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Best way to retrieve pdf attachments saved as varbinary(max) from SQL Server and save to a local drive using C#

I have few thousands attachments saved in a SQL Server database with column datatype varbinary(max). I want to retrieve all these files and save them to a local drive.
What is the best way to achieve that? I am not looking for code specifically but trying to understand all options so I can do this in C#.
Suggestions are appreciated. Thank you

You can do any of the followings:
Write a SQL script which will read the data from the table and save those to the disk. Here is how that can be done
You can write a C# script which will connect to the Database, Read and store the data as a file to a disk
Use the Id of the table as part of the file name to make it unique if you are storing all the files to a single folder.

Here's example code.
Note, the namespace System.Data.SqlClient is not referenced by a .NET Core project by default as done by .NET Framework; you have to manually add the System.Data.SqlClient NuGet package to the project.
using System.Data.SqlClient;
var connectionString = "Data Source=localhost;Initial Catalog=MyDatbase;Integrated Security=True;";
var outputFolder = #"C:\temp\";
using var conn = new SqlConnection(connectionString);
conn.Open();
var query = "select DocumentId, Contents from DocumentFile where ID >= 1234";
using var cmd = new SqlCommand(query);
cmd.Connection = conn;
var reader = cmd.ExecuteReader();
if (!reader.HasRows) throw new Exception("No rows!");
while (reader.Read())
{
var fileName = $"{reader["DocumentId"]}.pdf";
var data = (byte[])reader["Contents"];
if (data == null) throw new Exception("Contents is null");
using var writer = new BinaryWriter(File.OpenWrite(Path.Combine(outputFolder, fileName)));
writer.Write(data);
}

Visual studio mdf database structure modified then lost after publish

Service-based database is new to me. I would like to create a simple database application with:
Service-based database -> Dataset (mdf)
LINQ to SQL (L2S) Classes
This application will be installed on a lot of individual machines every instances has it's own mdf database.
Installation is done by Clickonce.
My problem is:
I publish my application and install it on user machines
Users put some data into the database
Turns out that we need another table or column
Publish the application again with the extended database and install on user machines
User starts with a new database and original data lost!
(If I am not modifying the database structure than all data is in the database after next Clickone update)
Questions:
If I made only alter table- or add table- like modifications is there any way to preserve data during the next Clickonce update?
Thank you in advance!
Dave

I have found a solution.
If you modify your database model in visual studio Clickonce will automatically recreate all tables after installation (newly published application with modified tables).
Clickonce save the old database to a specified location:
if (ApplicationDeployment.IsNetworkDeployed && ApplicationDeployment.CurrentDeployment.DataDirectory != null)
string preDatabase = Path.GetFullPath(Path.Combine(ApplicationDeployment.CurrentDeployment.DataDirectory,#".pre\sampledatabase.mdf"));
This .pre directory is created by Clickonce. You always check if this file is exist or not. If it is exist you have to copy data from old tables to new tables OR you will loose all data from old tables!
How to copy data from one database to another very similar database? My answer is the following: copy all table to another table with SqlBulkCopy.
// Create source connection
using (
var source =
new SqlConnection(
String.Format(
#"Data Source=(LocalDB)\v11.0;AttachDbFilename={0};Integrated Security=True;",
preDatabase)))
{
source.Open();
// Create destination connection
using (var destination = new SqlConnection(Settings.Default.mdcdbConnectionString))
{
destination.Open();
DataTable dt = source.GetSchema("Tables");
foreach (string tablename in from DataRow row in dt.Rows select (string) row[2])
{
App.Logger.LogText(String.Format("Copying table {0}", tablename));
using (var cmd = new SqlCommand(String.Format("TRUNCATE TABLE {0}", tablename), destination))
{
cmd.ExecuteNonQuery();
//App.Logger.LogText(String.Format("truncate table {0}", tablename));
}
using (var cmd = new SqlCommand(String.Format("SELECT * FROM {0}", tablename), source))
{
using (SqlDataReader reader = cmd.ExecuteReader())
{
var bulkData = new SqlBulkCopy(destination)
{
DestinationTableName = tablename
};
// Set destination table name
bulkData.WriteToServer(reader);
// Close objects
bulkData.Close();
//App.Logger.LogText(String.Format("Copy success {0}", tablename));
}
}
}
destination.Close();
}
source.Close();
}
Wish you good coding!
Dave

