programming languages Online Quiz - 341
|Description: programming languages Online Quiz - 341|
|Number of Questions: 20|
|Created by: Aliensbrain Bot|
|Tags: programming languages|
You develop a Windows-Based application that accesses a Microsoft SQL Server database named ABC. Users must supply a user name and password when they start the application. This information is then used to dynamically build a connection string. When you test the application, you discover that it is not using the SqlClient connection pooling feature. You must reduce the time needed to retrieve information. How should you modify the connection string?
You are preparing a localized version of a Windows Form named ABCLocal. Users of ABCLocal speak a language that prints text from right to left. User interface elements on the form need to conform to this alignment. You must ensure that all user interface elements are properly formatted when the localized Windows Form runs. You must also ensure that ABCLocal is easy to update and maintain. What should you do?
You develop a Windows-based application that contains a form named ContactABC. You need to write code to initialize all class-level variables in ContactABC as soon as ContactABC is instantiated. You will place your code in a public procedure in the ContactABC class. Which public procedure should you use?
To answer this question, you need to understand the purpose of each public procedure in the ContactABC class. Let's go through each option to understand why it is correct or incorrect:
Option A) Create - This option is incorrect because the "Create" procedure is not a valid public procedure in the ContactABC class.
Option B) Initialize - This option is incorrect because the "Initialize" procedure is not a valid public procedure in the ContactABC class.
Option C) Load - This option is incorrect because the "Load" procedure is typically used to load data or perform initialization tasks when a form is loaded, not when the ContactABC class is instantiated.
Option D) New - This option is correct because the "New" procedure is a valid public procedure in the ContactABC class. It is called when a new instance of the ContactABC class is created, allowing you to initialize class-level variables at that time.
The correct answer is D) New. This option is correct because it allows you to initialize all class-level variables in ContactABC as soon as it is instantiated.
You use Visual Studio .NET to create several Windows-based applications. All use a common class library assembly named ABCCustomers. You deploy the application to client computers on your company intranet. Later, you modify ABCCustomers.Any application that uses version 188.8.131.52 must now user version 184.108.40.206. What should you do?
You develop a Windows-based application ABCApp by using Visual Studio .NET. ABCApp uses a SqlConnection object for database access. You typically run ABCApp on a computer that has limited RAM and hard disk space. After the code finishes using the SqlConnection object, you must ensure that the connection is closed and that any resources consumed by the object are released immediately. What should you do?
You plan to develop a customer information application CustomABC that uses a Microsoft SQL Server database. CustomABC will be used frequently by a large number of users. Your application code must obtain the fastest possible performance when accessing the database and retrieving large amounts of data. You must accomplish this goal with the minimum amount of code. How should you design CustomABC?
You use Visual Studio .NET to develop a component named ABCComponent. You plan to develop several client applications that use ABCComponent. You need to deploy ABCComponent with each of these applications. You will create a distribution package to be included with each application. Which type of project should you create?
To solve this problem, the user needs to know the SQL syntax for adding a primary key to a table using the ALTER TABLE statement.
A primary key is a column or set of columns that uniquely identifies each row in a table. It is a constraint that ensures that the values in the column(s) are unique and not null.
Now let's go through each option and explain why it is right or wrong:
A. ALTER TABLE students ADD PRIMARY KEY student_id;
This statement is incorrect because it is missing the keyword "CONSTRAINT". The correct syntax for adding a primary key constraint is "ADD CONSTRAINT".
B. ALTER TABLE students ADD CONSTRAINT PRIMARY KEY(student_id);
This statement is incorrect because it is missing the name of the constraint. All constraints should have a unique name for easy identification and management.
C. ALTER TABLE students ADD CONSTRAINT stud_id_pk PRIMARY KEY student_id;
This statement is incorrect because the syntax is wrong. The correct syntax for adding a primary key constraint is "ADD CONSTRAINT PRIMARY KEY ()".
D. ALTER TABLE students ADD CONSTRAINT stud_id_pk PRIMARY KEY (student_id);
This statement is correct. It adds a primary key constraint named "stud_id_pk" to the "students" table on the "student_id" column.
E. ALTER TABLE Students MODIFY CONSTRAINT stud_id_pk PRIMARY KEY (student_id);
This statement is incorrect because it uses the "MODIFY CONSTRAINT" syntax, which is not valid for adding constraints.
Therefore, the correct answer is:
The Answer is: D. ALTER TABLE students ADD CONSTRAINT stud_id_pk PRIMARY KEY (student_id);