Relational model

What is a relational database? It is a database that stores the information about both data, for example for a person detail that is link with their car details that they have bought it from the company. The data and relationships are showed in an entity which is in a flat, two dimensional tables. We would use a relational database in a company such as a car company so when they want to store their customers information and what car did they buy, they use a relational database which stores the…

Being and active duty member of the United States Coast Guard, I conduct multi-mission maritime services throughout the globe. I save lives, provide a safe transportation system, protect the environment, enforce laws and protect our national security. Over the years, these services have caused a demand for information system to revolutionize. These advances are needed to analyze and interpret data to coordinate responses to emergencies, track vital information and train personnel. One…

Task 9 COMPARE the usefulness of MySQL and QBE Query by example is a language used for relational databases like SQL. Its development was parallel to that of SQL’s as a database language. It was originally only able to retrieve data from a database, it was then later updated to do other operations like insert, update and delete data from a relational database. It is easier and more productive than SQL as you do not need to remember the finer details of the language as you can easily select…

The benefit of using a relational database is that it can help the efficiency of data storage by avoiding data duplication. It is very easy to change data and the format of it which can be added or removed easily. The data can only be stored once so no more than one record change is needed. Relational databases are used to work together by primary key and foreign key as this creates a link between more than one table. By this it can use the attributes and entities within the database which makes…

The differences in SQL and Relational Algebra are not that many. In fact, they are pretty much the same thing. Both of them have commands that need to be evaluated in order to get a result or a new table. In the SQL, we have commands that need to be followed step by step. For example, the first thing we need to know if we need to join tables. After that, we need to know what columns or fields we are putting as a result, then what table or tables are those columns coming from, and last if there…

based heavily on relational models in which tables are the fundamental building blocks. We may ask the question as to where ER comes in database design, its importance and the need for ER modelling in modern databases. In an attempt to answer these questions, we get to understand that ER is a high-level description of the proposed database, useful for understanding the requirements gathered from a client, in our case The Reproduction Antiques Company. It is a conceptual level data model and…

The rule for first normal form (1NF) is a table in which the intersection of every column and record contains only one value. In other words a table that contains more than one atomic value in the intersection of one or more column for one or more records is not in 1NF. The non 1NF table can be converted to 1NF by restructuring original table by removing the column with the multi-values along with a copy of the primary key to create a new table. See Figure 8.4 for an example of this approach.…

A database object in a relational database is a data structure used to either store or reference data. The most common object that people interact with is the table. Other objects are indexes, stored procedures, sequences, views and many more. When a database object is created, a new object type cannot be created because all the various object types created are restricted by the very nature, or source code, of the relational database model being used, such as Oracle, SQL Server or Access. What…

Caution No blank lines is allowed in the MongoDB Script Sampler. If there is a blank line after MongoDB statement, the statement will still be executed but the word “ok” will be displayed in the response. Add new document into the collection Step 1 Change the “Script” area of the MongoDB Script sampler with insert query. In this case, the query of adding document into the collection is shown as follows: db.getCollection('zips').insert({"city" : "BABYLON", "loc" : [ 32.211100, 44.251500 ],…

Retrieval of data: Objects like Multimedia are very difficult to store, locate and more over this process needs a specialized software which is not available in relational DBMS. Maintenance of data: Conventional relational data are very efficient, but multimedia objects needs to maintain several versions of the data. Meanwhile it treats the whole object as a single part, so whole thing needs to be restored. a) Drivers name, Date of birth date…