feat: return error while encountering unsupport from in influxql (#745)

* return error while encountering unsupport from in influxql.

* address CR.

Author: Rachelint

sql/src/influxql/mod.rs

@@ -19,11 +19,22 @@ pub mod error {
         ))]
         BuildSchema { msg: String, backtrace: Backtrace },
 
-        #[snafu(display("Failed to build influxql plan, msg:{}, err:{}", msg, source))]
-        BuildPlan { msg: String, source: GenericError },
+        #[snafu(display(
+            "Failed to build influxql plan with cause, msg:{}, err:{}",
+            msg,
+            source
+        ))]
+        BuildPlanWithCause { msg: String, source: GenericError },
+
+        #[snafu(display(
+            "Failed to build influxql plan with no cause, msg:{}.\nBacktrace:{}",
+            msg,
+            backtrace
+        ))]
+        BuildPlanNoCause { msg: String, backtrace: Backtrace },
 
-        #[snafu(display("Unimplemented influxql statement, statement:{}", stmt))]
-        Unimplemented { stmt: String },
+        #[snafu(display("Unimplemented influxql statement, msg:{}", msg))]
+        Unimplemented { msg: String },
     }
     define_result!(Error);
 }

sql/src/influxql/planner.rs

@@ -6,8 +6,12 @@ use std::sync::Arc;
 
 use common_util::error::BoxError;
 use influxql_logical_planner::planner::InfluxQLToLogicalPlan;
-use influxql_parser::statement::Statement as InfluxqlStatement;
-use snafu::ResultExt;
+use influxql_parser::{
+    common::{MeasurementName, QualifiedMeasurementName},
+    select::{MeasurementSelection, SelectStatement},
+    statement::Statement as InfluxqlStatement,
+};
+use snafu::{ensure, ResultExt};
 
 use crate::{
     influxql::{error::*, provider::InfluxSchemaProviderImpl},
@@ -44,13 +48,19 @@ impl<'a, P: MetaProvider> Planner<'a, P> {
             | InfluxqlStatement::Delete(_)
             | InfluxqlStatement::DropMeasurement(_)
             | InfluxqlStatement::Explain(_) => Unimplemented {
-                stmt: stmt.to_string(),
+                msg: stmt.to_string(),
             }
             .fail(),
         }
     }
 
     pub fn select_to_plan(self, stmt: InfluxqlStatement) -> Result<Plan> {
+        if let InfluxqlStatement::Select(select_stmt) = &stmt {
+            check_select_statement(select_stmt)?;
+        } else {
+            unreachable!("select statement here has been ensured by caller");
+        }
+
         let influx_schema_provider = InfluxSchemaProviderImpl {
             context_provider: &self.context_provider,
         };
@@ -62,18 +72,94 @@ impl<'a, P: MetaProvider> Planner<'a, P> {
         let df_plan = influxql_logical_planner
             .statement_to_plan(stmt)
             .box_err()
-            .context(BuildPlan {
+            .context(BuildPlanWithCause {
                 msg: "build df plan for influxql select statement",
             })?;
         let tables = Arc::new(
             self.context_provider
                 .try_into_container()
                 .box_err()
-                .context(BuildPlan {
+                .context(BuildPlanWithCause {
                     msg: "get tables from df plan of select",
                 })?,
         );
 
         Ok(Plan::Query(QueryPlan { df_plan, tables }))
     }
 }
+
+pub fn check_select_statement(select_stmt: &SelectStatement) -> Result<()> {
+    // Only support from single measurements now.
+    ensure!(
+        !select_stmt.from.is_empty(),
+        BuildPlanNoCause {
+            msg: format!("invalid influxql select statement with empty from, stmt:{select_stmt}"),
+        }
+    );
+    ensure!(
+        select_stmt.from.len() == 1,
+        Unimplemented {
+            msg: format!("select from multiple measurements, stmt:{select_stmt}"),
+        }
+    );
+
+    let from = &select_stmt.from[0];
+    match from {
+        MeasurementSelection::Name(name) => {
+            let QualifiedMeasurementName { name, .. } = name;
+
+            match name {
+                MeasurementName::Regex(_) => Unimplemented {
+                    msg: format!("select from regex, stmt:{select_stmt}"),
+                }
+                .fail(),
+                MeasurementName::Name(_) => Ok(()),
+            }
+        }
+        MeasurementSelection::Subquery(_) => Unimplemented {
+            msg: format!("select from subquery, stmt:{select_stmt}"),
+        }
+        .fail(),
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use influxql_parser::{select::SelectStatement, statement::Statement};
+
+    use super::check_select_statement;
+
+    #[test]
+    fn test_check_select_from() {
+        let from_measurement = parse_select("select * from a;");
+        let from_multi_measurements = parse_select("select * from a,b;");
+        let from_regex = parse_select(r#"select * from /d/"#);
+        let from_subquery = parse_select("select * from (select a,b from c)");
+
+        let res = check_select_statement(&from_measurement);
+        assert!(res.is_ok());
+
+        let res = check_select_statement(&from_multi_measurements);
+        let err = res.err().unwrap();
+        assert!(err
+            .to_string()
+            .contains("select from multiple measurements"));
+
+        let res = check_select_statement(&from_regex);
+        let err = res.err().unwrap();
+        assert!(err.to_string().contains("select from regex"));
+
+        let res = check_select_statement(&from_subquery);
+        let err = res.err().unwrap();
+        assert!(err.to_string().contains("select from subquery"));
+    }
+
+    fn parse_select(influxql: &str) -> SelectStatement {
+        let stmt = influxql_parser::parse_statements(influxql).unwrap()[0].clone();
+        if let Statement::Select(select_stmt) = stmt {
+            *select_stmt
+        } else {
+            unreachable!()
+        }
+    }
+}