What We Will Cover
Definition
Overview of Data Models
Types of Databases
Types of Databases
Types of Databases
Types of Databases
Types of Databases
Types of Databases
Relational Database Concepts
Relational Database Concepts
Relational Database Concepts
Constraints in Relational Databases
Constraints in Relational Databases
Constraints in Relational Databases
Understanding Different Types of SQL Commands
Understanding Our Practice Database
Table Name | Primary Key | Description | Key Columns |
---|---|---|---|
EMPLOYEES | employee_id | Core employee information | first_name, last_name, salary, department_id |
DEPARTMENTS | department_id | Department details | department_name, manager_id, location_id |
JOBS | job_id | Job positions | job_title, min_salary, max_salary |
LOCATIONS | location_id | Office locations | city, state_province, country_id |
Complete Database Structure & Relationships
Your First SQL Queries
Filtering Your Data
Finding Patterns in Your Data
Complex Filtering
Handling Missing Data
Never use = NULL or != NULL. Always use IS NULL or IS NOT NULL when checking for NULL values.
Organizing Your Results
Transforming Your Data
What We Will Cover
Summarizing Your Data
Function | Description | Example |
---|---|---|
COUNT(*) | Count all rows | SELECT COUNT(*) FROM employees |
SUM() | Sum of values | SELECT SUM(salary) FROM employees |
AVG() | Average of values | SELECT AVG(salary) FROM employees |
MAX() | Maximum value | SELECT MAX(salary) FROM employees |
MIN() | Minimum value | SELECT MIN(salary) FROM employees |
Keys and Foreign Keys
Combining Data from Multiple Tables
Connecting Multiple Data Sources
Queries within Queries
INSERT, UPDATE, DELETE, COMMIT, ROLLBACK
Session 2 Challenges
Applying SQL in the Workplace
What You've Learned
Learn from Errors
Continue Your SQL Journey
Advanced Analytical Functions
Optimizing Your Queries
Security Best Practices
Business Applications
Common Oracle SQL Errors
Error | Cause | Solution |
---|---|---|
ORA-00942 | Table or view does not exist | Check table name spelling and schema |
ORA-00904 | Invalid identifier | Verify column names and aliases |
ORA-00937 | Not a single-group function | Add missing GROUP BY clause |
ORA-02291 | Integrity constraint violated | Check foreign key relationships |
Test Your Understanding