LibreOffice-Suite-Base/C2/Tables-and-Relationships/English-timed
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Revision as of 09:10, 27 September 2015 by Sandhya.np14 (Talk | contribs)
Time | Narration |
00:00 | Welcome to the Spoken tutorial on LibreOffice Base. |
00:04 | In this tutorial, we will cover Tables and Relationships in LibreOffice Base. |
00:10 | Here, we will learn about: * adding data to a Table. |
00:16 | * Define and create relationships. |
00:19 | In the previous LibreOffice Base tutorial, we introduced Base, database basics and learnt how to create a database and a table. |
00:31 | During the course of the tutorial, we also created an example database called Library and created a 'Books' table as well. |
00:42 | In this tutorial, we will resume with the Library database and learn how to add data to a table. |
00:51 | For this, let us invoke the LibreOffice Base program. |
00:57 | For this, we will click on the Start button at the bottom left of the screen, |
01:03 | click on All programs, then click on LibreOffice Suite and LibreOffice Base. |
01:12 | Since we already created the 'Library' database in the last tutorial, this time we will just need to open it. |
01:21 | To do so, let us click on the open an existing database file option. |
01:28 | In the Recently Used drop-down box, our 'Library' database should be visible. |
01:35 | So now, click on the Finish button. |
01:38 | If you don't see it, we can click on the Open button in the centre to browse to the Windows directory where 'Library database' is saved. |
01:50 | Once found, click on the filename and click on the Open button. |
01:57 | Now, if 'LibreOffice Base' program is already open, we can open the 'Library database' from here. |
02:07 | By clicking on the File menu on the top and then clicking on Open. |
02:14 | We will browse the Windows directory where the 'Library' database file is saved. |
02:21 | Let's click on the file 'Library.odb' and click on the Open button at the bottom. |
02:31 | Now we are in the Library Database. |
02:35 | Let us click on the Tables icon in the Database list on the left panel. |
02:42 | Notice that the Books table appears in the Tables list on the right panel. |
02:48 | Let us now right-click on the Books table. |
02:53 | Notice the various options you can choose from here. |
02:58 | Let us now click on Open to add data to this table. |
03:04 | Alternately, we can also double-click on the table name to open it. |
03:10 | A new window opens with the title 'Books – Library – LibreOffice Base: Table Data View'. |
03:20 | Now we can start entering data into the Books table by typing in values directly into each cell. |
03:31 | Notice the Bookid column has 'AutoField'. |
03:37 | This means Base will assign ascending numbers automatically to each row of data that we insert. |
03:48 | Now, let us input data into the cells, row by row, as shown on the screen. |
04:22 | So, here we have 5 rows of sample data in our table 'Books'. |
04:29 | Let us close the window by clicking the File menu on the top and then choosing Close. |
04:39 | Here is an assignment for you. |
04:42 | Create a Members table that will store information about each member, for example- member name', and phone number. |
04:53 | Include the following three fields. |
04:57 | Member Id with Field type- Integer and make this the primary key. |
05:06 | Name with Fieldtype- Text, |
05:10 | Phone with Fieldtype- Text. |
05:15 | Okay, when you are done, this is how the Members table will look like. |
05:22 | Let us close this window. |
05:25 | Now let us add 4 sample members into the Members table now as shown on the screen , |
05:35 | just the way we did for the Books table. <pause for 10 seconds> |
05:46 | Once done, let us close this window. |
05:50 | Now, let us go back to the main window and click on the Tables Icon again |
05:57 | and let us create the third table: Books Issued. |
06:04 | When done, the Books Issued table will have the following fields: |
06:09 | Issue Id, Field type Integer which will be the primary key, |
06:16 | Book Id, Field type-Integer, |
06:20 | Member Id, Field type-Integer, |
06:24 | Issue Date, Field type- Date, |
06:28 | Return Date, Field type-Date, |
06:31 | Actual Return Date, Field type- Date, |
06:35 | And Checked In, Field type- Yes/No Boolean. |
06:42 | Okay, we have created the Books Issued table. |
06:47 | And now, let us add the following sample data into it as you can see on the screen. |
06:56 | While this may not make absolute sense right now, we will soon understand what’s happening. |
07:17 | Now, we have the three tables in our Library database with sample data also. |
07:25 | Let us now learn about defining relationships in the database. |
07:31 | So, we created three tables to store three different sets of information. |
07:38 | Books, Members and Issue of Books to Members. |
07:44 | Now we also set up columns to uniquely identify each book, each member and each book issued in these three tables. |
07:57 | They are the Primary Keys. |
08:00 | One of the various advantages of a primary key is that it helps to establish relationships between tables. |
08:10 | But why do we need relationships? |
08:13 | Let us look at the Books Issued table. Here, we see the Book-Id and Member-Id fields. |
08:23 | They can have any value in the Books Issued table. |
08:28 | But, they will need to correspond to the same values as we have in the Books and Members tables respectively. |
08:38 | So if the book, Macbeth, has its 'Book Id' as 3 in the 'Books' table |
08:45 | then by using 3 in the 'Book Id' of the 'Books Issued' table, we will still be referring to the same book. |
08:56 | So, to explicitly connect these two tables, we will still need to link them someway. |
09:05 | Also, for example- How will you establish that 'Macbeth' was issued to Ravi Kumar on 2nd June 2011? |
09:16 | Or how will you ensure that a book is issued to only members of the library and not anyone else? |
09:25 | All of these can be achieved by setting up relationships which help interlink the data. |
09:34 | We will need to force Base to use values from the 'Books' table and the 'Members' table only, by linking the appropriate fields. |
09:46 | Let us see how. |
09:48 | In the 'LibreOffice Base' main window, let us click on Tools and then click on Relationships. |
09:58 | This opens a small pop-up window. |
10:03 | Here, we will select the top most table and click on the Add button and repeat for the other two tables also. |
10:15 | Close the pop-up window. |
10:18 | Now we see the three tables Books, Books Issued and Members in a line. |
10:26 | By clicking, dragging and dropping, let us introduce more space among the tables. |
10:35 | Now, let us click on the Book-Id in the Books table and drag and drop it on the Book Id in the Books Issued table. |
10:48 | Notice a line connecting these two field names. So there, we have set up one relationship! |
10:57 | Let us repeat the same for Member-Id. |
11:02 | Click on the Member-Id in the Members table and drag and drop it in the Books Issued table. |
11:11 | You can see that we just created two relationships. |
11:16 | And, this is how we establish relationships |
11:20 | And therefore interlink meaningful data stored in various tables in the relational database. |
11:30 | This brings us to the end of this tutorial on Tables and Relationships in LibreOffice. |
11:36 | To summarize, we learned how to: Add data to a table, Define and create relationships. |
11:45 | Spoken Tutorial project is a part of the Talk to a Teacher project, supported by the National Mission on Education through ICT, MHRD, Government of India. |
11:57 | This project is coordinated by http://spoken-tutorial.org. |
12:03 | More information on the same is available at the following link. |
12:08 | This script has been contributed by Priya Suresh, DesiCrew Solutions. And this is Soundharya, DesiCrew Solutions, signing off.
Thanks for joining. |