wqc200 commented on a change in pull request #8033:
URL: https://github.com/apache/arrow/pull/8033#discussion_r476572025
##########
File path: rust/datafusion/src/variable/system.rs
##########
@@ -0,0 +1,18 @@
+use crate::logicalplan::ScalarValue;
+use crate::error::Result;
+use crate::variable::VariableProvider;
+
+pub struct SystemVariable {}
+
+impl SystemVariable {
+ pub fn new() -> Self {
+ Self {}
+ }
+}
+
+impl VariableProvider for SystemVariable {
+ fn get_value(&self, variable_names: Vec<String>) -> Result<ScalarValue> {
+ let s = format!("{}-{}", "test".to_string(), variable_names.concat());
Review comment:
When the user USES, to create a new system and user_defined method, here
is only for the user to understand.
The @@ variable is defined by the external system
----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
For queries about this service, please contact Infrastructure at:
us...@infra.apache.org
