sqlite-ast 0.1a0

Python library for parsing SQLite SELECT queries into an AST

sqlite-ast

Python library for parsing SQLite SELECT queries into an AST

Installation

Install this library using pip:

pip install sqlite-ast

Usage

The main entry point is parse(sql), which returns a nested Python dictionary:

from sqlite_ast import parse

ast = parse("select 1")
print(ast)

{'type': 'select', 'distinct': False, 'all': False, 'columns': [{'expr': {'type': 'integer', 'value': 1}, 'alias': None}], 'from': None, 'where': None, 'group_by': None, 'having': None, 'order_by': None, 'limit': None}

You can pretty-print that dictionary as JSON:

import json
from sqlite_ast import parse

ast = parse("select 1")
print(json.dumps(ast, indent=2))

{
  "type": "select",
  "distinct": false,
  "all": false,
  "columns": [
    {
      "expr": {
        "type": "integer",
        "value": 1
      },
      "alias": null
    }
  ],
  "from": null,
  "where": null,
  "group_by": null,
  "having": null,
  "order_by": null,
  "limit": null
}

If you want structured dataclass nodes instead of dictionaries, use parse_ast(sql):

from pprint import pprint
from sqlite_ast import parse_ast

node = parse_ast("select 1")
pprint(node)

Select(distinct=False,
       all=False,
       with_ctes=None,
       columns=[ResultColumn(expr=IntegerLiteral(value=1), alias=None)],
       from_clause=None,
       where=None,
       group_by=None,
       having=None,
       window_definitions=None,
       order_by=None,
       limit=None,
       offset=None,
       _has_limit=False,
       _compound_member=False)

Parse failures raise ParseError:

from pprint import pprint
from sqlite_ast import parse, ParseError

try:
    parse("select 1 union select")
except ParseError as e:
    print(e)
    print("\nPartial AST:")
    pprint(e.partial_ast)

Parse error at position 21: Unexpected token in expression: EOF ('')

Partial AST:
Select(distinct=False,
       all=False,
       with_ctes=None,
       columns=[ResultColumn(expr=IntegerLiteral(value=1), alias=None)],
       from_clause=None,
       where=None,
       group_by=None,
       having=None,
       window_definitions=None,
       order_by=None,
       limit=None,
       offset=None,
       _has_limit=False,
       _compound_member=True)

Development

To contribute to this library, first checkout the code. Then run the tests with uv:

cd sqlite-ast
uv run pytest