What programming languages does SAP HANA support in embedding code to run within the HANA cluster similar to how you would write your own SQL functions to run inside an RDBMS, or your own code to run on a Hadoop cluster.
You basically have two options here. The first thing would be Stored Procedures. These are actually pretty common in other databases like MySQL or DB2. You can create a new procedure with CREATE PROCEDURE. More information on this can be found in the HANA Documentation. The supported languages for this are SQLScript and R.
Another thing that should be mentioned is the XS Engine. Every HANA (I think) has the XS Engine built in. This is basically a JavaScript frontend for your HANA. You can use the XS Engine to write JavaScript APIs, interfaces and applications directly on your HANA using JavaScript. Get started here.
SAP HANA offer XS Engine to integrate and develop apps. Its a good way, considering the network traffic, authentication and security.
The XS Engine is 'server' which allows .html, .css, .js, .csv, images files and .xsjs.
The last one type is a kind of javascript which run as a back-end language, creating connection with database.
Related
In my CS program, I was told I should learn SQL for my databases.
If I'm using PostgreSQL, do I also need a SQL server to go along with it? Is PostgreSQL a language, a server, or both? Is there even a SQL language or is it only servers?
Background: I downloaded Postgres because hey, that has SQL in the name, it works and I'm under the impression it's a pretty good choice anyway. But I couldn't figure out through their website if it needs a companion server, so I went looking for one and found AWS RDS.
The impression I have is that Postgres is the language and AWS RDS is the server, and they serve different functions. But I'm not sure about any of that.
Seems you're learning too many new topics at the same time.
Ok. I'll try to answer.
SQL stands for 'Structured Query Language', and serves as a 'standard' for many vendors that in much ways respects its fundamentals. Oracle, MySQL (now owned by Oracle), MariaDB and PostreSQL are some vendors.
Main thing with SQL code I would recommend you to identify every time you look at it, is to understand if it belongs to DML or DDL. DML stands for 'Data Manipulation Language' and refers to SQL instructions which 'modifies' data. DDL stands for 'Data Declaration Language' which defines or 'alter' de structure on which data will be stored.
Another important concept is atomicity of data manipulation. You can confirm a change or roll it back before it is persisted. This thing corresponds to 'commit' changes or do a 'rollback'. It's some kind of advanced concept, but generally happens "automatically" with standard client configurations. Later, you would have to know about it while programming some system module which interacts with databases.
When you think of the SQL 'server', it refers to the software configured/installed which has the responsability of manage persistence of data within some kind of 'instance' of persistence, allocated in some system with data storage capabilities. AWS implements this service in the cloud, and RDS is the product which supports many kind of SQL flavors to choose (Oracle, Postgresql, etc.)
If you are comfortable with Docker, I recomend you learn the basics which would help you setup and destroy databases many times, which is useful to develop and test locally. Next command, let you start a Postgresql database configured with open port 5432. You can see the server log through docker and use some SQL client to get connected. When you press Ctrl+C everything will be deleted. Of course there are other ways to keep data persistent, but this command would be an easy starting point.
$ docker run --rm -p 5432:5432 --name some-postgres-container-name -e POSTGRES_PASSWORD=mysecretpassword postgres:13.3
Side note: it's better to get used to work with specific docker image versions always (not 'latest').
More details of it usage here: https://hub.docker.com/_/postgres/
if I'm using PostgreSQL, do I also need a SQL server to go along with
it? Is PostgreSQL a language, a server, or both? Is there even a SQL
language or is it only servers lol? I'm genuinely trying to figure
this out myself, but basically everything I read is beyond my scope of
competence and confuses me more. I'm learning the syntax of SQL well
enough, but I'm so confused about everything on the most fundamental
level.
By the way "SQL Server" is Microsoft's SQL flavor, just another one. Don't be confused with the concept of having some SQL server configured.
Yes, you can think of PostgreSQL as a language too, which shares most of its syntax and semantics with other SQL vendors. Yes, there is a 'basic' SQL language shared and compatible between all vendors; some share more aspects than others. In terms of Venn diagrams, you can think of many circles representing each one, Microsoft's SQL Server, Oracle SQL, PostgreSQL, MySQL, etc. sharing the very most of its elements, where each element is a SQL instruction.
When dealing with Databases in general, keep in mind that they helps to modelate situations of 'real world' scenarios or software systems. SQL allows to 'talk' to implementation of "Relational Databases" wich is one kind of database modeling, but there are others too. ER Diagrams helps to represent the 'structure' of a database in a conceptual manner. I like DBeaver because it has an integrated ER diagram generator wich helps to understand the structure of a given database instance.
I have used Postgres and it is an excellent product (and free).
