I'm currently using SQL Developer 4.5.1.21 and want to take some time to learn language, run queries etc etc. I'm using a database that Oracle provides called "HR Schema" that is free for download. Now I know that I need to create a "connection" in order run queries onto this database. I begin running into trouble when I want to create my own connection. Can anybody walk me through the steps of creating a new connection? What I do is click the "+" button and click "new connection".
The major problem you have here is that you need to have an Oracle database instance installed before you can have something to connect to.
You have a couple of options here...
Download and use the free version of Oracle: Oracle Express Edition
You mentioned that you are a student. Check with your professor to see if they offer a more robust edition of Oracle for student use, such as:
a. Oracle Personal Edition
b. Oracle Standard Edition
c. Oracle Enterprise Edition
If you have the available funds, and you intend on persuing a future in database work, you could purchase a license of one of the above mentioned editions.
You can read more about the various editions of Oracle here.
One thing to keep in mind here is that you are wanting to use the sample schemas that Oracle provides, in particular the "HR" schema. Taking a look at the installation documentation over at the Oracle site, I do not see mention of the Express edition of Oracle server on the availability table, but that may not mean that it wont work.
To address the connection portion of your question, once you get your database set up and running, you should be able to connect to it by providing the hostname (localhost for connecting to your local machine), port, and various other information such as username and password. In all, your connection string would likely look like the following:
Host=localhost; SID=MyOracleServer; port=1677; Min Pool Size=1;
Connection Lifetime=600; User ID=EhBabay; Password=secretpassword123;
Or within SQL Developer you should be able to connect to your local instance of the Oracle database fairly easily, without having to create a connection string. The connection string would still be used though, within any applications you write that you want to connect to the database with.
The main thing here, however is that you need to have an instance of an Oracle database installed and running somewhere that you have access to.
Related
hope everyone are okay...
I need to install any Sofware for the use of SQL. I'm just a begginer and started an online course. We have a account at work called Administrator and the only account has acces to SQL Managment studio 2014. Inside there are multiple databases linked to the external objects for stock contol purposes to collect data and view data, database was created by another company not us. Id like to download an SQL Software to run simple queries. But would need to know if it would affect any other databases or servers inside our network?.. just need to set it up for my local use.
Thanks
I have a MacBook Pro and want to learn more about sql, I understand I cannot run sql from a Mac, what should I install VMware, linux, windows 10? Can someone walk me through this
SQL is just domain specific language (primarily) for relational databases. What you need to decide is what RDBMS, which in turn implements SQL, you would like to use.[1] Standalone implementations like SQLite definitely run on the Mac (many of Apple's own applications like Mail use it as their database.) For the more complex client/server RDBMS systems (i.e. Oracle, SQL Server, MySQL/MariaDB, etc.) you will at least need to install client-side drivers (often in the form of ODBC, JDBC or native drivers) and then either connect to an existing[1] database or install your own database server.
Since it sounds like you're just getting started, I'd highly recommend starting with a standalone database such as SQLite which you should be able to get to by opening a terminal window and typing 'sqlite3' at the prompt. This will allow you to jump right in and focus on learning SQL itself rather than dealing with getting a full-blown client/server database server up and running. (move on to that later if you find it needed/interesting/useful to you)
[1] unless you need to use an existing database, at work for example, in which case you'll need to find out the various details about the server and database in order to connect to it. In this case, you'll need to find a point of contact (often a DBA) to provide this information.
This is my first post in here,
I am new to SQL and I started learning it, I use it mainly in excel to get data from an outer Database
I first go to data then Refresh all then from the menu I choose connection properties
Then a dialogue appears and I input my code in the window called Command text from the Tab Definition
I added images to show where I input my SQL code
My question is what type of SQL do I input there ?
is it mySQL or SQLServer or what ??, so I can learn it, because some commands just don't work with me the way they are supposed to do
You can connect to any database type as long as you have the appropriate ODBC drivers. For example, here is documentation for MySQL for Excel. Quote from article "Use Microsoft Query to retrieve external data":
If the external database that you want to access is not supported by the
ODBC drivers that are installed with Microsoft Query, then you
need to obtain and install a Microsoft Office-compatible ODBC driver
from a third-party vendor, such as the manufacturer of the database.
Contact the database vendor for installation instructions.
