Why SQL comparisons with NULL do not behave like zero
Understand IS NULL, three-valued logic and the difference between COUNT(*) and COUNT(column).
SQL / PostgreSQL / NULL
TECHNOLOGY / KNOWLEDGE / PRACTICE
Search results: NULL handling
Materials on AI, Python, Git, SQL, SAP/ERP, statistics and time series: explanations, examples, practical tips, sources and applicability limits.
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Serializing Complex Python Objects to JSON with Custom Encoders
The json module handles only a fixed set of Python types. To serialize complex numbers, dates, paths, or user-defined classes you must supply a default function or subclass JSONEncoder, then pair the output with object_hook on the decode side.
json / serialization / JSONEncoder / default / object_hook / python-standard-library / datetime / complex
Choose a PostgreSQL foreign-key deletion policy without losing the wrong rows
Compare RESTRICT, CASCADE and SET NULL using a small isolated example, then check the actual constraint and dependent rows before changing real data.
PostgreSQL / SQL / Foreign keys / Transactions
Why JSON Schema Validation is Essential for LLM Outputs
A technical guide explaining why syntactically correct JSON from Large Language Models (LLMs) is insufficient for production systems and how JSON Schema provides the necessary structural and type guarantees.
LLM / JSON / JSON Schema / Data Validation / Software Engineering / Python