I would install it standalone first. It does come with its own client tools, which you use to communicate with the database server, which runs independently as a service. However, you might be better off installing something like SqlWorkbench as a client tool (which I use). In the config you specify the machine Postgres is running on (which can be your local computer for testing purposes) and the port to connect on. Essentially, the client sends your instructions to Postgres server and the server returns the resultsets associated with your instructions. The client also formats the resultsets into a nice readable "spreadsheet" format with rows and columns.
First I'll try to answer the questions you asked. There is a SQL language, but in practice it is not strictly standardized. There are many offerings for databases and database servers. Many of these are discussed below.
Any database you pick will give you the chance to learn basics of SQL queries and this knowledge will serve you well even if you switch to a different database later.
Specifically, when it comes to PostgreSQL, it is a Relational Database Management System. It is a software that operates as a server. You can install it on your personal computer running Windows, Linux, or MacOS. You can also install in on a dedicated server computer where you'll get better performance and uptime. Further, there are many companies that offer PostgreSQL hosting including Amazon RDS and Google Cloud but they're not free.
For a CS student, PostreSQL installed on your personal computer might be a reasonable choice. But you have lots of options. Read on....
For a CS program, your choice of database will depend on:
what degree of portability you need
how much data you have
how many users will connect to database
what kinds of jobs you might pursue after graduation
Portability
If you think you want to ship your database with your application, then your best bet is probably SQLite. By some accounts it can handle several million rows worth of data and still be performant. However, it's not great if you need for multiple users to connect to the same database. Your data can get corrupted in many multi-user scenarios.
How Much Data and Users
For large data and large users, you'll want to consider the client/server heavy hitters:
PostgreSQL
MySQL/MariaDB
Oracle
SQL Server
These databases will support large quantities of data any many simultaneous connections. But if you want to distribute the database with your application, it's not a good idea. Or if you want to demonstrate your app, you need to ensure that a connection to a server will be available. All of these databases come with a free version, but the last two will have the most restrictions.
After Graduation
Now you're looking to the future and possibly what kind of skills you want to put on your resume. If you think you'll end up in a corporate environment that is already well established, they will likely already have a preferred database and it could be any of the ones listed here (SQLite or the "heavy hitters"). If you want to position yourself as developing apps with low overhead cost, you'll gravitate towards SQLite/PostgreSQL/MySQL. If you think you're going to be some kind of database administrator working in a buttoned-up corporate environment, those companies tend to favor SQL Server and Oracle.
Good luck. Any choice you make will probably be fine. Knowing some flavor of SQL is useful for your future endeavors.
SQL is a language like any other language but working on database. It is called SQL because it works on structured data like table (i.e rows and columns). After reading the documentation of PostgreSQL, I think we do not need any separate server installation. You can download it from here. If you are facing any issues with it I suggest using MySQL workbench. Although installation may take longer time, but its easy to understand.
When I am studying about SAP HANA I come across various SQL terms
Open SQL
Native SQL
SQL script
Can somebody explain which one we use in HANA studio while creating CDS view or scripted calculation view and which SQL we use in our normal ECC program
I am little confused.
We have to start from a bit further
ABAP
Most SAP applications are written in their own programming language, ABAP (some is in java)
Open SQL
When you want to talk to your database in your ABAP program, you have to write SQL. As R3 from SAP works with most relational databases, a common set of features had to be used, with some SAP specific extensions which are translated by the ABAP kernel to be understood by the actual DB. This portable language is called Open SQL.
HAVING and UNION were not allowed for example before 2017, but easy insturctions are added to define where the result is stored.
Native SQL
If you develop for only one database, you can use its native instructions. These can bring additional features or speed, at the cost of transportability.
HANA
For decades SAP did not sell databases, you had to buy one for your ERP system from a third party. A few yeards back SAP started to create its own DB, called HANA.
When you call it from ABAP, you can use Open SQL. If you create a CDS view in HANA Studio, you write Native SQL.
SQLscript
If you want to write stored procedures, you have to use SQLscript, also developed by SAP. With it you have features completely foreign to SQL like loops.
It is just like Transact-SQL for SQL Server, PL/SQL for Oracle, etc - as Eralper wrote
I wonder what are the advantages and disadvantages using one over the other. This question originated from an advice I got here: Allocate buffer dynamically for DB query according to the record actual size
I am looking for a list of the important differences (and not an exhaustive list) that will help me to make an educated decision.
I have working experience with win32::odbc and can testify genuinely about it. It will very helpful if someone can share his/hers experience on top of the ‘dry’ documented details.
Additional info:
The author of Win32::ODBC wrote here: http://www.roth.net/perl/odbc/docs/ODBC_Docs.htm - "There are several alternatives to Win32::ODBC available such as the DataBase Interface (DBI) version called DBD::ODBC. This ODBC Perl extension is available across different platforms such as Mac and UNIX. It is a good tool to use for ODBC access into databases although it lacks some of the functionality that Win32::ODBC has."
I wonder if you know what is the functionality that it lacks.