OLAP databases do not require ODBC drivers. When you install Microsoft Query, drivers are installed for databases that were created
by using Microsoft SQL Server Analysis Services. To connect to other
OLAP databases, you need to install a data source driver and client
software.
Whichever database type you connect to, you will still be using Microsoft's SQL variant (as developed for SQL Server). As a beginner you're not going to notice too many differences right off the top. Most of the differences are related to data types, such as DATE vs DATETIME. Here is a wiki on SQL Compliance and this article on MS Access SQL will also apply to Excel Query.
You can connect to many data source including: SQL Server database, Access database, MySQL database, PostgreSQL database etc..
You can find the full list here: Link
I understand that this is painfully generic and broad. Nonetheless, all the answers on wikipedia and yahoo (none here that I can find) are pretty useless.
I know T-SQL, C#, etc to some degree. I understand the idea of a database. However, I have NO idea what I created when I made a "server" on my computer through Msft SQL Server. Now I can make databases on that server, and I can connect to them with Visual Studio (sometimes) to use with LINQ or "raw" calls.
Please help me understand (or direct me to an article) of what this myComputerName\SQLEXPRESS (SQL Server xx.x.xxx) thing is. I assume the databases are stored locally...somewhere. SQL Server provides access to the DB files? Why can't they be accessed directly?
Thank you if you even read all this. I really can't narrow the question down.
I guess one specific question is "Can I access the databases without SQL Server running?" Where do I even get the connection string?
You are asking multiple questions, here.
However, I have NO idea what I created when I made a "server" on my
computer through Msft SQL Server. Now I can make databases on that
server, and I can connect to them with Visual Studio (sometimes) to
use with LINQ or "raw" calls.
Please help me understand (or direct me to an article) of what this
myComputerName\SQLEXPRESS (SQL Server xx.x.xxx) thing is.
The layout of a database server is as follows:
Server
Instance a
database aa
database ab
...
Instance b
database ba
database bb
...
...
So, when you install MS SQL Server, you install a MS SQL Server "instance". In this "instance", you can create a number databases. Each database has database files, the exact location of these depends on the settings you chose during installation.
I guess one specific question is "Can I access the databases without
SQL Server running?"
You do not usually open dbf(mdf -ldf) files (the database data files) without MS SQL Server, why would you want to ? You should use the backup/restore features inside MS SQL Server.
Where do I even get the connection string?
http://msdn.microsoft.com/en-us/library/system.data.sqlclient.sqlconnection.connectionstring%28v=vs.110%29.aspx
The "server" is a process/service running on your computer which can be connected to over the network and provides the API to access your database.
"Why can't they be accessed directly?" Is like asking why do I need Word to view Word files, can't I use Notepad for that. Sure you can, but not really.
Another reason is - imagine multiple processes need to access the database. If each reads and writes to the same files, something WILL break if they don't coordinate. Having a separate server process encapsulates all this.
"Can I access the databases without SQL server running?" I mean yes but actually no.
If you want a database that your program accesses directly (or let's say, your program is also the database server in a sense) - then you can use sqlite, or for simple tasks there are also ODBC drivers for CSV, so you can use CSV files as if they were a database. A dedicated SQL server is always better for bigger more complex tasks and data models though.
I have been trying to figure out how to start with Oracle SQL, but I can't get the "Connection" to work. I'm not sure what the (connection name, username, password, etc.) fields are.
If I want to create a small database on local host, why do I need to connect in the first place.
I searched Google but still can't get it to work. Any help is appreciated.
ERROR MESSAGE: IO Error: The Network Adapter could not establish the connection
SQL Developer is just a client utility that lets you connect to an existing database. It sounds like you don't have a database to connect to yet. If that's the case, you'd either need someone to create a database on another machine for you or you'd need to download the database software on to your local machine and create a database to connect to. You can download the Oracle database from the Oracle Technology Network, the same place you downloaded SQL Developer from. I would guess that you would want to download Oracle 11.2 Express Edition.
Alternately, you may want to download one of the VMs that Oracle has put together that has a lot of related software installed for you to use. For example, this VM has SQL Developer, Oracle 12.1, APEX, XML DB, and a number of labs already installed for you.
Oracle SQL Developer is a tool to ACCESS existing database, you cannot create new database here. The connection is used to define where your existing database sits and how to connect to it. So you need to name you connection (bookmark), provide host name, where database runs and user name plus password to identify yourself.