What is the utility of primary key in database? Write distinct features of primary keys. -Technology

What is the utility of primary key in database? Write distinct features of primary keys. -Technology
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The primary key is used to uniquely identify the record in a database. It can be a column or a set of columns in the table.Main features of the primary key are as follows:1. It must contain a unique value for each record of the table.2. It does not contain null values.
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What is a primary key in database? Give an example. -Technology

Description : What is a primary key in database? Give an example. -Technology

Last Answer : A field which uniquely identifies each record in a table is known as the primary key. e.g. emp id is the primary key of the Employee table.

Public key system is useful because a. it uses two keys. b. there is no key distribution problem as public key can be kept in a commonly accessible database. c. private key can be kept secret. d. it is a symmetric key system.

Description : Public key system is useful because a. it uses two keys. b. there is no key distribution problem as public key can be kept in a commonly accessible database. c. private key can be kept secret. d. it is a symmetric key system. 

Last Answer : b. there is no key distribution problem as public key can be kept in a commonly accessible database.  

Consider the following database table having A, B, C and D as its four attributes and four possible candidate keys (I, II, III and IV) for this table: Image I: {B} II: {B, C} III: {A, D} IV: {C, D} If different symbols stand for different values in the table (e.g., d1 is definitely not equal to d2), then which of the above could not be the candidate key for the database table? (A) I and III only (B) III and IV only (C) II only (D) I only

Description : Consider the following database table having A, B, C and D as its four attributes and four possible candidate keys (I, II, III and IV) for this table: I: {B} II: {B, C} III: {A, D} IV: {C, D} If ... the database table? (A) I and III only (B) III and IV only (C) II only (D) I only

Last Answer : (C) II only

Name two possible primary keys for an Employee table. -Technology

Description : Name two possible primary keys for an Employee table. -Technology

Last Answer : Possible primary keys for an Employee table are emp code, emp phone number.

A table can have multiple primary keys. -Technology

Description : A table can have multiple primary keys. -Technology

Last Answer : False If we create multiple primary keys in a table, the primary key will be unable to find the unique key value.

Write any one similarity and one difference between primary key and unique Constraint. -Technology

Description : Write any one similarity and one difference between primary key and unique Constraint. -Technology

Last Answer : Similarity: Column with both the constraints will only take unique values.Difference: Column with Primary key constraints will not be able to hold NULL values while Column with Unique constraints will be able to hold NULL values.

Write any one similarity and one difference between primary key and unique Constraint -Technology

Description : Write any one similarity and one difference between primary key and unique Constraint -Technology

Last Answer : Similarity: Column with both the constraints will only take unique values.Difference: Column with Primary key constraints will not be able to hold NULL values while Column with Unique constraints will be able to hold NULL values.

Explain Database Management. What are the features of DBMS? -Technology

Description : Explain Database Management. What are the features of DBMS? -Technology

Last Answer : It refers to the software that is responsible for storing, maintaining and utilising a database. It enables a user to define, create and maintain the database and provide controlled access on it. A ... Data security e.g. MS-Access, Corel Paradox, Lotus Approach, MySQL, OpenOffice.org Base etc.

Which of the following statements is FALSE about weak entity set ? (A) Weak entities can be deleted automatically when their strong entity is deleted. (B) Weak entity set avoids the data duplication and consequent possible inconsistencies caused by duplicating the key of the strong entity. (C) A weak entity set has no primary keys unless attributes of the strong entity set on which it depends are included. (D) Tuples in a weak entity set are not partitioned according to their relationship with tuples in a strong entity set.

Description : Which of the following statements is FALSE about weak entity set ? (A) Weak entities can be deleted automatically when their strong entity is deleted. (B) Weak entity set avoids the data ... weak entity set are not partitioned according to their relationship with tuples in a strong entity set.

Last Answer : (D) Tuples in a weak entity set are not partitioned according to their relationship with tuples in a strong entity set.

Which of the following statement is true? (1) A Primary key is also a candidate key (2) Each relation has at least one foreign key (3) Foreign keys can’t have null values (4) A Primary key is also an alternate key

Description : Which of the following statement is true? (1) A Primary key is also a candidate key (2) Each relation has at least one foreign key (3) Foreign keys can’t have null values (4) A Primary key is also an alternate key

Last Answer : Foreign keys can’t have null values

Write the shortcut keys to format the text style bold, italic and underline. -Technology

Description : Write the shortcut keys to format the text style bold, italic and underline. -Technology

Last Answer : Bold – Ctrl+B, Italic – Ctrl+I, Underline – Ctrl+U

What do you understand by network utilities? Write some cpmmands to start a network utility? -Technology

Description : What do you understand by network utilities? Write some cpmmands to start a network utility? -Technology

Last Answer : Network utilities provide a way to check the connectivity of a network and log events while using the Internet, ipconfig, ping, spray etc., are some commands to start a network utility.

