Free developer tools and practical guides for SQL, data workflows, and debugging.
AAskDBSQL & Data Toolkit

Knowledge Base

Guides and cheat sheets for practical engineering work

Explore SQL, data, web, and tooling topics with concise explanations and implementation-first examples.

59

Published guides

9

Technical categories

Hands-on

Example-focused writing

AI14 min

RAG Architecture Guide: Building Retrieval-Augmented Generation Systems

Complete guide to RAG: embeddings, chunking, vector stores, hybrid search, and production integration.

AI12 min

OpenAI API Best Practices for Production

Retry logic, streaming, token budgeting, prompt caching, and cost control for the OpenAI API.

AI13 min

AI Agent Design Patterns: ReAct, Tool Use, Memory, and Multi-Agent Systems

Production-ready patterns for AI agents: ReAct, tool-use, memory strategies, and multi-agent orchestration.

AI11 min

Vector Database Comparison: Pinecone vs Weaviate vs Chroma vs pgvector

Compare vector databases for AI: performance, pricing, features, and integration patterns.

AI13 min

LLM Fine-Tuning Guide: LoRA, Data Prep, and Evaluation

When to fine-tune, how to prepare data, LoRA/QLoRA techniques, and evaluation strategies.

AI11 min

AI Cost Optimization: Reducing LLM API Costs in Production

Semantic caching, model routing, Batch API, prompt compression, and token budgeting strategies.

AI10 min

Structured Output from LLMs: JSON Mode, Function Calling, Zod Validation

Get reliable structured output from LLMs using JSON schema, function calling, and runtime validation.

AI12 min

AI Observability: Monitoring LLM Applications in Production

Trace LLM calls, track latency and costs, detect quality regressions, and set up AI dashboards.

AI13 min

Prompt Engineering Guide: Advanced Techniques for Production LLMs

Chain-of-thought, few-shot, self-consistency, meta-prompting, and prompt testing in CI.

AI13 min

LangChain Guide: Chains, Agents, Memory, and LCEL Patterns

Practical LangChain patterns: LCEL, RAG chains, tool-using agents, memory, and streaming.

AI12 min

AI Security: Prompt Injection, Jailbreaks, and LLM Guardrails

Defend against prompt injection, jailbreaks, indirect attacks, and data exfiltration in LLM applications.

AI12 min

Semantic Search: Embeddings, Cosine Similarity, and Hybrid Search

Build semantic search with embeddings, BM25 hybrid search, reranking, and query expansion.

AI12 min

AI Streaming Guide: SSE, ReadableStream, and Edge Deployment

Stream LLM responses token-by-token using SSE, ReadableStream, Vercel AI SDK, and edge functions.

AI13 min

Multimodal AI Guide: Vision, Audio, and Document Processing

Image analysis, invoice extraction, audio transcription, and PDF processing with GPT-4o and Gemini.

AI11 min

Context Window Management: Long Documents and Memory Strategies

Sliding window, recursive summarization, map-reduce, and RAG for managing LLM context limits.

AI12 min

Embeddings Deep Dive: Models, Dimensions, and Production Patterns

Embedding model comparison, batching, caching, deduplication, classification, and recommendation.

AI12 min

AI Testing Guide: Unit Tests, Evals, and Mocking LLMs

Mock LLM APIs, write prompt snapshot tests, build eval frameworks, and integrate into CI.

AI12 min

Model Context Protocol (MCP) Guide: Build AI Tool Integrations

Build MCP servers to connect AI clients to databases, files, and APIs using the open standard.

AI11 min

Function Calling Deep Dive: OpenAI, Anthropic, and Gemini

Parallel calls, forced calling, argument validation, and error handling across all major LLM APIs.

AI12 min

Anthropic Claude API Guide: Messages, Tool Use, Vision, and Cost Control

Claude messages API, extended thinking, prompt caching, streaming, and production patterns.

AI13 min

AI Chatbot Architecture: From Prototype to Production

Session state, context assembly, intent routing, entity memory, rate limiting, and fallback chains.

AI12 min

LLM Router and Gateway: Provider Switching, Fallbacks, and Cost Control

Build an LLM gateway with routing rules, multi-provider fallbacks, and semantic caching.

AI12 min

AI Workflow Automation: Email Triage, Document Processing, and Code Review

Automate email triage, invoice extraction, code review bots, and document classification pipelines.

