feat(cubesql): Execute SHOW DATABASES from AST

cube-js · Nov 2, 2021 · cd2b4ac · cd2b4ac
1 parent da96a22
commit cd2b4ac
Show file tree

Hide file tree

Showing 2 changed files with 31 additions and 29 deletions.
diff --git a/rust/cubesql/src/compile/mod.rs b/rust/cubesql/src/compile/mod.rs
@@ -10,7 +10,7 @@ use datafusion::{logical_plan::LogicalPlan, prelude::*};
 use log::{debug, trace};
 use serde::Serialize;
 use serde_json::json;
-use sqlparser::ast;
+use sqlparser::ast::{self, Ident, ObjectName};
 use sqlparser::parser::Parser;
 
 use cubeclient::models::{
@@ -1009,6 +1009,9 @@ impl QueryPlanner {
                     vec![],
                 ))));
             }
+            ast::Statement::ShowVariable { variable } => {
+                return self.show_variable_to_plan(&variable);
+            }
             // Proxy some queries to DF
             ast::Statement::ShowColumns { .. } | ast::Statement::ShowVariable { .. } => {
                 return self.create_df_logical_plan(stmt.clone());
@@ -1124,6 +1127,33 @@ impl QueryPlanner {
         }
     }
 
+    fn show_variable_to_plan(&self, variable: &Vec<Ident>) -> CompilationResult<QueryPlan> {
+        let name = ObjectName(variable.to_vec()).to_string();
+        if name.eq_ignore_ascii_case("databases") || name.eq_ignore_ascii_case("schemas") {
+            return Ok(QueryPlan::Meta(Arc::new(dataframe::DataFrame::new(
+                vec![dataframe::Column::new(
+                    "Database".to_string(),
+                    ColumnType::MYSQL_TYPE_STRING,
+                )],
+                vec![
+                    dataframe::Row::new(vec![dataframe::TableValue::String("db".to_string())]),
+                    dataframe::Row::new(vec![dataframe::TableValue::String(
+                        "information_schema".to_string(),
+                    )]),
+                    dataframe::Row::new(vec![dataframe::TableValue::String("mysql".to_string())]),
+                    dataframe::Row::new(vec![dataframe::TableValue::String(
+                        "performance_schema".to_string(),
+                    )]),
+                    dataframe::Row::new(vec![dataframe::TableValue::String("sys".to_string())]),
+                ],
+            ))));
+        } else {
+            return self.create_df_logical_plan(ast::Statement::ShowVariable {
+                variable: variable.clone(),
+            });
+        }
+    }
+
     fn create_df_logical_plan(&self, stmt: ast::Statement) -> CompilationResult<QueryPlan> {
         let mut ctx = ExecutionContext::new();
 

diff --git a/rust/cubesql/src/mysql/mod.rs b/rust/cubesql/src/mysql/mod.rs
@@ -183,34 +183,6 @@ impl Backend {
                     )
                 ),
             )
-        } else if query_lower.eq("show schemas") || query_lower.eq("show databases") {
-            return Ok(
-                Arc::new(
-                    dataframe::DataFrame::new(
-                        vec![dataframe::Column::new(
-                            "Database".to_string(),
-                            ColumnType::MYSQL_TYPE_STRING,
-                        )],
-                        vec![
-                            dataframe::Row::new(vec![
-                                dataframe::TableValue::String("db".to_string())
-                            ]),
-                            dataframe::Row::new(vec![
-                                dataframe::TableValue::String("information_schema".to_string())
-                            ]),
-                            dataframe::Row::new(vec![
-                                dataframe::TableValue::String("mysql".to_string())
-                            ]),
-                            dataframe::Row::new(vec![
-                                dataframe::TableValue::String("performance_schema".to_string())
-                            ]),
-                            dataframe::Row::new(vec![
-                                dataframe::TableValue::String("sys".to_string())
-                            ])
-                        ]
-                    )
-                ),
-            )
         } else if query_lower.eq("select connection_id()") {
             return Ok(
                 Arc::new(