Support DROP DATABASE (#1443)

Author: linhr

src/ast/mod.rs

@@ -5691,6 +5691,7 @@ pub enum ObjectType {
     View,
     Index,
     Schema,
+    Database,
     Role,
     Sequence,
     Stage,
@@ -5703,6 +5704,7 @@ impl fmt::Display for ObjectType {
             ObjectType::View => "VIEW",
             ObjectType::Index => "INDEX",
             ObjectType::Schema => "SCHEMA",
+            ObjectType::Database => "DATABASE",
             ObjectType::Role => "ROLE",
             ObjectType::Sequence => "SEQUENCE",
             ObjectType::Stage => "STAGE",

src/parser/mod.rs

@@ -4881,6 +4881,8 @@ impl<'a> Parser<'a> {
             ObjectType::Role
         } else if self.parse_keyword(Keyword::SCHEMA) {
             ObjectType::Schema
+        } else if self.parse_keyword(Keyword::DATABASE) {
+            ObjectType::Database
         } else if self.parse_keyword(Keyword::SEQUENCE) {
             ObjectType::Sequence
         } else if self.parse_keyword(Keyword::STAGE) {
@@ -4897,7 +4899,7 @@ impl<'a> Parser<'a> {
             return self.parse_drop_trigger();
         } else {
             return self.expected(
-                "TABLE, VIEW, INDEX, ROLE, SCHEMA, FUNCTION, PROCEDURE, STAGE, TRIGGER, SECRET or SEQUENCE after DROP",
+                "TABLE, VIEW, INDEX, ROLE, SCHEMA, DATABASE, FUNCTION, PROCEDURE, STAGE, TRIGGER, SECRET or SEQUENCE after DROP",
                 self.peek_token(),
             );
         };

tests/sqlparser_common.rs

@@ -6734,6 +6734,43 @@ fn parse_create_database_ine() {
     }
 }
 
+#[test]
+fn parse_drop_database() {
+    let sql = "DROP DATABASE mycatalog.mydb";
+    match verified_stmt(sql) {
+        Statement::Drop {
+            names,
+            object_type,
+            if_exists,
+            ..
+        } => {
+            assert_eq!(
+                vec!["mycatalog.mydb"],
+                names.iter().map(ToString::to_string).collect::<Vec<_>>()
+            );
+            assert_eq!(ObjectType::Database, object_type);
+            assert!(!if_exists);
+        }
+        _ => unreachable!(),
+    }
+}
+
+#[test]
+fn parse_drop_database_if_exists() {
+    let sql = "DROP DATABASE IF EXISTS mydb";
+    match verified_stmt(sql) {
+        Statement::Drop {
+            object_type,
+            if_exists,
+            ..
+        } => {
+            assert_eq!(ObjectType::Database, object_type);
+            assert!(if_exists);
+        }
+        _ => unreachable!(),
+    }
+}
+
 #[test]
 fn parse_create_view() {
     let sql = "CREATE VIEW myschema.myview AS SELECT foo FROM bar";