Class 12 Notes Computer Science Using Queries In Access Important Short Questions – In this article, I will give you detailed notes on Unit 3 Database Management Computer Science Class 12. So let’s go!
Every organization is handling data. Keeping and maintaining records is one of the important functions of the organization to promote future trade and business or services.
Class 12 Notes Computer Science Using Queries In Access Important Short Questions
In a record keeping program, entries are made physically in registers. Each entry is entered by a person at the reception. The following steps are considered as inputs to the hospital management system:
Sql Commands Tutorial
Generally a database allows to create, update, delete and retrieve information as needed. Let’s examine an example of a patient information system database.
The pen-and-paper method is difficult to work efficiently and search for documents when needed when these documents are large. So avoiding such difficult tasks should be done by software so that the staff can work well when the patient is admitted or comes to the hospital. This can be done with a file system or a database management system.
File System – Unit 3 Database Management Computer Science Class 12 A file is a device that stores real data and information on a computer that can be stored on a storage device such as text or program code or CSV or image, video, audio, web. pages. file system
Data stored in files can be accessed directly through a special program. So each registry can have different files to store data. The number of records is required as the number of files to store the records and organize the data to work. In addition, there are the following file system limitations:
Bs In Computer Science And Business Administration
Unit 3 Database Management In the next unit of Computer Science Class 12, we are going to discuss the topic of Database Management System.
To overcome the limitations of the file system, a database management system can be used. A database can easily and accurately store, organize and store data.
A database management system refers to software used to create and manage databases. This software allows to create, maintain, manage, update/edit the database and retrieve data from the database as required by the application.
A DBMS provides facilities for extracting data. Abstraction means hiding data. The data is not directly accessible to users. Users must have direct access to programs to access, edit and retrieve stored data. Basically DBMS servers as an interface between database and users.
Pabson Class 10 Computer Science Solution
Retrieving data from a database in a DBMS requires a specific type of command. Users can change/modify the database itself using different commands.
Let us understand the different application areas of DBMS in this article Unit 3 Database Management Computer Science Class 12 The application areas of DBMS are as follows:
We have seen that different files can be created in the file system but cannot be linked together. While the DBMS allows them to be linked or joined using common fields.
For example, we have two files: doctor and patient. The doctor table has a doctor_id field that contains a unique ID for each doctor working in the hospital. If a doctor handles a patient’s case, that patient can be assigned a doctor using this doctor_id. So common field for all is doctor_id and then data can be fetched from all tables. So when a patient is admitted to the hospital it can be added to the room and bill table using the patient_id.
Cbse Class 12 Computer Science Syllabus 2022 2023 (pdf): Check Course Structure With Scheme Of Theory & Practical Examination
Data Models A data model refers to the description of the structure of a database. A database describes how a database can be created and used.
Now let’s see some words related to data model Unit 3 Database Management for Computer Science Class 12
Among the data models, the most popular data model is the relational data model. Let’s discuss some terms related to the relational data model.
A relation refers to a database table in the relational data model. A relation consists of records (rows or tuples) and fields (columns or values). A record represents a set of values. Colon names must be unique.
Unit 3 Database Management Computer Science Class 12
The values are columns or fields in the table. Columns are attributes or parameters for which data can be stored in a table.
Each row of the table is called a tuple or record. In a table with n columns, a tuple is a relation between n related elements.
The set of values from each attribute takes a value for each row. To define data for a region, a data type can be defined.
Keys in a relational database represent restrictions or constraints on attribute values and objects that are related to each other. Keys are defined when defining a database through keys. These keys are:
Ncert Solutions Class 12 Computer Science Python Free Pdf Download
Now in the next part of Unit 3 Database Management Computer Science Class 12, we are going to discuss another topic Structured Query Language.
Unit 3 Database Management In the next unit of Computer Science Class 12, we are going to discuss MySQL data types.
Each structure in the database has a data type. The data type represents what type of data will be entered in the column. The data type can be defined row wise.
Sometimes calculations can be shown in columns. Therefore, choosing the right data type for relational attributes is a must. Let’s talk about some of the commonly used data types available in MySQL. This is how we do it!
C++ Practical Bifurcation
It is used to specify character-length parameters. n represents a number of characters from 0 to 255. A fixed-length means that specifying 10 characters will consume 10 character spaces in the field.
It is used to define a variable-length character data type from 0 to 65535. Variable-length means to declare 10 characters, 10 characters can be stored but the actual given characters will be placed in the column. It needs space according to the value entered in the row.
It is used to specify a whole number without decimal places. It takes 4 bytes from 0 to 4, 294, 967, 295. For larger values, BIGINT can be used, which takes 8 bytes.
Dates are stored in the ‘YYYY/MM/DD’ format, where YYYY is the four-digit year, MM is the two-digit month and DD is the two-digit date. Dates range from ‘1000-01-01’ to ‘9999-12-31’.
Computer Science (python) 2018 2019 Cbse (science) Class 12 Set 4 Question Paper With Pdf Download
A column that represents the value of an attribute defined as the primary key in another table.
Now in the next part of Unit 3 Database Management Computer Science Class 12 we will talk about SQL for defining data. This is how we do it!
After creating the database you need to open the database using the utility command. Initially, the database is empty. You can check it using the following command:
Since the database is empty it shows an empty set. You must create tables using the table command. So let’s talk about creating a command table.
Computer Class 5 Solution
In the above statement, each column definition is separated by a comma, MySQL displays the -> sign when you start a new line. A semicolon (;) is used to end a command.
In the screenshot above, look at the last line of the create table command, with pid given as the primary key.
This command is used to determine the status of the table. You can use the description or desc command for the table.
Handling data in MySQL can be done using different commands. These commands are: INSERT, UPDATE, DELETE etc.
Cool Data Science Projects Ideas For Beginners And Experts
You can see columns with null values that are not given in parentheses before the word value. Note the following:
Unit 3 Database Management In this unit of Computer Science Class 12, we will cover SQL database queries. At the data prompt, select the command to be used. It has different characteristics. You can use SELECT to retrieve records from a relation. You can use the option command to find:
This command drops the ‘cardiac’ department record from the table and returns all the remaining records. Check the results:
Logical operations are used to connect more than one structure at a time. It is also used to define a range, a list of values and exclusions of values. There are three operators used in this section:
Mysql Worksheets With Answers
Note: When you use the range and operator you don’t want to include only the start value and the end value. The middle- and operator includes the highest and lowest values of the range in the output. Now look at this question.
The in and or operators are used to retrieve records from a column. Record from the same session here. You can provide a list of similar values. Now if you want to display values that are not in a specified format, you can use the operator. Check out this quiz and the results:
The is and is not operator is used to retrieve records from a table that contain null values. If you want to get a null value record. Consider this question:
The like operator is used to retrieve records by identifying the type. _ is used for a fixed view point and for any text, it is %
Cuet 2022 Syllabus Computer Science
Class 10 science important questions with answers, class 9 science notes, class 7 science notes, science notes class 10, political science class 11 important questions, sql queries in access, class 12 computer science notes, class 4 science questions, class 7 science questions, important questions for class 10 science, queries in microsoft access, using queries in access
Class 12 Notes Computer Science Using Queries In Access Important Short Questions. There are any Class 12 Notes Computer Science Using Queries In Access Important Short Questions in here.