15 extra multiple-choice questions for Structured Query Language (SQL) (12th Standard Computer Science, Samacheer Kalvi), beyond the ones printed in the textbook — each with the correct option highlighted and a clear, worked explanation. Free to read in English and Tamil.
Q1
What was the original name of the Structured Query Language (SQL) when it was developed at IBM's Research centre in the early 1970s?
- A. SEQUELCorrect
- B. SCRIPT
- C. ACCESS
- D. SYSTEM
Explanation. SQL was originally developed as SEQUEL at IBM's Research centre in the early 1970s before being renamed to SQL.
Q2
According to the textbook, in which year was the latest SQL standard mentioned released?
- A. 1986
- B. 1992
- C. 2008Correct
- D. 2012
Explanation. The textbook notes that the latest SQL standard was released in 2008 and named SQL 2008.
Q3
Relational Database Management Systems (RDBMS) include functions related to Create, Read, Update, and Delete operations. What is the collective abbreviation used for these operations?
- A. CRUDCorrect
- B. DDL
- C. TCL
- D. DML
Explanation. Create, Read, Update, and Delete operations are collectively known as CRUD in database platforms.
Q4
Which processing skill of SQL includes commands that allow users to define views of tables?
- A. Data Definition Language (DDL)
- B. Data Manipulation Language (DML)
- C. View DefinitionCorrect
- D. Authorization
Explanation. View Definition is one of the processing skills of SQL that defines custom views of tables.
Q5
Which of the following is a function performed by the Data Definition Language (DDL) in SQL?
- A. To insert new data into the database
- B. To specify the proper data type and define the size of a data itemCorrect
- C. To permanently save a database transaction
- D. To retrieve information stored in a database
Explanation. DDL is used to define database structures, which includes specifying data types and the sizes of data fields.
Q6
What type of DML requires a user to specify what data is needed without specifying how to get it?
- A. Procedural DML
- B. Non-Procedural DMLCorrect
- C. Transaction DML
- D. Structural DML
Explanation. Non-Procedural DML only requires the user to specify what data is needed without describing the method to retrieve it.
Q7
Which of the following SQL commands is classified under the Data Control Language (DCL)?
- A. ALTER
- B. COMMIT
- C. GRANTCorrect
- D. TRUNCATE
Explanation. The GRANT command is part of the Data Control Language, used for controlling access and privileges in a database.
Q8
Which command is used to restore the database to the last committed state or jump to a particular savepoint?
- A. COMMIT
- B. ROLLBACKCorrect
- C. SAVEPOINT
- D. REVOKE
Explanation. The ROLLBACK command is used to restore transactions to the last committed state or a named savepoint.
Q9
In SQL data types, which type represents a double-precision floating point number where the base 10 exponential precision exceeds 64?
- A. float
- B. real
- C. dec
- D. doubleCorrect
Explanation. The 'double' data type is identical to real except that its precision argument is allowed to exceed 64.
Q10
When two or more constraints, such as NOT NULL and UNIQUE, are applied to a single field in a table, what is this known as?
- A. Primary constraints
- B. Composite constraints
- C. Multiple constraintsCorrect
- D. Schema constraints
Explanation. Applying multiple distinct restrictions to a single column is referred to as multiple constraints.
Q11
According to the textbook, the UNIQUE constraint can be applied only to fields that have also been declared as which of the following?
- A. DEFAULT
- B. NOT NULLCorrect
- C. PRIMARY KEY
- D. CHECK
Explanation. The UNIQUE constraint must only be applied to fields that are explicitly defined with the NOT NULL constraint.
Q12
In a CREATE TABLE statement, where is a table constraint (which applies to a group of fields) normally specified?
- A. Immediately after the CREATE TABLE keyword
- B. At the end of the table definitionCorrect
- C. Inside the database configuration block
- D. Before any column names are declared
Explanation. A table constraint applies to multiple fields and is specified at the end of the table's column declarations.
Q13
In the textbook's example showing the DEFAULT constraint on the Student table, what default age is assigned to the 'Age' field?
- A. 15
- B. 17Correct
- C. 18
- D. 19
Explanation. The SQL query example in the textbook sets the Age field default value to 17 using 'Age integer DEFAULT 17'.
Q14
When the DISTINCT keyword is used in a SELECT query, how many NULL values are returned even if more than one NULL value exists in that column?
- A. None
- B. Only oneCorrect
- C. All of them
- D. An error is thrown
Explanation. When using the DISTINCT keyword, only a single NULL value is returned even if the column has multiple duplicate NULL entries.
Q15
What is the default sorting order of the ORDER BY clause in an SQL statement?
- A. Descending order
- B. Ascending orderCorrect
- C. Chronological order
- D. Unsorted original order
Explanation. By default, sorting using the ORDER BY clause is executed in ascending order.
About these Structured Query Language (SQL) questions
These are the Additional multiple-choice questions for Structured Query Language (SQL) from the Tamil Nadu State Board (Samacheer Kalvi) 12th Standard Computer Science syllabus. Each question shows the correct option and an original, step-by-step explanation so you understand the method, not just the answer. Use the answer key above to jump to any question, then take the practice test to check yourself under exam-like conditions.
Frequently asked questions
How many MCQs are there in Structured Query Language (SQL)?
This chapter has 15 book-back multiple-choice questions, each with the correct answer and a step-by-step explanation.
Are these 12th Standard Computer Science MCQs free to practise online?
Yes. Every question, answer and explanation here is free, and you can also take them as a timed practice test.
Where can I find the Structured Query Language (SQL) book-back answers?
The correct option for each question is highlighted on this page with a worked explanation, plus a quick answer-key summary at the top.
