OleDb Exception

本文关键字：Exception OleDb | 更新日期: 2023-09-27 17:58:01

经过5个小时的搜索，我找不到我的错误。我得到了这个例外。怎么了？

MyDictionary.exe 中发生类型为"System.Data.OleDb.OleDbException"的未处理异常

附加信息：INSERT INTO语句中存在语法错误。

我的代码：

public void Insert(Word word)
{
    string language=FindLanguage();
    try
    {
        command.CommandText ="INSERT INTO "+language+" ( Native , Foreign , Definition , AddingDate)  values ( '" + word.Native + "' , '" + word.Foreign + "' , '" + word.Definition + "' ,'" + word.AddingDate + "')";
            command.CommandType = System.Data.CommandType.Text;
            connection.Open();
            command.ExecuteNonQuery();
    }
    catch (Exception)
    {
        throw;
    }
    finally
    {
        if (connection != null)
        {
            connection.Close();
        }
    }
}

OleDb Exception

您应该在插入语句中使用参数。看起来您也缺少command.Connection = connection;。请注意，您的SQL容易出现SQL注入

command.CommandText ="INSERT INTO "+language+"([Native],[Foreign],[Definition],[AddingDate]) VALUES (@Native,@Foreign,@Definition,@AddingDate)";
command.Parameters.AddWithValue("@Native", word.Native);
command.Parameters.AddWithValue("@Foreign",word.Foreign);
command.Parameters.AddWithValue("@Definition",word.Definition);
command.Parameters.AddWithValue("@AddingDate",word.AddingDate);
command.CommandType = System.Data.CommandType.Text;
command.Connection = connection;
connection.Open();
command.ExecuteNonQuery();

在OleDb中，INSERT INTO语句的正确语法涉及SELECT子句的使用，即使您正在附加静态值。所以您需要像下面的例子一样更改您的查询。

此外，如果您实际上没有处理引发的异常，则不要构造try...catch..finally。为了便于处理，请改用using() { }块。现在是：

public void Insert(Word word)
{
    string language=FindLanguage();
    using (var connection = new OleDbConnection("connection string goes here"))
    using (var command = new OleDbCommand...)
    {
        command.CommandText = @
            "INSERT INTO " + language + "(Native, Foreign, Definition, AddingDate)" +
            "SELECT '"
                + word.Native + "' AS Native, '" 
                + word.Foreign + "' AS Foreign, '" 
                + word.Definition + "' AS Definition, '"
                + word.AddingDate + "' AS AddingDate"
        ;
        connection.Open();
        command.ExecuteNonQuery();
        connection.Close();
    }
}
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