c# – 将任何文件保存到数据库,只是将其转换为字节数组?

将文件转换为字节数组最好的方式来保存任何文件格式到磁盘或数据库var二进制列?

所以如果有人想要保存一个.gif或.doc / .docx或.pdf文件,我可以把它转换为一个bytearray UFT8并将其保存到db作为字节流?

最佳答案
因为没有提到什么数据库意味着我假设SQL Server。以下解决方案适用于2005年和2008年。

您必须创建具有VARBINARY(MAX)的表作为其中一列。在我的例子中,我创建了Table Raporty,列RaportPlik是VARBINARY(MAX)列。

将文件放入驱动器的数据库的方法:

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();
    }
}

此方法是从数据库获取文件并将其保存在驱动器上:

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获取文件,并将其作为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;
}

这个方法是把MemoryStream放入数据库:

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;
    }

快乐编码:-)

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