C#使用schema.ini导入CSV文件创建表但不加载数据

2022-08-24 08:06:51

我需要将一些CSV文件导入MDB数据库内的临时表中.
这些文件来自ASP.NET Web应用程序上的文件上传.

这是我的CSV文件：

"Operating Unit Organization Name";"Year";"Sales Rep Name";"Date";"Week";"Product Number";"Account Name";"Customer Number";"Corporate Brand";"Brand";"Ordered Quantity";"Amount"
"IT Operating Unit";2014;"Name-561004";2014-02-21;"2014 Week08";"123456+";"Buyer name";"456789";"Corp Brand";"Brand";4;147,52
"IT Operating Unit";2014;"Name-561004";2014-02-21;"2014 Week08";"123.012EXP";"Buyer name";"789123";"Corp Brand";"Brand";10;204,9
"IT Operating Unit";2014;"Name-561004";2014-02-17;"2014 Week08";"101S-3";"Buyer name";"234567";"Another Corp Brand";"Another Brand";30;237,5

这是生成schema.ini文件的方法.由于它必须包含CSV文件的名称,因此每次上载新CSV时,我都会生成一个新的架构文件,因为我需要将它们全部保存在具有特定名称的文件夹中.

private void CreateCsvSchemaFile()
    {
        using (FileStream fs = new FileStream(Path.GetDirectoryName(FilePath) + "\\schema.ini", FileMode.Create, FileAccess.Write))
        {
            using (StreamWriter sw = new StreamWriter(fs))
            {
                sw.WriteLine("[" + Path.GetFileName(FilePath) + "]");
                sw.WriteLine("ColNameHeader=True");
                //sw.WriteLine("MaxScanRows=0");
                sw.WriteLine("Format=Delimited(;)");
                sw.WriteLine("DateTimeFormat=yyyy-MM-dd");
                sw.WriteLine("CharacterSet=ANSI");
                sw.WriteLine("DecimalSymbol=,");
                sw.WriteLine("Col1=\"Operating Unit Organization Name\" Text Width 255");
                sw.WriteLine("Col2=\"Year\" Long");
                sw.WriteLine("Col3=\"Sales Rep Name\" Text Width 255");
                sw.WriteLine("Col4=\"Date\" DateTime");
                sw.WriteLine("Col5=\"Week\" Text Width 255");
                sw.WriteLine("Col6=\"Product Number\" Text Width 255");
                sw.WriteLine("Col7=\"Account Name\" Text Width 255");
                sw.WriteLine("Col8=\"Customer Number\" Text Width 255");
                sw.WriteLine("Col9=\"Corporate Brand\" Text Width 255");
                sw.WriteLine("Col10=\"Brand\" Text Width 255");
                sw.WriteLine("Col11=\"Ordered Quantity\" Long");
                sw.WriteLine("Col12=\"Amount\" Currency");
                sw.Close();
                sw.Dispose();
            }

            fs.Close();
            fs.Dispose();
        }
    }

总会正确生成schema.ini文件,实际上,数据库上的表是使用正确的字段名称和类型创建的.

这是执行CSV导入的方法.

private void ImportCsvIntoTemp()
    {
        try
        {
            CreateCsvSchemaFile();

            string query = @"SELECT * INTO TEMP_CSV 
                                FROM [Text;HDR=no;Database={0}].[{1}]";

            query = String.Format(query, Path.GetDirectoryName(FilePath), Path.GetFileName(FilePath));

            AccessDb.Query(AccessDbConnString, query);
        }
        catch (Exception ex)
        {
            string message = String.Format("CSV file import failed. Inner Exception: {0}", ex.Message);
            throw new ImportFailedException(message);
        }
    }

表TEMP_CSV已正确创建,但没有数据加载到其中.
相反,如果我使用Access打开MDB,则会看到8个空行.我试图更改schema.ini文件上的某些参数,例如添加/删除MaxScnaRows = 0,CharacterSet等…,并且在查询中我也尝试更改FROM属性,但是我总是得到相同的结果.

-编辑添加了AccessDb.Query()方法和数据库连接字符串-

我没有包括Query()方法,因为AccessDb只是一个“数据库层”类,其中包含创建与db的连接并执行带/不带参数的查询/列表查询/标量的方法.我在其他页面和许多其他应用程序中都使用了此类.

无论如何,这是AccessDb.Query()方法.

public static void Query(string connString, string query)
    {
        OleDbConnection conn = new OleDbConnection(connString);

        try
        {
            conn.Open();
            OleDbCommand cmd = conn.CreateCommand();
            cmd.CommandText = query;
            cmd.ExecuteNonQuery();
            cmd.Dispose();
        }
        catch (OleDbException odbEx)
        {
            throw odbEx;
        }
        catch (Exception ex)
        {
            throw ex;
        }
        finally
        {
            conn.Dispose();
            conn.Close();
        }
    }

这是我在Web.config文件中配置的数据库连接字符串.

