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snowflake_flatten_projection_to_unnest

polyglot_sql::transforms

Function snowflake_flatten_projection_to_unnest 

Source 
pub fn snowflake_flatten_projection_to_unnest(
    expr: Expression,
) -> Result<Expression>
Expand description

Snowflake-specific rewrite to mirror Python sqlglot’s explode_projection_to_unnest behavior when FLATTEN appears in a nested LATERAL within a SELECT projection.

This intentionally rewrites:

  • LATERAL FLATTEN(INPUT => x) alias into:
  • LATERAL IFF(_u.pos = _u_2.pos_2, _u_2.entity, NULL) AS alias(SEQ, KEY, PATH, INDEX, VALUE, THIS) and appends CROSS JOIN TABLE(FLATTEN(…)) range/entity joins plus alignment predicates to the containing SELECT.