标签: oledbexception

以下代码执行简单的插入命令.如果连续调用2000次(插入2,000行),则抛出一个带有message ="System Resources Exceeded"的OleDbException.还有什么我应该做的事情来释放资源吗？

using (OleDbConnection conn = new OleDbConnection(connectionString))
using (OleDbCommand cmd = new OleDbCommand(commandText, conn))
{
    conn.Open();
    cmd.ExecuteNonQuery();
}

谁能告诉我OleDB连接字符串只是exclusively用于读取其他用户打开的Excel文件？

我试过跟随连接字符串,这对我不起作用: -

"Provider=Microsoft.Jet.OLEDB.4.0;Data Source={0};Mode=Read;Extended Properties=\"Excel 8.0;HDR=YES;ReadOnly=true;\"";

当其他用户打开时,此连接字符串抛出以下异常: -

The Microsoft Jet database engine cannot open the file ''.  It is already opened exclusively by another user, or you need permission to view its data.

笔记:

1. Excel文件保留在共享上,以便多个用户可以打开它.
2. 使用的提供程序: - Microsoft.Jet.OLEDB.4.0
3. Excel文件类型: - MS Excel 97-2003工作表
4. 复制文件时不容许

我有一张桌子上有"SEMESTER,SUBJECT,OFFER,RESULT",其中"SEMESTER"和"SUBJECT"是主要的.当我使用查询

"DELETE FROM Course_Information WHERE Semester = 1 AND Subject = 'CSE-414' ;

它在访问数据库中完美地工作,但是当我尝试在我的c#代码中使用它时,我总是会遇到异常.

此外,如果我使用"DELETE FROM Course_Information WHERE Semester = 1;

我想在WHERE条件下同时使用"SUBJECT"和"SEMESTER"(因为在同一学期可能会有不同的科目)

看我的代码,

connection_string = aConnection.return_connectionString(connection_string);
            string sql_query = "DELETE FROM Course_Information WHERE Semester = " + this.textBox1.Text + " AND Subject = " + this.textBox2.Text + " ;";

            OleDbConnection connect = new OleDbConnection(connection_string);
            OleDbCommand command = new OleDbCommand(sql_query, connect);
            try
            {
                connect.Open();
                OleDbDataReader reader = command.ExecuteReader();
                MessageBox.Show("Delete Successful!");
                connect.Close();
                UpdateDatabase();
            }

            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }

请您检查以下代码是否存在导致"条件表达式中的数据类型不匹配"异常的错误？我似乎无法找到问题的根源......

*record.Date可空DateTime?类型的*被明确地转换为DateTime

*record.Date被设置为可为空,用于程序中的其他用途.但是从DateTimePicker检索INSERT操作的record.Date集合,因此该方法的值永远不应为null.record.Date

哪里

和(如果你想知道的话)

从我的Access文件(设计视图):

谢谢!

这是AddRecord方法.谢谢!

public static int AddRecord(Record record)
{
    OleDbConnection connection = LABMeetingRecordsDB.GetConnection();
    string insertStatement = "INSERT INTO DocumentInfo " +
                             "([FileName], [Date], [Subject], [Type]) " +
                             "VALUES (?, ?, ?, ?)";
    try {
        OleDbCommand insertCommand = new OleDbCommand(insertStatement, connection);
        insertCommand.Parameters.AddWithValue("@FileName", record.FileName);
        insertCommand.Parameters.AddWithValue("@Date", (DateTime)record.Date);
        insertCommand.Parameters.AddWithValue("@Subject", record.Subject);
        insertCommand.Parameters.AddWithValue("@Type", record.getDBType());

        connection.Open();
        insertCommand.ExecuteNonQuery();

        string selectStatement = "SELECT IDENT_CURRENT('DocumentInfo') FROM DocumentInfo"; …

我糊涂了.我正在尝试使用ASP.Net将单个记录添加到Access 2000数据库中.但是,当我尝试添加新记录时,我收到以下错误:

异常详细信息:System.Data.OleDb.OleDbException:操作必须使用可更新的查询.

我无法填写数据 OleDbDataAdapter

我收到OleDbException以下消息 Syntax error in FROM clause.

在这条线上 adapter.Fill(dataset, "User")

这是代码

Imports System.Data.OleDb

Public Class Form1

Public connection As New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=D:\MyDatabase.mdb;Persist Security Info=False")

Private Sub button_display_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles button_display.Click
    connection.Close()
    connection.Open()
    Dim adapter As New OleDbDataAdapter
    adapter.SelectCommand = New OleDbCommand
    adapter.SelectCommand.Connection = connection
    adapter.SelectCommand.CommandText = "select * from user;"

    Dim dataset As New DataSet
    adapter.Fill(dataset, "User")
    connection.Close()
    Dim datarow = dataset.Tables("User").Rows(0)
    Dim fname, lname As String
    fname = datarow(0)
    lname …

Web服务中的以下代码有问题。寻找了解决方案，但是我所看到的似乎与我在下面所做的没什么不同。

注意：字符串变量'AccountNo'被传递到包含以下代码的函数中。

该错误在代码的最后一行-ExecuteReader上生成。

    Dim sConnString As String
    Dim rdr As OleDbDataReader
    Dim orderPaid As Decimal
    Dim fbeused As Decimal

    sConnString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source='c:\orders.mdb'"

    Dim conn As New OleDbConnection(sConnString)

    Dim sb As New StringBuilder
    sb.Append("SELECT DISTINCTROW OrderHeaders.Accountno, Sum(([paidqty]*[unitprice])*[orderheaders].[entpercent]/100) AS orderpaid, Sum([freeqty]*[unitprice]) AS fbeused")
    sb.Append(" FROM OrderHeaders INNER JOIN OrderDetails ON OrderHeaders.[OrderNo] = OrderDetails.[OrderNo]")
    sb.Append(" GROUP BY OrderHeaders.Accountno HAVING OrderHeaders.Accountno=?")
    Dim sqlString As String = sb.ToString

    Dim cmd As New OleDbCommand(sqlString, conn)
    cmd.CommandType = CommandType.Text
    'cmd.Parameters.AddWithValue("AccNo", AccountNo)
    cmd.Parameters.Add("AccNo", OleDbType.VarWChar).Value = AccountNo
    conn.Open() …

我正在使用MS Access数据库.我想获得2个日期之间的第一个和最后一个记录.但是在使用BETWEEN运算符时出错:

查询表达式'Datum_k BETWEEN 3.4.2017中的语法错误数.和3.4.2017.'.

我的代码:

private void GetPrviZadnjiBrojRacuna()
{
    OleDbCommand commandOD = new OleDbCommand("SELECT Dokument FROM DnevniPromet WHERE (Datum_k BETWEEN " + datumOd + " AND " + datumDo + ") ORDER BY [Datum_k] ASC", dataModel.CS);
    OleDbCommand commandDO = new OleDbCommand("SELECT Dokument FROM DnevniPromet WHERE [Datum_k] >= " + datumOd + " AND [Datum_k] <= " + datumDo + " ORDER BY [Datum_k] DESC", dataModel.CS);

    try
    {
        dataModel.DT.Clear();
        OleDbDataAdapter ODbDA = new OleDbDataAdapter(commandOD);

        if (!dataModel.CS.State.Equals(ConnectionState.Open))
        {
            dataModel.CS.Open(); …