Method set_statement_to_plan

datafusion/sql/src/statement.rs:2116–2169

(&self, statement: Set)

    }

    fn set_statement_to_plan(&self, statement: Set) -> Result<LogicalPlan> {
        match statement {
            Set::SingleAssignment {
                scope,
                hivevar,
                variable,
                values,
            } => {
                if scope.is_some() {
                    return not_impl_err!("SET with scope modifiers is not supported");
                }

                if hivevar {
                    return not_impl_err!("SET HIVEVAR is not supported");
                }

                let variable = object_name_to_string(&variable);
                let mut variable_lower = variable.to_lowercase();

                // Map PostgreSQL "timezone" and MySQL "time.zone" aliases to DataFusion's canonical name
                if variable_lower == "timezone" || variable_lower == "time.zone" {
                    variable_lower = "datafusion.execution.time_zone".to_string();
                }

                if values.len() != 1 {
                    return plan_err!("SET only supports single value assignment");
                }

                let value_string = match &values[0] {
                    SQLExpr::Identifier(i) => ident_to_string(i),
                    SQLExpr::Value(v) => match crate::utils::value_to_string(&v.value) {
                        None => {
                            return plan_err!("Unsupported value {:?}", v.value);
                        }
                        Some(s) => s,
                    },
                    SQLExpr::UnaryOp { op, expr } => match op {
                        UnaryOperator::Plus => format!("+{expr}"),
                        UnaryOperator::Minus => format!("-{expr}"),
                        _ => return plan_err!("Unsupported unary op {:?}", op),
                    },
                    _ => return plan_err!("Unsupported expr {:?}", values[0]),
                };

                Ok(LogicalPlan::Statement(PlanStatement::SetVariable(
                    SetVariable {
                        variable: variable_lower,
                        value: value_string,
                    },
                )))
            }
            other => not_impl_err!("SET variant not implemented yet: {other:?}"),
        }
    }

    fn reset_statement_to_plan(&self, statement: ResetStatement) -> Result<LogicalPlan> {
        match statement {