Question

Amit wants to be familiar with SQL. One of his friends Anand suggests him to execute the following SQL commands:
(A) Create Table Student
(B) Use Database DB
(C) Select * from Student
(D) Insert into Student
In which order Amit needs to run the above commands?

• A. (A), (B), (C), (D)
• B. (A), (B), (D), (C)
• C. (B), (A), (D), (C)
• D. (C), (B), (D), (A)

Answer 1

The Correct Option is C

To execute SQL commands in a structured manner, Amit should follow a logical sequence. Here are the steps with explanations: 

1. Use Database DB: First, you need to select the database you want to work with in SQL. This is done using 'USE Database DB'. Configuring the context ensures that the subsequent commands affect the correct database.
2. Create Table Student: Next, create the necessary table where data will be inserted. This is achieved with 'CREATE TABLE Student'. This statement defines the table's structure, including the columns and their data types.
3. Insert into Student: Once the table is ready, you can add data into it using 'INSERT INTO Student'. This command populates the table with the desired data.
4. Select * from Student: Lastly, retrieve the data from the table using 'SELECT * FROM Student'. This command fetches all the records from the Student table, allowing you to review the data that has been inserted.

Following this order is crucial to ensure the SQL commands are correctly executed: (B), (A), (D), (C).

Answer 2

The correct order for Amit to execute the SQL commands is (B), (A), (D), (C).

Additional Context:

• Proper SQL Execution Sequence:
  • (B) Use Database DB: First select the database to work with
  • (A) Create Table Student: Then create the table structure
  • (D) Insert into Student: Add data to the created table
  • (C) Select * from Student: Finally query the populated table
• Comparison with Other Options:
  • Option (1): Incorrect (tries to create table before selecting database)
  • Option (2): Incorrect (same issue as Option 1, plus queries before inserting)
  • Option (4): Incorrect (tries to query non-existent table first)
• SQL Command Flow Logic:
  • 1. Database selection (USE)
  • 2. Table creation (CREATE)
  • 3. Data manipulation (INSERT)
  • 4. Data retrieval (SELECT)
• Practical Example:

  -- Correct execution sequence:
  USE DB;                     -- Select database
  CREATE TABLE Student (...);  -- Create table
  INSERT INTO Student (...)    -- Insert data
  VALUES (...);
  SELECT * FROM Student;       -- View data
      

• Error Prevention:
  • Attempting to create a table without selecting a database may fail
  • Querying a table before it exists or has data returns errors/empty results

Correct Answer: (3) (B), (A), (D), (C)