Copying table from one SQL Server to another

I'm trying to create a copy of a table (no data, just the schema) using SQL Server Management Objects (SMO), Transfer class. The only thing I haven't figured out is how to specify what server to copy to, when the servers are on different hosts. In my case, I want to copy from 10.1.2.x to 10.1.2.y. Is there any way to specify this, or does this class not support it?
Perhaps there are better C# solutions?
static void CreateTableFromTable(string fromConnection, string toConnection, string dbName, string tablename, bool copyData = false)
{
Server fromServer = new Server(new ServerConnection(new SqlConnection(fromConnection)));
Database db = fromServer.Databases[dbName];
Transfer transfer = new Transfer(db);
transfer.CopyAllObjects = false;
transfer.DropDestinationObjectsFirst = false;
transfer.CopySchema = false; //Database schema? Or Table schema? I DO NOT want to overwrite the db schema
transfer.CopyData = copyData;
transfer.DestinationServer = "?";
transfer.DestinationDatabase = dbName;
transfer.Options.IncludeIfNotExists = true;
transfer.ObjectList.Add(db.Tables[tablename]);
transfer.TransferData();
}

Have you tried import and export data wizard even importing with table data ,command line or GUI in SQL server 2005/8 and Mysql /MysqlWorkbench.

I'm not sure if you found another solution - or got this one working. If you did not the SMO Scripter object might be worth a look.
This MSDN example could be helpful. You could script the tables and dependencies you want and then open a connection to the destination database and execute the scripts.
static void Main(string[] args)
{
Server sourceServer = new Server("server");
String dbName = "database";
// Connect to the local, default instance of SQL Server.
// Reference the database.
Database db = sourceServer.Databases[dbName];
// Define a Scripter object and set the required scripting options.
Scripter scripter = new Scripter(sourceServer);
scripter.Options.ScriptDrops = false;
scripter.Options.WithDependencies = true;
scripter.Options.Indexes = true; // To include indexes
scripter.Options.DriAllConstraints = true; // to include referential constraints in the script
// Iterate through the tables in database and script each one. Display the script.
foreach (Table tb in db.Tables)
{
// check if the table is not a system table
if (tb.IsSystemObject == false)
{
Console.WriteLine("-- Scripting for table " + tb.Name);
// Generating script for table tb
System.Collections.Specialized.StringCollection sc = scripter.Script(new Urn[] { tb.Urn });
foreach (string st in sc)
{
//ado.net to destination
Console.WriteLine(st);//SqlCommand.ExecuteNonQuery();
}
Console.WriteLine("--");
}
}
}

Did you try to use SELECT ... INTO statement?
For example:
SELECT * INTO DestDatabase.TableName FROM SourceDatabase.TableName
If you don't want to copy data, just add a condition which will be return nothing, ex: WHERE Id = 0

System.Data.sqlClient will only create default database on server

Background:
I am using sql statements to create a Temp database on a server which will store data until it is needed further by my client program.
Problem:
My sql statement to create the database works properly and creates the database with all the required specifications when run through Sql Management studio, on the other hand when my program executes the statement it only creates a database with the 'Default' settings except for the name.
Questions:
Why is this?
How can I make it create a database with my specifications
Sql statement:
CREATE DATABASE Temp ON PRIMARY(
NAME = Temp
, FILENAME = 'C:\Temp.mdf'
, SIZE = 2MB
, FILEGROWTH = 10%) LOG ON (
NAME = Temp_Log
, FILENAME = 'C:\Temp.ldf'
, SIZE = 1MB, MAXSIZE = 70MB
, FILEGROWTH = 10%)
Code:
public void AcuConvert()
{
using (DestD)
{
SqlCommand command = new SqlCommand();
DestD.Open();
command.Connection = DestD;
foreach (var item in Entity.SqlDestinationQueries.ToList())
{
command.CommandText = item.Query;
command.ExecuteNonQuery(); //This is where the command is run
}
foreach (var item in Entity.SystemQueries.ToList())
{
command.CommandText = item.Query.Replace("#Sys", SysD.Database);
command.ExecuteNonQuery();
}
foreach (var item in Entity.InsertQueries.ToList())
{
command.CommandText = item.Query.Replace("#Source", SourceD.Database); ;
command.ExecuteNonQuery();
}
}
}

