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.
Description : Integrity constraints ensure that changes made to the database by authorized users do not result into loss of data consistency. Which of the following statement(s) is (are) true w.r.t. the examples of integrity constraints? (A) An ... ) and (B) are true; (C) false. (4) (A), (B) and (C) are false.
Last Answer : Answer: 3
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
Description : NULL value means : (i) 0 value (ii) 1 value (iii) None value (iv) None of the above -Technology
Last Answer : Correct option (d) None value
Description : In Pandas the function used to check for null values in a DataFrame is ..... -Technology
Last Answer : In Pandas the function used to check for null values in a DataFrame isisnull()
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.
Description : Define primary key with an example. -Technology
Description : What is primary key? Give an example. -Technology
Description : What is a primary key in database? Give an example. -Technology
Description : Give one advantage of using primary key. -Technology
Last Answer : A primary key uniquely identifies the record in the table.
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.
Description : What is the utility of primary key in database? Write distinct features of primary keys. -Technology
Last Answer : 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.
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.
Description : Primary key is used to …………….. identify the record. -Technology
Last Answer : Primary key is used to uniquelyidentify the record.
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.
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.
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.
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.
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.
Description : Define primary key. How do you set it in MS_Access? -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.
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
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.
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.
Description : Write any one similarity and one difference between primary key and unique Constraint -Technology
Description : can we create a null as a key for a map collection ?
Last Answer : Ans. Yes , for Hashtable. Hashtable implements Map interface.
Description : In RDBMS, the constraint that no key attribute (column) may be NULL is referred to as: (A) Referential integrity (B) Multi-valued dependency (C) Entity Integrity (D) Functional dependency
Last Answer : (C) Entity Integrity
Description : Consider the following statements regarding relational database model: (a) NULL values can be used to opt a tuple out of enforcement of a foreign key. (b) Suppose that table T has only one candidate key. If Q is in 3NF, then it is ... true. (C) (b) and (c) are true. (D) (a), (b) and (c) are true.
Last Answer : (D) (a), (b) and (c) are true.
Description : Pointer holds A) Value of variable B) Address of variable C) Value and address of variable D) Always null
Last Answer : B) Address of variable
Description : NULL is (A) the same as 0 for integer (B) the same as blank for character (C) the same as 0 for integer and blank for character (D) not a value
Last Answer : (D) not a value
Description : Write the significance of a foreign key. -Technology
Last Answer : A foreign key is used to Establish the relationship between any two tables of RDBMS.
Description : Key field is a unique identifier for each record. It is defined in the form of (a) rows (b) columns -Technology
Last Answer : (b) Key is a data item that allows you to uniquely identify individual occurrences which is defined as the column or set of columns.
Description : A foreign key is a reference of the ………….. key in another table. -Technology
Last Answer : A foreign key is a reference of the primary keyin another table.
Description : Which shortcut key is used to make the selected text italic? (a) Ctrl +I (b) Shift +I (c) F1 + I (d) None of these -Technology
Last Answer : (a) Ctrl+I is the shortcut key to make the selected text italic.
Description : What is the use of Enter and Esc key in a Slide Show? -Technology
Last Answer : Press Enter to move to the next slide and Esc to close the Slide Show.
Description : Set new timing, while rehearsing ……………… key is press. (a) Ctrl+T (b) T (c) M (d) O -Technology
Last Answer : (b) T key is used to set new timing while rehearsing.
Description : What is the shortcut key to display the Microsoft PowerPoint shortcut menu? -Technology
Last Answer : (c) Shift + F10 is the shortcut key to display the PowerPoint shortcut menu
Description : F4 key is used to start a Slide Show. -Technology
Last Answer : FalseF5 key is used to start a Slide Show.
Description : The contents of a cell can be changed by pressing F2 key on keyboard. -Technology
Last Answer : True F2 is a shortcut for making the cell editable.
Description : Control Unit is called the ………….. of a computer system. (a) heart (b) nerve centre (c) primary memory (d) All of these -Technology
Last Answer : (b) Nerve centre because it controls the overall processing of a computer system.
Description : …… memory is used to store large amount of information permanently. (a) RAM (b) ROM (c) Secondary (d) Primary -Technology
Last Answer : (c) Secondary memory is used to store large amount of information permanently.
Description : Which of the following statement is false? (a) Secondary storage is faster (b) Primary storage is both volatile and non volatile in nature. -Technology
Last Answer : (a) Secondary memory is the slowest and cheapest form of memory. It cannot be processed directly by the CPU and it must be first copied into RAM.
Description : State the primary goal of a DBMS. -Technology
Last Answer : To provide a convenient and efficient environment in which we can store and retrieve information.
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.
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.
Description : What are the primary interest of online attackers in spyware? -Technology
Last Answer : Primary interest of online attackers in spyware is using it to steal personal information for financial crimes such as carding and identity theft or to sell that information to someone else who then executes more traditional financial crimes.
Description : Name the primary law in India dealing with cyber crime and electronic commerce. -Technology
Last Answer : The primary law is Information Technology Act 2000.
Description : Why is it important to properly frame the null and alternative hypothesis?
Last Answer : It's the scientific method. You have to know what you are testing. The null hypothesis is that the relationship you think is there isn't there. You need the alternative hypothesis ... significant evidence to support the alternative hypothesis or else you can not disprove the null hypothesis.
Description : Why is 'fluther_disc' null or not an object on some Fluther pages?
Last Answer : Which pages, exactly?
Last Answer : that All Of vectors The value is ' zero ' to them Who Zero Vector Or Null Vector Says.