feat: add UPDATE/DELETE support with cache invalidation (v0.4.0)

- Implement UPDATE statement with WHERE clause support
- Implement DELETE statement with WHERE clause support
- Add cache invalidation on write operations (INSERT/UPDATE/DELETE)
- Fix projection-correct SELECT with column/alias validation
- Add schema-safe INSERT/UPDATE with type coercion
- Add comprehensive tests for new functionality
- Update README and CHANGELOG for v0.4.0

Author: aviralgarg05

CHANGELOG.md

@@ -5,6 +5,23 @@ All notable changes to NexumDB will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [0.4.0] - 2026-02-03
+
+### Added
+- Projection-aware SELECT with alias support
+- SHOW TABLES, DESCRIBE, and DROP TABLE (IF EXISTS)
+- Best-effort coercion for INSERT/UPDATE with schema validation
+- Full cache invalidation on data writes
+- Catalog persistence test coverage
+
+### Changed
+- StorageEngine clone now shares underlying sled database
+- Semantic cache keys now include projection, WHERE, ORDER BY, LIMIT
+
+### Tests
+- Added projection, coercion, and table management coverage
+- Extended integration tests for table lifecycle
+
 ## [0.3.0] - 2025-11-26
 
 ### Added
@@ -111,6 +128,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - 60x query speedup on cache hits
 - Local-only execution (no cloud dependencies)
 
+[0.4.0]: https://github.com/aviralgarg05/NexumDB/compare/v0.3.0...v0.4.0
 [0.3.0]: https://github.com/aviralgarg05/NexumDB/compare/v0.2.0...v0.3.0
 [0.2.0]: https://github.com/aviralgarg05/NexumDB/compare/v0.1.0...v0.2.0
 [0.1.0]: https://github.com/aviralgarg05/NexumDB/releases/tag/v0.1.0

Cargo.lock

@@ -12,6 +12,12 @@ An innovative, open-source database that combines traditional SQL with AI-powere
 
 ## Features
 
+### v0.4.0 - Core Correctness & Table Management
+- **Projection-Correct SELECT**: Column/alias projection with schema validation
+- **Schema-Safe Writes**: INSERT/UPDATE validation with best-effort coercion
+- **Table Management**: SHOW TABLES, DESCRIBE, DROP TABLE (IF EXISTS)
+- **Cache Safety**: Query cache keys include WHERE/ORDER/LIMIT + full invalidation on writes
+
 ### v0.3.0 - Advanced SQL & Persistent Learning
 - **Advanced SQL Operators**: LIKE (pattern matching), IN (list membership), BETWEEN (range queries)
 - **Query Modifiers**: ORDER BY (multi-column sorting), LIMIT (result truncation)
@@ -126,6 +132,8 @@ INSERT INTO users (id, name, age) VALUES (1, 'Alice', 30), (2, 'Bob', 25);
 
 -- Simple query
 SELECT * FROM users;
+SELECT id, name FROM users;
+SELECT name AS display_name FROM users;
 
 -- WHERE clause filtering (v0.2.0)
 SELECT * FROM users WHERE age > 25;
@@ -147,6 +155,15 @@ WHERE price BETWEEN 100 AND 500
   AND name LIKE 'L%'
 ORDER BY price DESC 
 LIMIT 10;
+
+-- Table management (v0.4.0)
+SHOW TABLES;
+DESCRIBE users;
+DROP TABLE IF EXISTS users;
+
+-- Data modification (v0.4.0)
+UPDATE users SET age = 31 WHERE id = 1;
+DELETE FROM users WHERE id = 2;
 ```
 
 ### Natural Language Queries (v0.2.0+)

README.md

@@ -1,6 +1,6 @@
 [package]
 name = "nexum_cli"
-version = "0.3.0"
+version = "0.4.0"
 edition = "2021"
 
 [[bin]]

nexum_cli/Cargo.toml

@@ -2,7 +2,7 @@ use nexum_core::{Catalog, Executor, NLTranslator, Parser, QueryExplainer, Storag
 use std::io::{self, Write};
 
 fn main() -> anyhow::Result<()> {
-    println!("NexumDB v0.2.0 - AI-Native Database with Natural Language Support");
+    println!("NexumDB v0.4.0 - AI-Native Database with Natural Language Support");
     println!("Initializing...\n");
 
     let storage = StorageEngine::new("./nexumdb_data")?;
@@ -32,7 +32,9 @@ fn main() -> anyhow::Result<()> {
     };
 
     println!("Ready. Commands:");
-    println!("  - SQL: Type any SQL query (CREATE TABLE, INSERT, SELECT)");
+    println!("  - SQL: Type any SQL query (CREATE, INSERT, SELECT, UPDATE, DELETE, DROP)");
+    println!("  - SHOW TABLES: List all tables");
+    println!("  - DESCRIBE <table>: Show table schema");
     println!("  - ASK: Type 'ASK <question>' for natural language queries");
     println!("  - EXPLAIN: Type 'EXPLAIN <query>' to see query execution plan");
     println!("  - EXIT: Type 'exit' or 'quit' to exit\n");

nexum_cli/src/main.rs

@@ -1,6 +1,6 @@
 [package]
 name = "nexum_core"
-version = "0.3.0"
+version = "0.4.0"
 edition = "2021"
 
 [dependencies]

nexum_core/Cargo.toml

@@ -109,6 +109,7 @@ impl Catalog {
 mod tests {
     use super::*;
     use crate::sql::types::DataType;
+    use tempfile::tempdir;
 
     #[test]
     fn test_catalog_operations() {
@@ -139,4 +140,34 @@ mod tests {
         assert_eq!(tables.len(), 1);
         assert_eq!(tables[0], "users");
     }
+
+    #[test]
+    fn test_catalog_persistence() {
+        let temp_dir = tempdir().unwrap();
+        let db_path = temp_dir.path().join("catalog_db");
+
+        {
+            let storage = StorageEngine::new(&db_path).unwrap();
+            let catalog = Catalog::new(storage);
+
+            let columns = vec![Column {
+                name: "id".to_string(),
+                data_type: DataType::Integer,
+            }];
+
+            catalog.create_table("persist_table", columns).unwrap();
+        }
+
+        {
+            let storage = StorageEngine::new(&db_path).unwrap();
+            let catalog = Catalog::new(storage);
+
+            let schema = catalog.get_table("persist_table").unwrap();
+            assert!(schema.is_some());
+            assert_eq!(schema.unwrap().name, "persist_table");
+
+            let tables = catalog.list_tables().unwrap();
+            assert_eq!(tables, vec!["persist_table".to_string()]);
+        }
+    }
 }