<connectionStrings>
    <add name="DefaultConnection" providerName="System.Data.OleDb" connectionString="Provider=Microsoft.Jet.OLEDB.4.0;Data Source=D:\Progetti\Personale\Progetti\Infomed\Database\Infomed.mdb;User Id=admin;Password=;" />
</connectionStrings>

解决方法:

您发布的代码本质上是正确的.我将其复制并粘贴到新的C#项目中,并对其进行了足够的调整以使其可以运行.当我确实运行它时,它可以正常工作,创建新表并将所有三(3)行导入其中.

主要区别在于,我仅使用以下代码来执行SELECT * INTO …查询.代替…

AccessDb.Query(AccessDbConnString, query);

…我用了…

using (OleDbConnection con = new OleDbConnection())
{
    con.ConnectionString =
            @"Provider=Microsoft.Jet.OLEDB.4.0;" +
            @"Data Source=C:\Users\Public\test\CsvImportTest\MyDb.mdb;";
    con.Open();
    using (OleDbCommand cmd = new OleDbCommand())
    {
        cmd.Connection = con;
        cmd.CommandText = query;
        cmd.ExecuteNonQuery();
    }
    con.Close();
}

完整的代码是：

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Data.OleDb;

namespace CsvImportTest
{
    class Program
    {
        static string FilePath = @"C:\Users\Public\test\CsvImportTest\TestData.csv";

        static void Main(string[] args)
        {
            ImportCsvIntoTemp();
            Console.WriteLine("Done.");
        }

        private static void ImportCsvIntoTemp()
        {
            try
            {
                CreateCsvSchemaFile();

                string query = @"SELECT * INTO TEMP_CSV 
                                FROM [Text;HDR=no;Database={0}].[{1}]";

                query = String.Format(query, Path.GetDirectoryName(FilePath), Path.GetFileName(FilePath));

                //AccessDb.Query(AccessDbConnString, query);
                using (OleDbConnection con = new OleDbConnection())
                {
                    con.ConnectionString =
                            @"Provider=Microsoft.Jet.OLEDB.4.0;" +
                            @"Data Source=C:\Users\Public\test\CsvImportTest\MyDb.mdb;";
                    con.Open();
                    using (OleDbCommand cmd = new OleDbCommand())
                    {
                        cmd.Connection = con;
                        cmd.CommandText = query;
                        cmd.ExecuteNonQuery();
                    }
                    con.Close();
                }
            }
            catch (Exception ex)
            {
                string message = String.Format("CSV file import failed. Inner Exception: {0}", ex.Message);
                Console.WriteLine(message);
                //throw new ImportFailedException(message);
            }
        }

        private static void CreateCsvSchemaFile()
        {
            using (FileStream fs = new FileStream(Path.GetDirectoryName(FilePath) + "\\schema.ini", FileMode.Create, FileAccess.Write))
            {
                using (StreamWriter sw = new StreamWriter(fs))
                {
                    sw.WriteLine("[" + Path.GetFileName(FilePath) + "]");
                    sw.WriteLine("ColNameHeader=True");
                    //sw.WriteLine("MaxScanRows=0");
                    sw.WriteLine("Format=Delimited(;)");
                    sw.WriteLine("DateTimeFormat=yyyy-MM-dd");
                    sw.WriteLine("CharacterSet=ANSI");
                    sw.WriteLine("DecimalSymbol=,");
                    sw.WriteLine("Col1=\"Operating Unit Organization Name\" Text Width 255");
                    sw.WriteLine("Col2=\"Year\" Long");
                    sw.WriteLine("Col3=\"Sales Rep Name\" Text Width 255");
                    sw.WriteLine("Col4=\"Date\" DateTime");
                    sw.WriteLine("Col5=\"Week\" Text Width 255");
                    sw.WriteLine("Col6=\"Product Number\" Text Width 255");
                    sw.WriteLine("Col7=\"Account Name\" Text Width 255");
                    sw.WriteLine("Col8=\"Customer Number\" Text Width 255");
                    sw.WriteLine("Col9=\"Corporate Brand\" Text Width 255");
                    sw.WriteLine("Col10=\"Brand\" Text Width 255");
                    sw.WriteLine("Col11=\"Ordered Quantity\" Long");
                    sw.WriteLine("Col12=\"Amount\" Currency");
                    sw.Close();
                    sw.Dispose();
                }

                fs.Close();
                fs.Dispose();
            }
        }


    }
}

检查用于实际执行SELECT * INTO …查询的代码,看是否可以发现代码和我的代码之间有显着差异.

码农公寓

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