What are the two distinct stages of message transmission in the two step flow theory? -Technology

Description : What are the two distinct stages of message transmission in the two step flow theory? -Technology

Last Answer : The Two Step Flow theory proposed by Paul Lazarsfeld, states that messages from the media get transmitted in two distinct stages:1. Through Opinion Leaders who pay close attention to the mass ... 2. These opinion leaders then pass their own interpretations in addition to the actual media content.

What is a primary key? -Technology

Description : What is a primary key? -Technology

Last Answer : A field which uniquely identifies each record in a table is known as the primary key. e.g. emp id is the primary key of the Employee table.

Define primary key with an example. -Technology

Description : Define primary key with an example. -Technology

Last Answer : A field which uniquely identifies each record in a table is known as the primary key. e.g. emp id is the primary key of the Employee table.

What is primary key? Give an example. -Technology

Description : What is primary key? Give an example. -Technology

Last Answer : A field which uniquely identifies each record in a table is known as the primary key. e.g. emp id is the primary key of the Employee table.

Give one advantage of using primary key. -Technology

Description : Give one advantage of using primary key. -Technology

Last Answer : A primary key uniquely identifies the record in the table.

What is the significance of a primary key? -Technology

Description : What is the significance of a primary key? -Technology

Last Answer : A primary key cannot allow null values and must have a unique index.

Which of the following fields will not make a suitable primary key? (a) A customer’s account number -Technology

Description : Which of the following fields will not make a suitable primary key? (a) A customer’s account number -Technology

Last Answer : (b) From the given options, the data field can not be set as a primary key because it can’t be fixed for an object.

Primary key is used to …………….. identify the record. -Technology

Description : Primary key is used to …………….. identify the record. -Technology

Last Answer : Primary key is used to uniquelyidentify the record.

The candidate key, which is not used as primary key is called ………….. key. -Technology

Description : The candidate key, which is not used as primary key is called ………….. key. -Technology

Last Answer : The candidate key, which is not used as primary key is calledalternate key.

Primary key field gives us permission to record duplicate entry. -Technology

Description : Primary key field gives us permission to record duplicate entry. -Technology

Last Answer : False A primary key is a key which identifies records uniquely in a table so it does not give us permission to record duplicate entry.

A primary key field does not allow numbers. -Technology

Description : A primary key field does not allow numbers. -Technology

Last Answer : False Primary key has to identify a unique value which can be present in a table, in a number form also. It means primary key field allow number too.

A primary key value can be NULL. -Technology

Description : A primary key value can be NULL. -Technology

Last Answer : False The primary key of table is used to uniquely identify each and every row in the table. So, its all keys and columns must be defined as NOT NULL.

A foreign key is a primary key in another table. -Technology

Description : A foreign key is a primary key in another table. -Technology

Last Answer : True When a table’s primary key field is added to a related table in order to create the common field which relates two tables, it is called a foreign key in the related table.

What is a primary key? How do we set a primary key? -Technology

Description : What is a primary key? How do we set a primary key? -Technology

Last Answer : Primary key is the key which is used to uniquely identify the records into the table. To set the primary key you have to follow the steps given below:Step 1 Select the field that you want ... 2 Click Primary Key button from the Design tab.orRight click on the selected field and select Primary Key.

Define primary key. How do you set it in MS_Access? -Technology

Description : Define primary key. How do you set it in MS_Access? -Technology

Last Answer : Primary key is the key which is used to uniquely identify the records into the table. To set the primary key you have to follow the steps given below:Step 1 Select the field that you want ... 2 Click Primary Key button from the Design tab.orRight click on the selected field and select Primary Key.

…………. is a field which is used as a primary key and numbers each record sequentially. -Technology

Description : …………. is a field which is used as a primary key and numbers each record sequentially. -Technology

Last Answer : AutoNumberis a field which is used as a primary key and numbers each record sequentially.

What is a primary key in a table? -Technology

Description : What is a primary key in a table? -Technology

Last Answer : A primary key is a special relational database table column (or combination of columns) designated to uniquely identify each & every table record. It does not contain NULL & duplicate values

Identify the primary key column of Train and Reservation. -Technology

Description : Identify the primary key column of Train and Reservation. -Technology

Last Answer : (i) Train-TrainIdReservation-RefNo(ii) (d) By default, the UNION operator selects all the values.

