SQL Learning Modules

Covers statement termination, single-line and multi-line comments, literal value projection, system temporal functions, column aliasing, and NULL semantics under three-valued logic.

Filters rows using WHERE, comparison operators, Boolean logic (AND/OR/NOT), range BETWEEN, discrete IN sets, wildcard pattern matching (LIKE), and multi-column ORDER BY tie-breaking.

Implements conditional branching with CASE, fallback imputation with COALESCE, sentinel matching via NULLIF, type casting (CAST), and comprehensive string/numeric functions.

Computes summary metrics via COUNT, SUM, AVG, MIN, and MAX, groups categorical dimensions with GROUP BY, and filters groups using post-aggregation HAVING clauses.

Generates hierarchical summary rollups and cross-dimensional cross-tabulations using standard ROLLUP, CUBE, and explicit GROUPING SETS operators.

Connects normalized tables using INNER JOIN, LEFT/RIGHT/FULL OUTER JOIN, CROSS JOIN Cartesian products, self-joins for hierarchies, and anti-join exclusion patterns.

Structures queries into modular blocks using scalar subqueries, correlated subqueries, existential EXISTS predicates, and multi-stage Common Table Expressions (WITH CTE).

Traverses multi-level employee organizational charts and generates iterative sequences using recursive Common Table Expressions (WITH RECURSIVE).

Executes single-row and multi-row INSERT, bulk INSERT INTO SELECT, conditional UPDATE via CASE, DELETE with WHERE, high-speed TRUNCATE, and atomic UPSERT operations.

Architects relational structures with CREATE TABLE, type affinities, dynamic schema evolution via ALTER TABLE, CTAS materialization, and temporary session tables.

Enforces relational constraints via PRIMARY KEY, composite keys, FOREIGN KEY referential actions (CASCADE, SET NULL, RESTRICT), UNIQUE, NOT NULL, and CHECK rules.

Encapsulates queries with standard views, updatable views with INSTEAD OF triggers, and accelerates lookups using B-Tree, composite, partial, and covering indexes.

Manages atomic transactions with BEGIN, COMMIT, ROLLBACK, and SAVEPOINT, evaluating ANSI isolation levels and preventing dirty, non-repeatable, and phantom reads.

Computes non-collapsing analytics via OVER(), PARTITION BY, ranking (ROW_NUMBER, RANK, DENSE_RANK, NTILE), positional LAG/LEAD, running totals, and sliding frames.

Encapsulates reusable database routines using CREATE PROCEDURE, IN/OUT parameter modes, local variables, IF-THEN-ELSE control flow, loops, and database cursors.

Automates event-driven business rules and mutation audit logging using BEFORE and AFTER triggers on INSERT, UPDATE, and DELETE operations.

Configures user identities, privilege granting with GRANT and REVOKE, Role-Based Access Control (RBAC), and column-level security under the principle of least privilege.

Profiles query performance using EXPLAIN QUERY PLAN, evaluates index selectivity, writes Sargable predicates, avoids SELECT *, and implements keyset seek pagination.

Persists and queries semi-structured JSON documents, standardizes UTC dates, imputes missing NULL values, deduplicates rows, and runs automated quality audits.

Consolidates curriculum knowledge into 20 comprehensive standalone applications including POS cashiers, academic portals, star-schema data warehouses, and ETL pipelines.