在数据库中保存任何文件，只需将其转换为一个字节数组？ [英] Saving any file to in the database, just convert it to a byte array?

问题描述

是一个文件保存任何文件格式到磁盘或数据库VAR二进制列的最佳方式转换为一个字节数组？

Is converting a file to a byte array the best way to save ANY file format to disk or database var binary column?

所以，如果有人要保存一个.gif或.doc / .DOCX或.pdf文件，可我只是将其转换为ByteArray UFT8并将其保存到数据库的字节流？

So if someone wants to save a .gif or .doc/.docx or .pdf file, can I just convert it to a bytearray UFT8 and save it to the db as a stream of bytes?

推荐答案

。以下解决方案适用于2005年和2008年。

Since it's not mentioned what database you mean I'm assuming SQL Server. Below solution works for both 2005 and 2008.

您必须创建 VARBINARY（MAX）表作为列。在我的例子，我创建的表 Raporty 与列 RaportPlik 是 VARBINARY（MAX）列。

You have to create table with VARBINARY(MAX) as one of the columns. In my example I've created Table Raporty with column RaportPlik being VARBINARY(MAX) column.

方法将文件进入从驱动数据库

Method to put file into database from drive:

public static void databaseFilePut(string varFilePath) {
    byte[] file;
    using (var stream = new FileStream(varFilePath, FileMode.Open, FileAccess.Read)) {
        using (var reader = new BinaryReader(stream)) {
            file = reader.ReadBytes((int) stream.Length);       
        }          
    }
    using (var varConnection = Locale.sqlConnectOneTime(Locale.sqlDataConnectionDetails))
    using (var sqlWrite = new SqlCommand("INSERT INTO Raporty (RaportPlik) Values(@File)", varConnection)) {
        sqlWrite.Parameters.Add("@File", SqlDbType.VarBinary, file.Length).Value = file;
        sqlWrite.ExecuteNonQuery();
    }
}

这个方法是从数据库中获取文件，并保存驱动器 于：

This method is to get file from database and save it on drive:

public static void databaseFileRead(string varID, string varPathToNewLocation) {
    using (var varConnection = Locale.sqlConnectOneTime(Locale.sqlDataConnectionDetails))
    using (var sqlQuery = new SqlCommand(@"SELECT [RaportPlik] FROM [dbo].[Raporty] WHERE [RaportID] = @varID", varConnection)) {
        sqlQuery.Parameters.AddWithValue("@varID", varID);
        using (var sqlQueryResult = sqlQuery.ExecuteReader())
            if (sqlQueryResult != null) {
                sqlQueryResult.Read();
                var blob = new Byte[(sqlQueryResult.GetBytes(0, 0, null, 0, int.MaxValue))];
                sqlQueryResult.GetBytes(0, 0, blob, 0, blob.Length);
                using (var fs = new FileStream(varPathToNewLocation, FileMode.Create, FileAccess.Write)) 
                    fs.Write(blob, 0, blob.Length);
            }
    }
}

这个方法是从数据库中获取文件并把它作为的MemoryStream ：

This method is to get file from database and put it as MemoryStream:

public static MemoryStream databaseFileRead(string varID) {
    MemoryStream memoryStream = new MemoryStream();
    using (var varConnection = Locale.sqlConnectOneTime(Locale.sqlDataConnectionDetails))
    using (var sqlQuery = new SqlCommand(@"SELECT [RaportPlik] FROM [dbo].[Raporty] WHERE [RaportID] = @varID", varConnection)) {
        sqlQuery.Parameters.AddWithValue("@varID", varID);
        using (var sqlQueryResult = sqlQuery.ExecuteReader())
            if (sqlQueryResult != null) {
                sqlQueryResult.Read();
                var blob = new Byte[(sqlQueryResult.GetBytes(0, 0, null, 0, int.MaxValue))];
                sqlQueryResult.GetBytes(0, 0, blob, 0, blob.Length);
                //using (var fs = new MemoryStream(memoryStream, FileMode.Create, FileAccess.Write)) {
                memoryStream.Write(blob, 0, blob.Length);
                //}
            }
    }
    return memoryStream;
}

此方法是将的MemoryStream 到数据库：

This method is to put MemoryStream into database:

public static int databaseFilePut(MemoryStream fileToPut) {
        int varID = 0;
        byte[] file = fileToPut.ToArray();
        const string preparedCommand = @"
                    INSERT INTO [dbo].[Raporty]
                               ([RaportPlik])
                         VALUES
                               (@File)
                        SELECT [RaportID] FROM [dbo].[Raporty]
            WHERE [RaportID] = SCOPE_IDENTITY()
                    ";
        using (var varConnection = Locale.sqlConnectOneTime(Locale.sqlDataConnectionDetails))
        using (var sqlWrite = new SqlCommand(preparedCommand, varConnection)) {
            sqlWrite.Parameters.Add("@File", SqlDbType.VarBinary, file.Length).Value = file;

            using (var sqlWriteQuery = sqlWrite.ExecuteReader())
                while (sqlWriteQuery != null && sqlWriteQuery.Read()) {
                    varID = sqlWriteQuery["RaportID"] is int ? (int) sqlWriteQuery["RaportID"] : 0;
                }
        }
        return varID;
    }

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Happy coding :-)

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