Consider the following database table : Create table test( one integer, two integer, primary key(one), unique(two), check(one≥1 and ≤10), check(two≥1 and ≤5) ); How many data records/tuples atmost can this table contain ? (A) 5 (B) 10 (C) 15 (D) 50

Description : Consider the following database table : Create table test( one integer, two integer, primary key(one), unique(two), check(one≥1 and ≤10), check(two≥1 and ≤5) ); How many data records/tuples atmost can this table contain ?  (A) 5 (B) 10 (C) 15 (D) 50

Last Answer : (A) 5 

In a relational database model, NULL values can be used for all but which one of the following? (A) To allow duplicate tuples in the table by filling the primary key column(s) with NULL. (B) To avoid confusion with actual legitimate data values like 0 (zero) for integer columns and ‘’ (the empty string) for string columns. (C) To leave columns in a tuple marked as “unknown” when the actual value is unknown. (D) To fill a column in a tuple when that column does not really “exist” for that particular tuple.

Description : In a relational database model, NULL values can be used for all but which one of the following? (A) To allow duplicate tuples in the table by filling the primary key column(s) with NULL. (B) To ... D) To fill a column in a tuple when that column does not really exist for that particular tuple.

Last Answer : (A) To allow duplicate tuples in the table by filling the primary key column(s) with NULL.

Write the relationship between a database and a table. -Technology

Description : Write the relationship between a database and a table. -Technology

Last Answer : A database contains multiple tables whereas, a table cannot exist outside a database.

Write any two advantages of using database. -Technology

Description : Write any two advantages of using database. -Technology

Last Answer : 1. Can ensure data security.2. Reduces the data redundancy.

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Description : Write any two uses of database management system. -Technology

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Define database management system. Write two advantages of using database management system for school. -Technology

Description : Define database management system. Write two advantages of using database management system for school. -Technology

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Write the steps to design a database. -Technology

Description : Write the steps to design a database. -Technology

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In a Bank’s database, there are two tables ‘Customer’ and ‘Transaction’ as shown below. Write a query to display customer’s name who has -Technology

Description : In a Bank’s database, there are two tables ‘Customer’ and ‘Transaction’ as shown below. Write a query to display customer’s name who has -Technology

Last Answer : (i) Select cust_name from customer c,transaction t where c.Acc_No=t.Acc_No and Transaction_Type= 'Debit';(ii)Select cust_name, t.* from customer c, transaction t where c.Acc_No=t.Acc_No;(iii) ... total amount of all type of transactions, it will only display the total of credit transactions only.

There are 12 function keys on the keyboard. -Technology

Description : There are 12 function keys on the keyboard. -Technology

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Which of the following shortcut keys brings the cursor to the last cell on the sheet that contains data? -Technology

Description : Which of the following shortcut keys brings the cursor to the last cell on the sheet that contains data? -Technology

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Description : Define a utility software. -Technology

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Mention some examples of utility software. -Technology

Description : Mention some examples of utility software. -Technology

Last Answer : Data compression utilities, virus protection utilities and disk defragmentation utilities.

Explain any one utility software. -Technology

Description : Explain any one utility software. -Technology

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What is the use of network utility? -Technology

Description : What is the use of network utility? -Technology

Last Answer : Network utility analyses the computer’s network connectivity, configure network settings, check the data transfer or log events. It works for the router to check whether the network is connected or not and other technical issues.

Describe utility software and also define its types. -Technology

Description : Describe utility software and also define its types. -Technology

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This part of utility software is used to prevent phosphor burning on computer monitors by blanking the screen with moving images. -Technology

Description : This part of utility software is used to prevent phosphor burning on computer monitors by blanking the screen with moving images. -Technology

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Utility programs include (a) Virus scanning software (b) Backup software -Technology

Description : Utility programs include (a) Virus scanning software (b) Backup software -Technology

Last Answer : (d) Utility programs includes virus scanning, backup, disk defragmenter software.

Which of the following is not related to a utility software? (a) Text editor (b) Antivirus program (c) Disk compression software -Technology

Description : Which of the following is not related to a utility software? (a) Text editor (b) Antivirus program (c) Disk compression software -Technology

Last Answer : (d) Railway reservation system is an example of application software whereas, rest all are software utilities.

Explain the utility of comments in XML. -Technology

Description : Explain the utility of comments in XML. -Technology

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