My main reasons with going for the DBI stack are flexibility and the broader population of testers/debuggers. With DBI you are allowing yourself the option of using a driver that is specifically tuned to your particular database engine. Yes, most databases also offer an ODBC driver, but some specific capabilities may be unavailable or more troublesome through that particular API. Additionally, DBI is platform independent, making any possible future porting to another OS that much less trouble. Lastly the population of folks using DBI for their database access far exceeds those using Win32::ODBC, meaning bugs are likely to be found & patched quicker.
Looking at your other linked question I notice you are using Oracle. Using DBI you'd have the choice between using DBD::ODBC or DBD::Oracle under the hood. You can make this choice with a simple change to one of the parameters of the DBI->connect method.
If you are using Oracle's Instant Client, using DBD::Oracle can save you the trouble of downloading/installing the ODBC component on machines that will only need access via Perl. Of course removing the ODBC layer from the equation may have benefits as well.
Update:
Win32::ODBC is a relatively direct conversion of the ODBC Middleware API from C to Perl. If you are willing to limit yourself to ODBC connections on Windows, this does have the relatively minor advantage of giving you more direct control of the ODBC Middleware layer that is controlling your underlying Database. This of course does not imply that the ODBC API is particularly faithful to the API and/or capabilities of the underlying Database.
Again, presuming that you're using Oracle, you seem to have 3 choices:
Win32::ODBC -> ODBC -> Oracle's Driver for ODBC ~> Oracle Client -> Oracle Server
DBI -> DBD::Oracle ~> Oracle Client -> Oracle Server
DBI -> DBD::ODBC ~> ODBC -> Oracle's Driver for ODBC ~> Oracle Client -> Oracle Server
Where the '~>' is to the right of a layer that needed to "shim" one API to fit another.
Now I can understand if you find API fidelity to the ODBC Middleware to be desirable. Personally, I'd rather have the flexibility of DBI & the shorter software stack used by DBD::Oracle. Though I'll also guess that the longer stack involving DBD::ODBC would suit 99+% of all needs, even with two shim layers.
Another difference between DBI & Win32::ODBC is that there are many modules built around the DBI stack. The entire DBIx namespace depends on it. Search for each of these modules on metacpan.org and click on the 'reverse dependencies' link on their page and you'll get a rather sharp picture of the relative value the Perl community has assigned to each.
So if you want an additional, purely selfish, reason: a Perl developer with experience in DBI will also find themselves in much greater demand. Seriously.
Here comes a simple question but hard to find its answer.
Is there an ABAP Workbench (also known by the transaction code SE80 in SAP R/3) in SAP Business One 2007?
The workbench should be open and not just for SAP use. I would like to know if it's possible to create custom ABAP programs in this SAP solution.
It's not hard to find the answer at all if you bother searching. There is no ABAP Workbench in B1 because B1 is not built on top of the NetWeaver/ABAP stack.
SAP Business One is not built on NetWeaver platform, so there will be no way you can have an ABAP application server. Also, for your information, SBO is not a R/3 Structure .About the technical part in SBO, it has a SQL database and you can only write SQL queries to retrieve data and generate reports. There is a query generator to help you write queries. To conclude, data processing in SBO is very limited comparing to ABAP.
You need to use either .NET/Java for customising or developing screens in SAP Business One.
It doesn't have any relation with ABAP and there are no transaction codes in SAP Business One.
About the technical part in SBO, it has a SQL database and you can only write SQL queries to retrieve data and generate reports. There is a query generator to help you write queries. To conclude, data processing in SBO is very limited comparing to ABAP.
But once you have the data you can do whatever you want with it, for e.g the now native Crystal Report rutime in SBO...Also it has a a pretty rich and mature COM-based SDK for putting data in as well, the DI API (as well as the DI Server which is XML-based). I create solutions for SBO with these all the time in my job...
is there a windows xp utility to make a database such that its support by sql server, oracle, and other db management systems.
the database schema is very huge so i would like to know what to use to make it so its protable from sql server to oracle if future demands that change?
In short, what you seek is nearly impossible to do successfully. Every database product has enough quirks that building such database would not perform well and would be too limiting in terms of the features you were able to use. I.e, you have to play the game of lowest common denominator with respect to features that all products implement you want to support. A far better solution is to abstract the data layer into its own library accessed via interfaces so that you can swap out your data layer. ORMs, as Rafael E. Belliard suggested, makes this simpler but it can also be done manually.
I would recommend building your database using an ORM like Hibernate for Java (or NHibernate for .NET). This would allow you to seamlessly transition from one database type to the other with little to no issues. They would allow you to logically create the database schema without a specific database in mind, which you could then move from one database to the other.
I have created applications which change from SQL Server to MySQL to Oracle to MS Access to SQLite easily (clients love that flexibility).
However, you would need to know your way around programming...