Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers.
Closed 8 years ago.
We don’t allow questions seeking recommendations for books, tools, software libraries, and more. You can edit the question so it can be answered with facts and citations.
Questions asking us to recommend or find a book, tool, software library, tutorial or other off-site resource are off-topic for Stack Overflow as they tend to attract opinionated answers and spam. Instead, describe the problem and what has been done so far to solve it.
Improve this question
I need to know whether there exists any technology to query both SQL Server and Oracle from single application and single query language.
From my limited understanding, and I could be misunderstanding your question, the technology you would use to query both MS SQL Server and Oracle would be:
SQL
...but with different connection strings:
https://www.connectionstrings.com/oracle/
https://connectionstrings.com/sql-server/
T-SQL is the procedural language for SQL Server and Sybase; PL-SQL is Oracle's procedural language.
The two databases have relational theory and SQL in common, but they're very different.
Trying to unify two relational database products into one is a fool's errand.
If i got you correctly you want to develop an application that you can switch databases successfully without much effort. If you are developing using Java you can use Hibernate JPA. It makes it very easy to switch your Application from one database to another with minimal changes and without writing a single sql query. I hope this is what you were looking for.
Hibernate(NHibernate for dotnet) or equivalent is the only choice.
Related
Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers.
We don’t allow questions seeking recommendations for books, tools, software libraries, and more. You can edit the question so it can be answered with facts and citations.
Closed 5 years ago.
Improve this question
I'm coping MySQL databases to Red-Shift with the help of an ETL tool called Matillion, and I'm using the same tool to query the database. Most of the queries I've written are basic select queries with lots of joins, unions and sub-queries.
Since Red-Shift is specialized for analytical processing, I want to transform my basic queries into OLTP queries.
I'll be grateful if someone could point me a direction to learn how to write queries more OLTP way.
Thanks!
To clarify, Redshift is not an OLAP database (like HANA or SSAS), so you can't query Redshift in an OLAP way.
However, Redshift does of course support the full range of analytic functions, which are very much OLAP-like: http://docs.aws.amazon.com/redshift/latest/dg/c_Window_functions.html
Matillion supports that too, for example with the
Window Calculation Component
https://redshiftsupport.matillion.com/customer/portal/articles/1991935-window-calculation-component
You can also search for a Rank Component on the Matillion ETL for Amazon Redshift support portal.
Matillion also has documentation/videos on Data Quality Framework which goes through some of these.
Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers.
Questions asking us to recommend or find a book, tool, software library, tutorial or other off-site resource are off-topic for Stack Overflow as they tend to attract opinionated answers and spam. Instead, describe the problem and what has been done so far to solve it.
Closed 8 years ago.
Improve this question
I know my question sounds a little bit like a shopping request, but I honestly believe that many people could find it useful.
I've been looking for an automatic tool that converts Data Definition Language from MySQL dialect to Oracle dialect - the other way round would also be fine. I found “SQL Fairy” but I was unable to run it; probably because I'm not familiar with PERL.
Is there any free tool for Windows that converts MySQL DDL to Oracle DDL?
This site really worked for me and it can convert a bunch of different DDL commands from Oracle, MySql, M$ Sql Server, Sybase and others. http://www.sqlines.com/online.
Please note the disclaimer below the tool:
Note. SQLines Online is a unrestricted version for EVALUATION USE ONLY. For use in projects, please obtain a license.
Oracle has web pages filled with information on this: Database Migration Technology which gives detailed instrctions and help for several different databases including MySql.
The main tool referenced: Oracle SQL Developer is free.
Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers.
We don’t allow questions seeking recommendations for books, tools, software libraries, and more. You can edit the question so it can be answered with facts and citations.
Closed 4 years ago.
Improve this question
I am writing a database application in C linux. Currently I work on mysql but later we might migrate to postgres. Therefore my boss has asked my to prepare the application to be able to use either of the databases(mysql or postgres).
Is there a free api which I can use for this purpose? Or any suggestion on how best I can do this?
The official answer to that is ODBC.
If you don't like that (and let's face it, no one really does), Qt has a database access module, QtSql. Obviously, this will require you to make heavy use of Qt in your application.
If you can find drivers for your platform, ODBC was supposedly meant to provide exactly this: a platform-independent way to talk to databases.
(I say supposedly because in my experience, ODBC is such a mess that hooking up to an ODBC driver once turned out to be more difficult than just writing the code three times for three different databases.)
Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers.
We don’t allow questions seeking recommendations for books, tools, software libraries, and more. You can edit the question so it can be answered with facts and citations.
Closed 6 years ago.
Improve this question
I have searched the internet for drivers to connect to either database and all the projects I have seen have either been dead for a long time, look incomplete, or don't have good enough documentation to be usable without reading all the source.
Has anyone used Erlang to talk to either MySQL or PostgreSQL before and what sort of package did you use to do this?
Will Glozer wrote a nice native PostgreSQL client:
http://github.com/wg/epgsql
Yariv's mysql driver seems to be the best available: http://code.google.com/p/erlang-mysql-driver/
http://yarivsblog.com/articles/2006/09/13/erlang-mysql-driver-reloaded/
I haven't personally used it as my erlang projects mostly talk to redis, but my quick scan of the source didn't reveal anything too terrifying.
Maturity is a relative thing, especially for more esoteric languages like erlang.
Erlang pgsql - The pgsql-driver is a 100% erlang implementation of the Postgres Frontend/Backend protocol.
Plain straight ODBC ? Quite simple to set it up, but a pain to make it work..
http://github.com/inaka/sumo_db_mysql or http://github.com/inaka/sumo_db_pgsql Both of them are stable, actively maintained and used in production systems
Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers.
We don’t allow questions seeking recommendations for books, tools, software libraries, and more. You can edit the question so it can be answered with facts and citations.
Closed 7 years ago.
Improve this question
I know implementing database is a huge topic, but I want to have a basic understanding of how database systems work (e.g. memory management, binary tree, transaction, sql parsing, multi-threading, partitions, etc) by investigating the source code of the database.
Since there are a few already proven very robust open source databases like mysql, sqlite and so on. However, the code are very complicated and I have no clue where to start. Also I find that the old school database textbooks are only explaining the theory, not the implementation details.
Can anyone suggest how I should get started and if there are any books that emphasis on the technology and techniques of building dbms used in modern database industry?
I hate to sound like an grumpy, old academic, but the theory really is what you need to study, if you are determined to build your own RDBMS. The implementation details are really just, erh, implementation details. Apart from textbooks, you might also want to study research papers, which tend to cover the subject in higher detail.
When you start implementing your database engine, you could look into existing open-source implementations, but do expect the learning curve to be steep. As you have already discovered, these projects tend to be quite complex. When you have concrete questions to those projects, try posting them on the relevant mailinglists. When you have concrete questions about your own implementation, post them here :)
http://en.wikibooks.org/wiki/Design_of_Main_Memory_Database_System
Refer, Database system implementation book by Ullman. Start with jdbc or odbc driver and move down to storage layer if you want to read from code.