AI12 min

Knowledge Graphs and AI: GraphRAG and Structured Reasoning

Combine Neo4j knowledge graphs with LLMs for verified facts, multi-hop reasoning, and GraphRAG.

AI12 min

Harness AI Delivery Pipeline: Practical Blueprint

Build a release workflow with eval gates, canary rollouts, and rollback controls.

AI11 min

LLM Evaluation Pipeline Guide for Product Teams

Design robust dataset, scoring, and baseline comparison for production AI quality.

AI9 min

Prompt Regression Testing: Prevent Quality Drift

Catch regressions from prompt changes before deploying to real traffic.

AI12 min

AI CI/CD with Harness: End-to-End Blueprint

Reference architecture for shipping AI systems with operational guardrails.

SQL10 min

SQL Cheat Sheet: Complete Quick Reference

A single-page SQL reference for writing, filtering, grouping, and joining faster.

SQL8 min

SQL JOINs Explained: Visual Guide

Learn inner, left, and right joins with practical business examples.

SQL10 min

Top 20 SQL Interview Questions

Common interview patterns with reasoning and sample solutions.

SQL8 min

SQL Window Functions: A Practical Guide

How to rank, compare, and aggregate while preserving row-level details.

SQL6 min

SQL GROUP BY Explained with Examples

Build reliable aggregation queries and avoid incorrect grouped results.

SQL5 min

SQL Format Best Practices for Teams

Formatting conventions that improve readability and code review quality.

SQL6 min

SQL vs NoSQL: When to Use Each

Choose the right data model by workload, consistency, and scaling needs.

SQL5 min

SQL Documentation with DDL

Turn schema files into maintainable technical documentation.

SQL7 min

PostgreSQL Cheat Sheet

Frequently used PostgreSQL syntax for tables, queries, and functions.

SQL4 min

Generate Test Data: CSV and JSON to SQL

Fast ways to generate insert-ready data for local and CI environments.

SQL3 min

DDL to Markdown Data Dictionary

Document table structures quickly with a structured markdown dictionary.

Languages8 min

JavaScript Cheat Sheet

Core JavaScript syntax and patterns for daily engineering tasks.

Languages8 min

Python Cheat Sheet

Practical Python essentials for scripts, automation, and data work.

Languages8 min

TypeScript Guide: Types and Best Practices

Use TypeScript types effectively to reduce runtime bugs and ambiguity.

Frameworks8 min

React Hooks Cheat Sheet

A compact guide to state, effects, memoization, and custom hooks.

CSS7 min

CSS Flexbox Guide

Design responsive one-dimensional layouts without brittle hacks.

CSS7 min

CSS Grid Guide

Build robust two-dimensional layouts with modern grid techniques.

Tools7 min

Regex Explained: How Regular Expressions Work

Understand regex building blocks before using copy-pasted patterns.

Tools7 min

Regex Cheat Sheet

A quick lookup for operators, quantifiers, groups, and assertions.

Tools4 min

Base64 Encoding Guide

When Base64 is useful, and where it should never be treated as encryption.

Data6 min

JSON vs YAML vs XML Comparison

Compare structure, readability, and ecosystem support across formats.

Data6 min

YAML Guide: Syntax and Examples

Write maintainable YAML for CI pipelines, configs, and automation.

Tools6 min

Markdown Syntax Cheat Sheet

A fast reference for writing clean Markdown docs and READMEs.

Web7 min

HTTP Status Codes Reference

Interpret and choose status codes that make APIs easier to debug.

Web7 min

REST API Design Best Practices

Conventions for stable, predictable APIs that scale across teams.

Web6 min

JWT Explained: How Tokens Work

Understand JWT structure, validation, and common security pitfalls.

DevOps7 min

Git Commands Cheat Sheet

Useful Git commands for branch workflows, merges, and history checks.

DevOps7 min

Docker Commands Cheat Sheet

Key Docker commands for image management and container operations.

DevOps8 min

Linux Commands Cheat Sheet

Command-line basics every developer uses for ops and troubleshooting.

DevOps5 min

NPM Commands Cheat Sheet

Daily npm commands for dependency management and script execution.

DevOps6 min

Vim Commands Cheat Sheet

Core movement and editing shortcuts to speed up terminal editing.