I want to make test on a database which is already using by others.
So I came up with the idea that I create a new DB and creates all the tables functions packages from old DB. I made the tests, it's OK to use new DB but I want to switch two DB.
I thought that I could simply change the username after deleting old DB but apparently I cant do that.
Is there an alternative way to change Username In ORACLE DB?
Related
Could you please suggest the easiest way to programmatically (not via UI) generate a script to migrate specific tables (schema, constraints, indexes) to another database on a separate server.
I am aware of replication, SSIS, generate scripts feature, backup-restore approach and SQL Import/export window. However, all these approaches require at least some kind of UI interaction or don' allow to copy constraints or don't allow to migrate only part of data.
Database where I will be putting the data will be in sync with main DB, so it is possible to just wipe-off existing data in it and overwrite with schema and data from main DB.
From Comment: I need to migrate only part of DB: specific tables with their foreign key/primary key constraints, indexes AND data from these tables
as per my understanding i hope this will help you
Click Next
Choose your Location
USE DATABASE: FALSE will help you to execute script in your New DB which you created in your new server basically it will not generate Create DB script
Read carefully Table View/Option whatever you need please make it true
Click Next Pickup script file from your location and run on your new server
We just trying to implement SSDT in our project.
We have lots of clients for one of our products which is built on a single DB (DBDB) with tables and stored procedures only.
We created one SSDT project for database DBDB (using VS 2012 > SQL Server object Browser > right click on project > New Project).
Once we build that project it creates one .sql file.
Problem: if we run that file on client's DBDB - it creates all the tables again & it deletes all records in it [this fulfills the requirements but deletes the existing records :-( ]
What we need: only the update which is not present on the client's DBDB should get update with new changes.
Note : we have no direct access to client's DBDB database for comparing with our latest DBDB. We only can send them some magic script file which will update their DBDB to the latest state.
The only way to update the Client's DB is to compare the DB schemas and then apply the delta. Any way you do it, you will need some way to get a hold on the schema thats running at the client:
IF you ship a versioned product, it is easiest to deploy version N-1 of that to your development server and compare that to the version N you are going to ship. This way, SSDT can generate the migration script you need to ship to the client to pull that DB up to the current schema.
IF you don't have a versioned product, or your client might have altered the schema or you will need to find a way to extract the schema data on site (maybe using SSDT there) and then let SSDT create the delta.
Option: You can skip using the compare feature of SSDT altogether. But then you need to write your migration script yourself. For each modification to the schema, you need to write the DDL statements yourself and wrap them in if clauses that check for the old state so the changes will only be made once and if the old state exists. This way, it doesnt really matter from wich state to wich state you are going as the script will determine for each step if and what to do.
The last is the most flexible, but requires deep testing in its own and of course should have started way before the situation you are in now, where you don't know what the changes have been anymore. But it can help for next time.
This only applies to schema changes on the tables, because you can always fall back to just drop and recreate ALL stored procedures since there is nothing lost in dropping them.
It sounds like you may not be pushing the changes correctly. You have a couple of options if you've built a SQL Project.
Give them the dacpac and have them use SQLPackage to update their own database.
Generate an update script against your customer's "current" version and give that to them.
In any case, it sounds like your publish option might be set to drop and recreate the database each time. I've written quite a few articles on SSDT SQL Projects and getting started that might be helpful here: http://schottsql.blogspot.com/2013/10/all-ssdt-articles.html
I have decided to migrate from my CodeIgniter app to laravel specially for their rails-likely handling of the database.
The problem though is that i have 800mb of database to migrate. How can I do this in a good and fast way? The tutorials i have seen is based on old laravel models to new ones. Which makes me confused.
I also use codeigniter's crypt library for the user passwords. How can I migrate this?
Databases are pretty much the same in Laravel or Codeigniter, if your tables are good the way they are for you and they have a primary key named id (this also is not mandatory) you can just connect with Laravel in your database and it will work just fine.
For your new tables, you can create new migrations and Laravel will not complaint about this.
Well, but if you really need to migrate to a whole new database, you can do the following:
1) rename the tables you need to migrate
php artisan migrate:make
2) create all your migrations with your and migrate them:
php artisan migrate
3) use your database server sql utility to copy data from one table to another, it will be way faster than creating everything in Laravel, believe me. Most databases will let you do things like:
INSERT INTO users (FirstName, LastName)
SELECT FirstName, LastName
FROM users_old
And in some you'll be able to do the same using two different databases and columns names
INSERT INTO NEWdatabasename.users (firstName+' '+Lastname, email)
SELECT name, email
FROM OLDdatabasename.
