Coding/Learn/sql/sql quiz
SQL & Relational Database Engineering Complete Course
01.Introduction & Relational Database Architecture
02.Syntax, Clauses & Execution Order
03.SELECT: Column Projection & Expressions
04.SELECT DISTINCT & Row Deduplication
05.WHERE Clause: Filtering Predicates & Comparison
06.ORDER BY: Sorting, Multi-Column & NULLS Ordering
07.Logical Operators: AND, OR, NOT & Operator Precedence
08.Comments: Single-Line (--), Multi-Line (/* */) & Query Hints
09.Operators: Arithmetic, Bitwise & String Concatenation
10.LIKE Operator & Wildcard Characters (%, _)
11.IN & NOT IN: Membership Operators & Subqueries
12.BETWEEN: Range Filtering for Numbers, Dates & Text
13.NULL Values: Three-Valued Logic, IS NULL & IS NOT NULL
14.Aliases: AS Keyword for Columns & Tables
15.SELECT TOP, LIMIT & OFFSET Pagination
16.INSERT INTO: Single & Multi-Row Insertions
17.UPDATE: Modifying Existing Records & Safe WHERE Rules
18.DELETE: Removing Rows vs TRUNCATE TABLE
19.SELECT INTO & Table Backups (CREATE TABLE AS SELECT)
20.INSERT INTO SELECT: Bulk Data Migration
21.Aggregate Functions: Statistical Summaries
22.MIN() & MAX(): Finding Extremes Across Types
23.COUNT: COUNT(*), COUNT(column) & COUNT(DISTINCT)
24.SUM() & AVG(): Numerical Aggregation & Averages
25.GROUP BY: Aggregation Buckets & Categorical Metrics
26.HAVING: Filtering Aggregated Groups vs WHERE
27.Joins Architecture: Relational Modeling & Venn Diagrams
28.INNER JOIN: Matching Intersections Across Tables
29.LEFT JOIN: Preserving Unmatched Left Rows & Finding Orphans
30.RIGHT JOIN: Preserving Unmatched Right Rows
31.FULL JOIN: Full Outer Join & Complete Reconciliation
32.SELF JOIN: Hierarchies, Trees & Parent-Child Relationships
33.UNION: Combining Result Sets with Automatic Deduplication
34.UNION ALL vs UNION: Performance & Duplicates
35.EXISTS & NOT EXISTS: Correlated Subqueries
36.ANY & ALL: Quantified Comparison Subqueries
37.CASE: Conditional Expressions & Data Transposition
38.Null Functions: COALESCE, IFNULL, ISNULL & NULLIF
39.Stored Procedures, Functions & Query Parameters
40.CREATE & DROP DATABASE: Environment Lifecycle
41.CREATE TABLE: Defining Schemas & Types
42.DROP & TRUNCATE TABLE: Structure vs Data Purging
43.ALTER TABLE: Modifying Columns & Schema Evolution
44.AUTO INCREMENT & Sequences: Identity Generation
45.Date & Time Formats: Timestamp Manipulation
46.Views: Virtual Tables & Security Layers
47.Constraints Overview: Relational Integrity
48.NOT NULL & UNIQUE: Data Invariants
49.PRIMARY KEY: Entity Uniqueness & Clustering
50.FOREIGN KEY: Referential Integrity & Cascades
51.CHECK & DEFAULT: Business Rules at DB Layer
52.CREATE INDEX: B-Trees & Query Optimization
53.Injection Defense: Threat Models & Prevention
54.Parameters & Prepared Statements: Safe Execution
55.Database Engines & Hosting Architecture
56.Dialect References & Data Type Standards
57.Production Best Practices & Query Tuning Checklist
58.Interactive Exercises: Multi-Table Analytics Challenges
59.Comprehensive Assessment & Knowledge Check
60.Capstone Project: Enterprise Analytics Engine
61.Mastery Certification & Graduate Verification
Course Certificate0%

Complete all lessons to earn

LearnSQL Comprehensive Assessment & Knowledge Check
59 / 61 0%
Lesson 59 of 61
5 mins read

SQL Comprehensive Assessment & Knowledge Check

PreviousNext Lesson
In Plain English

A comprehensive knowledge verification covering all foundational and advanced SQL concepts: 3-Valued Logic and NULL behaviors, ACID transaction isolation, B-Tree index mechanics, JOIN algorithms (Nested Loop, Hash, Merge Join), correlated subqueries, and SQL injection prevention.

The Mental Model

"The comprehensive assessment is your engineering review board: proving that you not only know how to write queries, but why the engine executes them the way it does."

Deep Dive: How It Works

Question 1: Explain the functional difference between `WHERE` and `HAVING`.

Question 2: Why does `NOT IN` return zero rows if the subquery contains a single NULL value?

Question 3: How does a composite index on `(A, B)` behave when querying on column `B` alone?

Question 4: What are the two distinct compilation phases of a Prepared Statement?

Syntax Blueprint

+---------------------------------------------------------+
| SQL KNOWLEDGE MATRIX: AUDIT PASSED                      |
| Relational Algebra | ACID Transactions | Query Planner  |
| Index Optimization | Schema Evolution  | Safe Execution |
+---------------------------------------------------------+

Verified conceptual mastery across all 10 SQL curriculum domains.

PointCore Rules to Remember

Point star
Full Stack Competency: Validates DDL, DML, DQL, Indexing, and Security principles.
Point star
Interview Ready: Prepares you for technical database design and query optimization interviews.
Point star
Architectural Fluency: Ability to select optimal indexing strategies and design normalized schemas.

Common Beginner Traps & How to Fix Them

Mistake:Guessing query performance without inspecting `EXPLAIN` query plans.

Why it happens: Relying on intuition rather than actual database optimizer statistics.

How to fix: Always profile queries with execution plans to verify index usage.

Pro Tip: In database technical interviews, always clarify expected table size, read/write ratios, and indexing tradeoffs before writing schema definitions.

Live Interactive Example

Hit Run Code to see it live
SQL Assessment Audit Verification
Python 3.12
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
Output Console
Click "Run Code" to view the rendered output.
How it works: All assessment categories evaluated and passed.

Your Turn: Micro Challenge

No pressure! Edit the starter code below and test your solution with instant feedback.

Micro Exercise

Run Assessment Verification

  • PointSelect all records from `audit_checklist` where `status = 'VERIFIED'`.
1
2
3
4
5
6
7
8
9
Sandbox Output
Click "Run & Check" to test your solution.

Finished reading and practicing?

Mark this lesson as completed to update your course progress.

PreviousNext Lesson
Overview100 SheetLearnCertificates