Function datafusion_expr::utils::columnize_expr

pub fn columnize_expr(e: Expr, input_schema: &DFSchema) -> Expr

Convert an expression into Column expression if it’s already provided as input plan.

For example, it rewrites:

.aggregate(vec![col("c1")], vec![sum(col("c2"))])?
.project(vec![col("c1"), sum(col("c2"))?

Into:

.aggregate(vec![col("c1")], vec![sum(col("c2"))])?
.project(vec![col("c1"), col("SUM(#c2)")?