Merge pull request #173 from alex-dukhno/create-schema

Support `CREATE SCHEMA schema_name` and `DROP SCHEMA schema_name`.

Both ANSI SQL and Posgres define a number of options for the CREATE SCHEMA statement.
They also support including other CREATE statements as part of the schema definition,
rather than separate statements. This PR supports neither.

src/ast/mod.rs

@@ -535,6 +535,8 @@ pub enum Statement {
     Commit { chain: bool },
     /// `ROLLBACK [ TRANSACTION | WORK ] [ AND [ NO ] CHAIN ]`
     Rollback { chain: bool },
+    /// CREATE SCHEMA
+    CreateSchema { schema_name: ObjectName },
 }
 
 impl fmt::Display for Statement {
@@ -754,6 +756,7 @@ impl fmt::Display for Statement {
             Statement::Rollback { chain } => {
                 write!(f, "ROLLBACK{}", if *chain { " AND CHAIN" } else { "" },)
             }
+            Statement::CreateSchema { schema_name } => write!(f, "CREATE SCHEMA {}", schema_name),
         }
     }
 }
@@ -852,6 +855,7 @@ pub enum ObjectType {
     Table,
     View,
     Index,
+    Schema,
 }
 
 impl fmt::Display for ObjectType {
@@ -860,6 +864,7 @@ impl fmt::Display for ObjectType {
             ObjectType::Table => "TABLE",
             ObjectType::View => "VIEW",
             ObjectType::Index => "INDEX",
+            ObjectType::Schema => "SCHEMA",
         })
     }
 }

src/dialect/keywords.rs

@@ -330,6 +330,7 @@ define_keywords!(
     ROW_NUMBER,
     ROWS,
     SAVEPOINT,
+    SCHEMA,
     SCOPE,
     SCROLL,
     SEARCH,

src/parser.rs

@@ -864,11 +864,21 @@ impl Parser {
             self.parse_create_view()
         } else if self.parse_keyword("EXTERNAL") {
             self.parse_create_external_table()
+        } else if self.parse_keyword("SCHEMA") {
+            self.parse_create_schema()
         } else {
-            self.expected("TABLE, VIEW or INDEX after CREATE", self.peek_token())
+            self.expected(
+                "TABLE, VIEW, INDEX or SCHEMA after CREATE",
+                self.peek_token(),
+            )
         }
     }
 
+    pub fn parse_create_schema(&mut self) -> Result<Statement, ParserError> {
+        let schema_name = self.parse_object_name()?;
+        Ok(Statement::CreateSchema { schema_name })
+    }
+
     pub fn parse_create_external_table(&mut self) -> Result<Statement, ParserError> {
         self.expect_keyword("TABLE")?;
         let table_name = self.parse_object_name()?;
@@ -918,8 +928,10 @@ impl Parser {
             ObjectType::View
         } else if self.parse_keyword("INDEX") {
             ObjectType::Index
+        } else if self.parse_keyword("SCHEMA") {
+            ObjectType::Schema
         } else {
-            return self.expected("TABLE, VIEW or INDEX after DROP", self.peek_token());
+            return self.expected("TABLE, VIEW, INDEX or SCHEMA after DROP", self.peek_token());
         };
         // Many dialects support the non standard `IF EXISTS` clause and allow
         // specifying multiple objects to delete in a single statement

tests/sqlparser_common.rs

@@ -1027,6 +1027,28 @@ fn parse_create_table_with_multiple_on_delete_fails() {
     .expect_err("should have failed");
 }
 
+#[test]
+fn parse_create_schema() {
+    let sql = "CREATE SCHEMA X";
+
+    match verified_stmt(sql) {
+        Statement::CreateSchema { schema_name } => {
+            assert_eq!(schema_name.to_string(), "X".to_owned())
+        }
+        _ => unreachable!(),
+    }
+}
+
+#[test]
+fn parse_drop_schema() {
+    let sql = "DROP SCHEMA X";
+
+    match verified_stmt(sql) {
+        Statement::Drop { object_type, .. } => assert_eq!(object_type, ObjectType::Schema),
+        _ => unreachable!(),
+    }
+}
+
 #[test]
 fn parse_create_table_with_on_delete_on_update_2in_any_order() -> Result<(), ParserError> {
     let sql = |options: &str| -> String {