1.
What does SQL stand for?
Correct Answer
B. Structured Query Language
Explanation
SQL stands for Structured Query Language. It is a programming language used for managing and manipulating relational databases. SQL allows users to create, modify, and retrieve data from databases. It is widely used in database management systems and is essential for working with data in a structured and organized manner.
2.
Which SQL statement is used to extract data from a database?
Correct Answer
B. SELECT
Explanation
The SELECT statement is used to extract data from a database. It allows you to retrieve specific columns or rows from one or more tables based on specified criteria. This statement is fundamental in SQL and is commonly used to query databases and retrieve information for analysis or display purposes.
3.
Which SQL statement is used to update data in a database?
Correct Answer
A. UPDATE
Explanation
The UPDATE statement is used to modify or update data in a database. It allows you to change the values in one or more columns of a table. By specifying the table name, column names, and the new values, you can update the existing data in the database. The UPDATE statement is an essential part of SQL for making changes to the data stored in a database.
4.
Which SQL statement is used to delete data from a database?
Correct Answer
B. DELETE
Explanation
The correct answer is DELETE. The DELETE statement is used in SQL to delete data from a database. It allows you to specify the table from which data should be deleted and can also include conditions to specify which rows should be deleted. The DELETE statement is an essential part of managing and maintaining a database, as it allows you to remove unwanted or outdated data from the system.
5.
Which SQL statement is used to insert new data in a database?
Correct Answer
A. INSERT INTO
Explanation
The SQL statement "INSERT INTO" is used to insert new data into a database. This statement allows you to specify the table where the data should be inserted and provide the values for the new record. It is a commonly used statement in SQL for adding new records to a database table.
6.
With SQL, how do you select a column named aFirstNamea from a table named aPersonsa?
Correct Answer
C. SELECT FirstName FROM Persons
Explanation
The correct answer is "SELECT FirstName FROM Persons". This is the correct SQL syntax to select the column named "FirstName" from the table named "Persons". The "SELECT" keyword is used to specify the columns that you want to retrieve from the table, and "FROM" is used to specify the table from which you want to retrieve the data. In this case, "FirstName" is the specific column we want to select from the "Persons" table.
7.
With SQL, how do you select all the columns from a table named aPersonsa?
Correct Answer
A. SELECT * FROM Persons
Explanation
The correct answer is SELECT * FROM Persons. This SQL statement selects all the columns from the table named "Persons". The asterisk (*) is a wildcard character that represents all columns in the table. By using this statement, all the data from each column in the table will be retrieved.
8.
Which SQL statement is used to return only different values?
Correct Answer
A. SELECT DISTINCT
Explanation
The SQL statement "SELECT DISTINCT" is used to return only different values. It eliminates duplicate rows from the result set, ensuring that each row returned is unique. This is useful when you want to retrieve only the distinct values from a column or a combination of columns in a table. The other options, "SELECT UNIQUE" and "SELECT DIFFERENT," are not valid SQL statements.
9.
What does the abbreviation DBMS stand for?
Correct Answer
C. Database Management System.
Explanation
The correct answer is "Database Management System." DBMS stands for Database Management System, which refers to a software application that allows users to create, manipulate, and manage databases. It provides tools and functionalities to store, retrieve, and organize data efficiently, ensuring data integrity and security. Therefore, "Database Management System" is the appropriate explanation for the abbreviation DBMS.
10.
What is a 'tuple'?
Correct Answer
C. A row or record in a database table.
Explanation
A tuple refers to a row or record in a database table. In a relational database management system (RDBMS), data is organized into tables consisting of rows and columns. Each row represents a single record or instance of data, and a tuple is used to describe this individual row. It contains a set of values that correspond to the columns in the table. Therefore, the correct answer is "A row or record in a database table."