datafusion_expr::expr_schema

Function cast_subquery

Source 
pub fn cast_subquery(
    subquery: Subquery,
    cast_to_type: &DataType,
) -> Result<Subquery>
Expand description

Cast subquery in InSubquery/ScalarSubquery to a given type.

  1. Projection plan: If the subquery is a projection (i.e. a SELECT statement with specific columns), it casts the first expression in the projection to the target type and creates a new projection with the casted expression.
  2. Non-projection plan: If the subquery isn’t a projection, it adds a projection to the plan with the casted first column.