delete: add using clause, possibility of using aliases (apache#541)

Signed-off-by: Maciej Obuchowski <obuchowski.maciej@gmail.com>

Author: mobuchowski

src/ast/mod.rs

@@ -830,7 +830,9 @@ pub enum Statement {
     /// DELETE
     Delete {
         /// FROM
-        table_name: ObjectName,
+        table_name: TableFactor,
+        /// USING (Snowflake, Postgres)
+        using: Option<TableFactor>,
         /// WHERE
         selection: Option<Expr>,
     },
@@ -1398,9 +1400,13 @@ impl fmt::Display for Statement {
             }
             Statement::Delete {
                 table_name,
+                using,
                 selection,
             } => {
                 write!(f, "DELETE FROM {}", table_name)?;
+                if let Some(using) = using {
+                    write!(f, " USING {}", using)?;
+                }
                 if let Some(selection) = selection {
                     write!(f, " WHERE {}", selection)?;
                 }

src/parser.rs

@@ -3141,7 +3141,12 @@ impl<'a> Parser<'a> {
 
     pub fn parse_delete(&mut self) -> Result<Statement, ParserError> {
         self.expect_keyword(Keyword::FROM)?;
-        let table_name = self.parse_object_name()?;
+        let table_name = self.parse_table_factor()?;
+        let using = if self.parse_keyword(Keyword::USING) {
+            Some(self.parse_table_factor()?)
+        } else {
+            None
+        };
         let selection = if self.parse_keyword(Keyword::WHERE) {
             Some(self.parse_expr()?)
         } else {
@@ -3150,6 +3155,7 @@ impl<'a> Parser<'a> {
 
         Ok(Statement::Delete {
             table_name,
+            using,
             selection,
         })
     }

tests/sqlparser_common.rs

@@ -253,7 +253,12 @@ fn parse_delete_statement() {
     match verified_stmt(sql) {
         Statement::Delete { table_name, .. } => {
             assert_eq!(
-                ObjectName(vec![Ident::with_quote('"', "table")]),
+                TableFactor::Table {
+                    name: ObjectName(vec![Ident::with_quote('"', "table")]),
+                    alias: None,
+                    args: None,
+                    with_hints: vec![]
+                },
                 table_name
             );
         }
@@ -269,11 +274,20 @@ fn parse_where_delete_statement() {
     match verified_stmt(sql) {
         Statement::Delete {
             table_name,
+            using,
             selection,
-            ..
         } => {
-            assert_eq!(ObjectName(vec![Ident::new("foo")]), table_name);
+            assert_eq!(
+                TableFactor::Table {
+                    name: ObjectName(vec![Ident::new("foo")]),
+                    alias: None,
+                    args: None,
+                    with_hints: vec![]
+                },
+                table_name,
+            );
 
+            assert_eq!(None, using);
             assert_eq!(
                 Expr::BinaryOp {
                     left: Box::new(Expr::Identifier(Ident::new("name"))),
@@ -287,6 +301,61 @@ fn parse_where_delete_statement() {
     }
 }
 
+#[test]
+fn parse_where_delete_with_alias_statement() {
+    use self::BinaryOperator::*;
+
+    let sql = "DELETE FROM basket AS a USING basket AS b WHERE a.id < b.id";
+    match verified_stmt(sql) {
+        Statement::Delete {
+            table_name,
+            using,
+            selection,
+        } => {
+            assert_eq!(
+                TableFactor::Table {
+                    name: ObjectName(vec![Ident::new("basket")]),
+                    alias: Some(TableAlias {
+                        name: Ident::new("a"),
+                        columns: vec![]
+                    }),
+                    args: None,
+                    with_hints: vec![]
+                },
+                table_name,
+            );
+
+            assert_eq!(
+                Some(TableFactor::Table {
+                    name: ObjectName(vec![Ident::new("basket")]),
+                    alias: Some(TableAlias {
+                        name: Ident::new("b"),
+                        columns: vec![]
+                    }),
+                    args: None,
+                    with_hints: vec![]
+                }),
+                using
+            );
+            assert_eq!(
+                Expr::BinaryOp {
+                    left: Box::new(Expr::CompoundIdentifier(vec![
+                        Ident::new("a"),
+                        Ident::new("id")
+                    ])),
+                    op: Lt,
+                    right: Box::new(Expr::CompoundIdentifier(vec![
+                        Ident::new("b"),
+                        Ident::new("id")
+                    ])),
+                },
+                selection.unwrap(),
+            );
+        }
+        _ => unreachable!(),
+    }
+}
+
 #[test]
 fn parse_top_level() {
     verified_stmt("SELECT 1");