C# linq to sql default connection string - linq-to-sql

In an existing C# 2010 application, I want to add linq to sql tatements to connect to a sql server 2008 database. When I setup this linq to sql database, I want to be able to setup the connections to the database using the app.config file.
I have read that when you setup the database connection this way, the default database is used. Basically this is ok when you database on the same database. However, when you move from a unit testing database to a user acceptance and/or a production database there is a problem since the database connection is hard coded in the aqpplication.
Thus can you tell me and/or show me with code how to prevent this problem from occuring?

You must create partial class like This

Related

Creating custom MySQL servers in VB.NET at runtime

I was wondering if it is possible to create custom MySQL servers in VB.NET while working in visual studio at runtime so that if the server already exists it connects and if it isn't there, the code creates the server. I have searched for this everywhere but couldn't find anything. I would appreciate it a lot if someone guides me to the right path.
You could certainly write some .net code to start a MySQL server on your Windows box when an attempt to connect fails. You simply get a cmd.exe console with administrator privileges and give the command net start mysql.
But MySQL must already be installed on the box for that to work.
You might investigate Sqlite. It provides SQL locally to a .net program, storing your tables in a file called whatever.db. It has very similar .net API access to MySQL's Connector/Net and SQL Server's connector. It's in a NuGet package.
I don't completely understand your "custom MySQL servers" requirement. Sqlite gives you a way to use SQL in your application without connecting to a shared server. That may do what you need.
MySQL does have a CREATE SERVER statement in its SQL dialect. The purpose of this statement is to create a connection to another, remote, MySQL server. With that connection you can use the FEDERATED storage engine to access tables in the remote server. Of course, there is no way to run this CREATE SERVER statement unless your program is already connected to a MySQL server.
With respect, your "task which states to create a server at runtime" doesn't make much sense. Is there more to this requirement? What workflow needs this step? Is it part of the installation of some application software on a new box?

SSIS linked to a mySQL server

in SQL server it's possible to link a mySQL server into msSQL and query it using SSMS for example. I want to try this and use SSIS to do some transformations and store all the data on this mySQL database.
\I read that there a several ways to link to mySQL into the msSQL server. OLE DB, mySQL ODBC etc etc.
2 questions:
Are there any limitations i might run into when i will use a combination of SSIS and mySQL instead of msSQL?
When i link a mySQL database into msSQL and i write a query in SSMS, do i write the queries in mySQL language or msSQL language. For example the difference in TOP and LIMIT
I have worked with a linked MySQL Server from SQL Server in the past and ran into some issues.
Querying MySQL from SSMS (SQL Server)
Once you have created a linked server you would imagine you should be able to use the four-part name and query the tables in MySQL but it doesnt allow you. for example you cannot do something like...
Select * from MySqlServer.DbName.Schema.TableName
For some reason it throws an error. So the question whether I can use T-SQL in SSMS to query a Linked MySQL Server? Nope, unfortunately not.
But alternatively Microsoft recommends using OPENQUERY to execute queries to a linked server.
When using OPENQUERY, SQL Server does not try to parse the query, it just sends it to the linked server as it is. which means you can/should be able to write MySQL in SSMS using OPENQUERY and it will work.
Using SSIS with MySQL
Even though SSIS is Microsoft's tool that comes with SQL Server but it is a proper ETL tool which can read data from multiple sources and send data to many types of destination.
Once you have used the appropriate driver to connect to MySQL and ported data in SSIS package , its really not relevant anymore, where the data came from? you would have access to all the SSIS tools and you should be able to use them as if the data was coming from a flat file, SQL Server or Excel sheet etc.
By using Linked Server in MSSQL you can also connect to mySql. for that you need to download ODBC drivers. and then you have to create new dsn and while creating dsn you have to insert mySql server's details. then you can further search regarding how to create Linked server on SQL SERVER. This option is very easy and Totally free. You can use OPEN QUERY FOR inserting, updating, deleting and also get the data out from mySQL.

Transfer sql server data to mysql database using program

I have an old system with sql server database. And I have to create a webiste with mysql database. The old system is still in use and is inserting data to the sql server DB everyday. So, I am thinking write a program that automatically transfer data from the sql server DB to the mysql DB. Any good suggestions? Thanks.
You have an active SQL Server database.
Unless you are planning to decommission this database server (for very good reasons not related to this new application), then the new application should simply query this server.
You can create a small (Maybe in c#) program that keeps running all the times with a timer, and on this timer, get all rows from SQL server that are not marked as "Copied", insert them on MySQL and the update those rows as "Copied". That program need to have access to both databases.

How to load data from MySql to MS SQL Server database?

I have similar schema in both MySQL and MSSQL Server databases. How can I migrate just the data from MySql to an empty (no data) MSSqlServer database? MSSqlServer DB is empty with just the schema. I could not configure the MySql DB as a linked server (through ODBC) since I don't have DB Admin rights on MSSqlServer. I just have previleges to add data. I explored Sql Server Migration Assistant for MySQL, but I just want to migrate data without touching the schema at the target.
I also noticed that there is a SqlBulkCopy class which helps to programatically migrate data in .NET.
But I need to write code for each table (there are more than 100 tables and 20 GB of data).
What is the most elegant way to do it?
SSMA might be the easiest. Since you don't wanna use that, you can try using mysqldump. You can use it to essentially dump a MySQL db to SQL Server.
Link to the SSMA blog, they update these tools regularly, so check for a later version. SQL Server Migration Assistant (SSMA) Team's Blog

What steps are needed to use an Entity Framework model with a MySQL server?

I've added and designed an ADO.NET Entity Data Model (.edmx) and have generated the corresponding DDL Script (.edmx.sql). When I was using SQL Server 2008, all I had to do was connect to it via the Transact-SQL Editor toolbar and execute the SQL. When I try this method, however, it doesn't let me connect to the MySQL server, as it seems to be looking only for Microsoft SQL Servers. I have the latest version of Connector/Net, and can add the MySQL database as a Data Connection, but cannot execute the script I need. What steps are needed to use an Entity Framework model with my MySQL server?
I stumbled across this little property while editing my Data Model:
(This option was installed along side Connector/Net.)
After changing to SSDLToMySQL.tt, right-click and select Generate Database from Model... as you would normally. This will generate the .edmx.sql file, and should give you several errors (as .NET uses SQL Server to parse .sql files.) After generating the DDL script, I opened up MySQL Workbench and pasted the script in. You need to make sure that an appropriately-named schema already exists on the server, then run the script, and voila.