yobx.sql.sql_convert#

SQL to ONNX converter.

sql_to_onnx() converts a SQL query string into a self-contained onnx.ModelProto.

Design#

Every referenced column becomes a separate 1-D ONNX input so that the caller can supply column vectors independently (matching the convention used for tabular data). The converter processes the ParsedQuery operation list in execution order:

  1. JoinOp — equi-join on a key column.

  2. FilterOp — boolean mask applied to all columns.

  3. GroupByOp — group key used for aggregations.

  4. SelectOp — column expressions emitted as outputs.

ONNX operations used#

  • Compress — row-wise filtering (WHERE clause).

  • Gather — index-based row selection (JOIN / GROUP BY key alignment).

  • Add, Sub, Mul, Div — arithmetic expressions.

  • Equal, Less, Greater, LessOrEqual, GreaterOrEqual — comparison predicates.

  • And, Or — compound predicates.

  • ReduceSum, ReduceMean, ReduceMin, ReduceMax — SUM / AVG / MIN / MAX aggregations (global, when no GROUP BY).

  • Unique — extracting distinct group keys for GROUP BY.

  • ScatterElements — per-group accumulation for GROUP BY aggregations.

Limitations#

  • Only equi-joins on a single key column are supported.

  • GROUP BY with SUM, AVG, MIN, MAX, COUNT(*) produces one output row per unique key combination. For multi-column GROUP BY the key columns are internally cast to float64 before grouping, which may lose precision for integers larger than 2^53.

  • SELECT DISTINCT is not yet supported and raises NotImplementedError.