.ExecuteScalar(sql).ToString();
}
public string Get_Focus_Img()
{
string dataSet = Get_SQL_OnlyRecord("select FocusImg from PS_WebSet where ID = 1");
string FocusList = "\r\n";
int Order = 0;
string[] sArray = Regex.Split(dataSet, ",", RegexOptions.IgnoreCase);
foreach (string i in sArray)
{
Order++;
if (Order <= 4)
{
string BookID = i.ToString();
string BookImg = Get_SQL_OnlyRecord("select BookCover from ps_books where bookid = " + BookID + "");
string BookName = Get_SQL_OnlyRecord("select BookName from ps_books where bookid = " + BookID + "");
string BookIntro = Get_SQL_OnlyRecord("select BookIntro from ps_books where bookid = " + BookID + "");
FocusList += " imgUrl[" + Order + "]='/uploadfiles/" + BookImg + "';\r\n";
FocusList += " imgSUrl[" + Order +"]='/uploadfiles/" + BookImg + "';\r\n";
FocusList += " imgtext[" + Order + "]='<a href=\"/book/" + BookID + "/\">" + BookName + "</a>';\r\n";
FocusList += " imgLink[" + Order + "]='/book/" + BookID + "/';\r\n";
FocusList += " imgAlt[" + Order + "]='" + BookName + "';\r\n";
FocusList += " imgIntro[" + Order + "]='" + PS_Site.Substring(PS_Site.NoAllHTML(BookIntro), 60) + "<a href=\"/book/" + BookID + "/\">[详细]</a>';\r\n";
}
}
return FocusList;
}在上面
string dataSet = Get_SQL_OnlyRecord("select FocusImg from PS_WebSet where ID = 1");
这句读取数据库时有时正确,有时错误。一直找不到原因,请大家帮帮忙!
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或者
finally
{
comm.Dispose();
closeConnection();
dr.close();
}