Have you tried using SQL Server Management Objects instead of a raw SQL statement?
For example:
using Microsoft.SqlServer.Management.Smo;
using Microsoft.SqlServer.Management.Common;
...
// Connect to the default instance
Server server = new Server();
// Establish new database details
Database database = new Database(server, "MyTempDB");
// Add primary filegroup details
database.FileGroups.Add(new FileGroup(database, "PRIMARY"));
// Set Primary datafile properties
DataFile primaryFile = new DataFile(database.FileGroups["PRIMARY"],
"MyTempDB_Data", "C:\\MyTempDB.mdf");
primaryFile.Size = 2048; // Sizes are in KB
primaryFile.GrowthType = FileGrowthType.Percent;
primaryFile.Growth = 10;
// Add to the Primary filegroup
database.FileGroups["PRIMARY"].Files.Add(primaryFile);
// Define the log file
LogFile logfile = new LogFile(database, "MyTempDB_Log", "C:\\MyTempDB_Log.ldf");
logfile.Size = 1024;
logfile.GrowthType = FileGrowthType.Percent;
logfile.Growth = 10;
logfile.MaxSize = 70 * 1024;
// Add to the database
database.LogFiles.Add(logfile);
// Create
database.Create();
database.Refresh();
You can connect to the server with specific credentials, too, of course:
http://msdn.microsoft.com/en-us/library/microsoft.sqlserver.management.smo.server.aspx
If, however, you're stuck with using text scripts to create your database, I'd ensure that your Initial Catalog is set correctly (i.e. to 'master') in your connection string and your user has the necessary permissions - CREATE DATABASE / CREATE ANY DATABASE / ALTER DATABASE. If this still doesn't give you any joy, try stripping out the rest of your C# code and run the create SQL independently of the other statements - it could be that there's a side-effect from a preceding query. Use Profiler to see exactly what's running as you add them back in.
Edit:
I tested your script against a local SQL Server instance (2012 SqlLocalDB) via a small C# program using SqlClient and it ran just fine after changing the file paths to ones I had write access to (root of C is protected by default). The only other amendment was that the Primary size had to start at 3MB or more. Any smaller and the default tables could not be created. This may be another avenue of investigation for you to explore.

Your alternative option could be to use the Process class to run the sqlcmd.exe
Eg.
var process = Process.Start(WORKING_PATH, argument);
%WORKING_PATH% being "C:\tools\sql\sqlcmd.exe"
%argument% being "C:\scripts\Create.sql"
I use this strategy to dump test data into test environments when bootstrapping acceptance test fixtures.
Cheers

Passing values to SSIS Connecting string from c#

VS 2008 / SQL 2008
I am importing .csv file to SQL Table.
I want to pass dynamically the Source File and Destination Connection string from C# Code.
For some reasons, this code is working well but package is not executing !!!! How should i pass connection string dynamically from C# code to SSIS Package !!
string strSourceConn = Server.MapPath(filePlacedOrder.Value);
string strDestConn = System.Configuration.ConfigurationManager.AppSettings["SDB"];
string pkgLocation = Server.MapPath("Package.dtsx");
Package pkg;
Microsoft.SqlServer.Dts.Runtime.Application app;
DTSExecResult pkgResults;
app = new Microsoft.SqlServer.Dts.Runtime.Application();
pkg = app.LoadPackage(pkgLocation, null);
pkg.Variables["sConn"].Value = strSourceConn;
pkg.Variables["dConn"].Value = strDestConn;
pkgResults = pkg.Execute();

The best way to dynamically change the connection string is to retrieve the desired connection from the package and then change its connection string. This is different from setting variables with the connection information. In this case you would want to use:
pkg.Connections["sConn"].ConnectionString = strSourceConn;
pkg.Connection["dConn"].ConnectionString = strDestConn;
Where sConn and dConn are the names of the connections in your package.