Relational DB Concepts and Tables :Databases and SQL for Data Science with Python (IBM Data Analyst Professional Certificate) Answers 2025
1. Question 1
Which statements about a database are correct?
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✅ A database is a logically coherent collection of data with some inherent meaning
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❌ Data can only be added and queried but not modified
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❌ Only SQL can query data
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❌ All of the above
Explanation:
Databases can be modified, and SQL is not the only way to query data (NoSQL exists).
Only the first statement is correct.
2. Question 2
Attributes of an entity become ________ in a table.
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❌ keys
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✅ columns
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❌ rows
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❌ constraints
Explanation:
Entity attributes → columns in a relational table.
3. Question 3
The CREATE TABLE statement is a ________.
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❌ DML
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✅ DDL
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❌ DQL
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❌ All of the above
Explanation:
CREATE TABLE defines structure → Data Definition Language.
4. Question 4
Command to remove a table and all its data:
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❌ TRUNCATE
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❌ ALTER
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✅ DROP table command
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❌ CREATE
Explanation:
DROP TABLE removes the entire table structure + data.
5. Question 5
Correct syntax to add a column ID with 7-character alphanumeric values in MySQL:
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❌ ALTER Employees ADD COLUMN ID varchar(7)
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❌ ALTER Employees TABLE ADD ID char
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❌ ALTER TABLE COLUMN Employees ID char(7)
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✅ ALTER TABLE Employees ADD ID char(7)
Explanation:
Syntax structure for MySQL:
ALTER TABLE table_name ADD column_name datatype;
🧾 Summary Table
| Q | Correct Answer | Key Concept |
|---|---|---|
| 1 | Only first statement | Database basics |
| 2 | Columns | Attributes → columns |
| 3 | DDL | CREATE TABLE |
| 4 | DROP TABLE | Remove table completely |
| 5 | ALTER TABLE Employees ADD ID char(7) | ALTER TABLE syntax |