sqlglot is a SQL parser and transpiler that represents queries as abstract syntax trees to enable structural analysis, modification, and semantic transformation. It functions as a dialect translator and query optimizer, converting SQL code between different database engines and simplifying syntax trees through rule-based normalization.
The project provides a framework for defining custom SQL dialects by overriding tokenizers, parsers, and generators. It includes a lineage analyzer to track data flow from source tables through complex queries to identify the origin of specific columns.
Additional capabilities cover programmatic SQL generation, syntax validation, and schema-aware type inference. The system can generate logical plans for query planning, extract metadata, and execute queries in-memory using Python dictionaries as data sources.
