alamb commented on a change in pull request #1067:
URL: https://github.com/apache/arrow-datafusion/pull/1067#discussion_r724335933
##########
File path: datafusion/src/execution/context.rs
##########
@@ -2090,7 +2090,7 @@ mod tests {
let results = plan_and_collect(
&mut ctx,
"SELECT * FROM t as t1 \
- JOIN (SELECT * FROM t as t2) \
+ JOIN (SELECT * FROM t) as t2 \
Review comment:
👍
##########
File path: datafusion/src/logical_plan/builder.rs
##########
@@ -231,34 +231,26 @@ impl LogicalPlanBuilder {
Ok(Self::from(table_scan))
}
- /// Apply a projection.
- ///
- /// # Errors
- /// This function errors under any of the following conditions:
- /// * Two or more expressions have the same name
- /// * An invalid expression is used (e.g. a `sort` expression)
+ /// Apply a projection without alias.
pub fn project(&self, expr: impl IntoIterator<Item = Expr>) ->
Result<Self> {
- let input_schema = self.plan.schema();
- let mut projected_expr = vec![];
- for e in expr {
- match e {
- Expr::Wildcard => {
- projected_expr.extend(expand_wildcard(input_schema,
&self.plan)?)
- }
- _ => projected_expr
- .push(columnize_expr(normalize_col(e, &self.plan)?,
input_schema)),
- }
- }
-
- validate_unique_names("Projections", projected_expr.iter(),
input_schema)?;
-
- let schema = DFSchema::new(exprlist_to_fields(&projected_expr,
input_schema)?)?;
+ Ok(Self::from(project_with_alias(
Review comment:
I wonder if you could write this like `self.project_with_alias(expr,
None)` which might be slightly cleaner
##########
File path: datafusion/src/logical_plan/builder.rs
##########
@@ -610,6 +599,41 @@ pub fn union_with_alias(
})
}
+/// Project with optional alias
+/// # Errors
+/// This function errors under any of the following conditions:
+/// * Two or more expressions have the same name
+/// * An invalid expression is used (e.g. a `sort` expression)
+pub fn project_with_alias(
+ plan: LogicalPlan,
+ expr: impl IntoIterator<Item = Expr>,
+ alias: Option<String>,
+) -> Result<LogicalPlan> {
+ let input_schema = plan.schema();
+ let mut projected_expr = vec![];
+ for e in expr {
+ match e {
+ Expr::Wildcard => {
+ projected_expr.extend(expand_wildcard(input_schema, &plan)?)
+ }
+ _ => projected_expr
+ .push(columnize_expr(normalize_col(e, &plan)?, input_schema)),
+ }
+ }
+ validate_unique_names("Projections", projected_expr.iter(), input_schema)?;
+ let input_schema = DFSchema::new(exprlist_to_fields(&projected_expr,
input_schema)?)?;
+ let schema = match alias {
+ Some(ref alias) => input_schema.replace_qualifier(alias.as_str()),
+ None => input_schema,
+ };
+ Ok(LogicalPlan::Projection {
Review comment:
👍
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