4

我从我的 CSV 文件中加载了 83 行，但是当我尝试更新 SQLite 数据库时，我得到 0 行......我不知道我做错了什么。

程序输出： 

Num rows loaded is 83
Num rows updated is 0

源代码是： 

public void InsertData(String csvFileName, String tableName)
{
    String dir = Path.GetDirectoryName(csvFileName);
    String name = Path.GetFileName(csvFileName);

    using (OleDbConnection conn =
        new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" +
        dir + @";Extended Properties=""Text;HDR=Yes;FMT=Delimited"""))
    {
        conn.Open();
        using (OleDbDataAdapter adapter = new OleDbDataAdapter("SELECT * FROM " + name, conn))
        {
            QuoteDataSet ds = new QuoteDataSet();
            adapter.Fill(ds, tableName);
            Console.WriteLine("Num rows loaded is " + ds.Tags.Rows.Count);
            InsertData(ds, tableName);
        }
    }
}

public void InsertData(QuoteDataSet data, String tableName)
{
    using (SQLiteConnection conn = new SQLiteConnection(_connectionString))
    {

        using (SQLiteDataAdapter sqliteAdapter = new SQLiteDataAdapter("SELECT * FROM " + tableName, conn))
        {
            using (new SQLiteCommandBuilder(sqliteAdapter))
            {
                conn.Open();
                Console.WriteLine("Num rows updated is " + sqliteAdapter.Update(data, tableName));
            }
        }
    }
}

关于为什么它没有更新正确的行数的任何提示？

更新：

我试图在调用 update 之前设置命令，但我仍然遇到同样的问题......现在的代码是： 

sqliteAdapter.InsertCommand = cmndBldr.GetInsertCommand();
Console.WriteLine("Num rows updated is " + sqliteAdapter.Update(data, tableName));

当我调试它时，命令文本是：_commandText = "INSERT INTO [Tags] ([tagId], [tagName], [description], [colName], [dataType], [realTime]) VALUES (@param1, @param2, @param3, @param4, @param5, @param6)"

这是一个以 xml 格式显示数据集状态的粘贴图：http: //pastie.org/936882

4

2 回答 2

2

更新：

阅读您的解决方案后，让我说我很尴尬，我没有明白这一点。枚举行以将行状态设置为添加将起作用。

但是让我给你一个更简洁的方法来使用adapter.AcceptChangesDuringFill。

    using (OleDbDataAdapter adapter = new OleDbDataAdapter("SELECT * FROM " + name, conn))
    {
        // this is the proper way to transfer rows
        adapter.AcceptChangesDuringFill = false;

        QuoteDataSet ds = new QuoteDataSet();
        adapter.Fill(ds, tableName);
        Console.WriteLine("Num rows loaded is " + ds.Tags.Rows.Count);
        InsertData(ds, tableName);
    }

这将导入 83 行：

程序.cs

using System;
using System.Data;
using System.Data.SQLite;

namespace SqliteCsv
{
    internal class Program
    {
        private static void Main(string[] args)
        {
            // fill your dataset
            QuoteDataSet ds = new QuoteDataSet();
            ds.ReadXml("data.xml", XmlReadMode.InferTypedSchema);


            // hack to flag each row as new as per lirik
            // OR just set .AcceptChangesDuringFill=false on adapter
            foreach (DataTable table in ds.Tables)
            {
                foreach (DataRow row in table.Rows)
                {
                    row.SetAdded();
                }
            }

            int insertedRows;
            using (
                SQLiteConnection con =
                    new SQLiteConnection(@"data source=C:\Projects\StackOverflowAnswers\SqliteCsv\SqliteCsv\Quotes.db"))
            {
                con.Open();

                // clear table - you may not want this
                SQLiteCommand cmd = con.CreateCommand();
                cmd.CommandText = "delete from Tags";
                cmd.ExecuteNonQuery();


                using (SQLiteTransaction txn = con.BeginTransaction())
                {
                    using (SQLiteDataAdapter dbAdapter = new SQLiteDataAdapter("select * from Tags", con))
                    {
                        dbAdapter.InsertCommand = new SQLiteCommandBuilder(dbAdapter).GetInsertCommand(true);
                        insertedRows = dbAdapter.Update(ds, "Tags");
                    }
                    txn.Commit();
                }
            }
            Console.WriteLine("Inserted {0} rows", insertedRows);

            Console.WriteLine("Press any key");
            Console.ReadKey();
        }
    }
}

原答案：

这是最终被调用的 SQLiteDataAdapter ctor 的来源。请注意，没有使用命令生成器。您需要在 SQLiteDataAdapter 上显式设置 InserCommand 属性，或许可以使用 SQLiteCommandBuilder？

public SQLiteDataAdapter(string commandText, SQLiteConnection connection)
{
    this.SelectCommand = new SQLiteCommand(commandText, connection);
}
于 2010-04-26T04:39:05.283 回答
1

我能够通过遍历每一行并通过调用来改变它的状态来解决这个问题SetAdded();......在我这样做之后，Update 命令就像一个魅力。

public void InsertData(QuoteDataSet dataSet, String tableName)
{
    int numRowsUpdated = 0;
    using (SQLiteConnection conn = new SQLiteConnection(_connectionString))
    {
        conn.Open();
        using (SQLiteTransaction transaction = conn.BeginTransaction())
        using (SQLiteDataAdapter sqliteAdapter = new SQLiteDataAdapter("SELECT * FROM " + tableName, conn))
        {
            using (sqliteAdapter.InsertCommand = new SQLiteCommandBuilder(sqliteAdapter).GetInsertCommand())
            {
                var rows = dataSet.Tags.AsEnumerable();
                foreach (var row in rows)
                {
                    row.SetAdded();
                }
                numRowsUpdated = sqliteAdapter.Update(dataSet, tableName);
            }
            transaction.Commit();
        }
    }
    Console.WriteLine("Num rows updated is " + numRowsUpdated);
}

我假设当DataSet从 CSV 文件中填充，然后我尝试调用Update以将数据插入数据库时​​，该行的状态并不表示任何更改。我们必须告诉DataAdapter它发生了变化，DataSet因为它所看到的只是DataSet它所填充的 CSV 文件没有变化，并且它没有意识到这些是数据库的全新行。我试图把数据放进去。

于 2010-04-28T14:38:56.210 回答