implement NOT

src/sqlast/sql_operator.rs

@@ -14,6 +14,7 @@ pub enum SQLOperator {
     NotEq,
     And,
     Or,
+    Not,
     Like,
 }
 
@@ -33,6 +34,7 @@ impl ToString for SQLOperator {
             SQLOperator::NotEq => "!=".to_string(),
             SQLOperator::And => "AND".to_string(),
             SQLOperator::Or => "OR".to_string(),
+            SQLOperator::Not => "NOT".to_string(),
             SQLOperator::Like => "LIKE".to_string(),
         }
     }

src/sqlparser.rs

@@ -108,6 +108,10 @@ impl Parser {
                         self.parse_sql_value()
                     }
                     "CASE" => self.parse_case_expression(),
+                    "NOT" => Ok(ASTNode::SQLUnary {
+                        operator: SQLOperator::Not,
+                        rex: Box::new(self.parse_expr(0)?),
+                    }),
                     _ => return parser_err!(format!("No prefix parser for keyword {}", k)),
                 },
                 Token::Mult => Ok(ASTNode::SQLWildcard),
@@ -329,6 +333,7 @@ impl Parser {
             &Token::Mod => Ok(SQLOperator::Modulus),
             &Token::Keyword(ref k) if k == "AND" => Ok(SQLOperator::And),
             &Token::Keyword(ref k) if k == "OR" => Ok(SQLOperator::Or),
+            &Token::Keyword(ref k) if k == "NOT" => Ok(SQLOperator::Not),
             &Token::Keyword(ref k) if k == "LIKE" => Ok(SQLOperator::Like),
             _ => parser_err!(format!("Unsupported SQL operator {:?}", tok)),
         }

tests/sqlparser_generic.rs

@@ -105,6 +105,16 @@ fn parse_select_count_wildcard() {
     }
 }
 
+#[test]
+fn parse_not() {
+    let sql = String::from(
+        "SELECT id FROM customer \
+         WHERE NOT salary = ''",
+    );
+    let _ast = parse_sql(&sql);
+    //TODO: add assertions
+}
+
 #[test]
 fn parse_select_string_predicate() {
     let sql = String::from(