Or you can just export data to a CSV file and then create a method in your Laravel seeding class to load that data into your database, with a lot of data to import, you just have to remember to execute:
DB::disableQueryLog();
So your PHP doesn't run out of memory.
See? There are a lot of options, probably many more, so pick one and if you need help, shoot more questions.
I am relativley new to MS SQL server. I need to create a test database from exisitng test data base with same schema and get the data from production and fill the newly created empty database. For this I was using generate scripts in SSMS. But now I need to do it on regular basis in a job. Please guide me how I can create empty databases automatically at a point of time.
You will have a very hard time automating the generate scripts wizard. I would suggest using something like Red-Gate's SQL Compare (or any alternative that supports command-line). You can create a new, empty database, then script a compare/deploy using the command line from SQL Server Agent.
Another, more icky alternative, is to deploy your schema and modules to the model database. You can keep this in sync using SQL Compare (or alternatives), or just be diligent about deployment of schema/module changes, then when you create a new database it will automatically inherit the current state of your schema/modules. The problem with this approach (other than depending on you keeping model in sync) is that all new databases will inherit this schema, since there currently is no way to have multiple models.
Have you considered restoring backups?
To add to Aaron's already good answer, I've been using SQLDelta for years - I think it's excellent.
(I have no connection to SqlDelta, other than being a very satisfied customer)
We are in the process of a multi-year project where we're building a new system and a new database to eventually replace the old system and database. The users are using the new and old systems as we're changing them.
The problem we keep running into is when an object in one system is dependent on an object in the other system. We've been using views, but have run into a limitation with one of the technologies (Entity Framework) and are considering other options.
The other option we're looking at right now is replication. My boss isn't excited about the extra maintenance that would cause. So, what other options are there for getting dependent data into the database that needs it?
Update:
The technologies we're using are SQL Server 2008 and Entity Framework. Both databases are within the same sql server instance so linked servers shouldn't be necessary.
The limitation we're facing with Entity Framework is we can't seem to create the relationships between the table-based-entities and the view-based-entities. No relationship can exist in the database between a view and a table, as far as I know, so the edmx diagram can't infer it. And I cannot seem to create the relationship manually without getting errors. It thinks all columns in the view are keys.
If I leave it that way I get an error like this for each column in the view:
Association End key property [...] is
not mapped.
If I try to change the "Entity Key" property to false on the columns that are not the key I get this error:
All the key properties of the
EntitySet [...] must be mapped to all
the key properties [...] of table
viewName.
According to this forum post it sounds like a limitation of the Entity Framework.
Update #2
I should also mention the main limitation of the Entity Framework is that it only supports one database at a time. So we need the old data to appear to be in the new database for the Entity Framework to see it. We only need read access of the old system data in the new system.
You can use linked server queries to leave the data where it is, but connect to it from the other db.
Depending on how up-to-date the data in each db needs to be & if one data source can remain read-only you can:
Use the Database Copy Wizard to create an SSIS package
that you can run periodically as a SQL Agent Task
Use snapshot replication
Create a custom BCP in/out process
to get the data to the other db
Use transactional replication, which
can be near-realtime.
If data needs to be read-write in both database then you can use:
transactional replication with
update subscriptions
merge replication
As you go down the list the amount of work involved in maintaining the solution increases. Using linked server queries will work best if its the right fit for what you're trying to achieve.
EDIT: If they're the same server then as suggested by another user you should be able to access the table with servername.databasename.schema.tablename Looks like it's an entity-framework issues & not a db issue.
I don't know about EntityToSql but I know in LinqToSql you can connect to multiple databases/servers in one .dbml if you prefix the tables with:
ServerName.DatabaseName.SchemaName.TableName
MyServer.MyOldDatabase.dbo.Customers
I have been able to click on a table in the .dbml and copy and paste it into the .dbml of the alternate project prefix the name and set up the relationships and it works... like I said this was in LinqToSql, though have not tried it with EntityToSql. I would give it shot before you go though all the work of replication and such.
If Linq-to-Entities cannot cross DB's then Replication or something that emulates it is the only thing that will work.
For performance purposes you probably want either Merge replication or Transactional with queued (not immediate) updating.
Thanks for the responses. We're going to try adding triggers to the old database tables to insert/update/delete records in the new tables of the new database. This way we can continue to use Entity Framework and also do any data transformations we need.
Once the UI functions move over to the new system for a particular feature, we'll remove the table from the old database and add a view to the old database with the same name that points to the new database table for backwards compatibility.
One thing that I realized needs to happen before we can do this is we have to search all our code and sql for ##Identity and replace it with scope_identity() so the triggers don't mess up the Ids in the old system.