Oracle Tutorial - 12. SQL Queries

---

12.1 Introduction to SQL Queries

Overview of SQL (Structured Query Language)

Importance of SQL in database management

Basic SQL syntax and commands

---

12.2 SELECT Statement

Retrieving data from a single table using SELECT

Specifying columns in the SELECT clause

Using aliases for column names

---

12.3 WHERE Clause

Filtering data using the WHERE clause

Comparison operators (e.g., =, <>, <, >, BETWEEN, LIKE)

Logical operators (e.g., AND, OR, NOT)

---

12.4 ORDER BY Clause

Sorting query results using ORDER BY

Sorting by multiple columns

Specifying ascending and descending order

---

12.5 Aggregate Functions

Calculating aggregate values (e.g., SUM, AVG, COUNT, MAX, MIN)

Using aggregate functions with GROUP BY clause

Filtering grouped data with HAVING clause

---

12.6 Joins

Performing inner joins between tables

Using aliases for table names

Performing outer joins (LEFT JOIN, RIGHT JOIN, FULL OUTER JOIN)

---

12.7 Subqueries

Writing subqueries within SELECT, FROM, WHERE, and HAVING clauses

Correlated vs. non-correlated subqueries

Using subqueries for filtering and aggregation

---

12.8 Set Operations

Combining query results with UNION, INTERSECT, and EXCEPT

Understanding set operations and their usage

---

12.9 Conditional Expressions

Using CASE expressions for conditional logic

Handling NULL values with CASE

Conditional aggregation with CASE and aggregate functions

---

12.10 String Functions

Common string functions (e.g., CONCAT, SUBSTRING, UPPER, LOWER, REPLACE)

Manipulating string data in SQL queries

---

12.11 Date and Time Functions

Common date and time functions (e.g., DATEADD, DATEDIFF, GETDATE, CONVERT)

Formatting date and time values

---

12.12 Advanced SQL Techniques

Using window functions for advanced analytics (e.g., ROW_NUMBER, RANK, DENSE_RANK)

Recursive queries with Common Table Expressions (CTEs)

Dynamic SQL and parameterized queries

---