Support nested expressions in BETWEEN

`BETWEEN <thing> AND <thing>` allows <thing> to be any expr that doesn't
contain boolean operators. (Allowing boolean operators would wreak
havoc, because of the repurposing of AND as both a boolean operation
and part of the syntax of BETWEEN.)

Author: benesch

src/sqlparser.rs

@@ -478,9 +478,10 @@ impl Parser {
 
     /// Parses `BETWEEN <low> AND <high>`, assuming the `BETWEEN` keyword was already consumed
     pub fn parse_between(&mut self, expr: ASTNode, negated: bool) -> Result<ASTNode, ParserError> {
-        let low = self.parse_prefix()?;
+        let prec = self.get_precedence(&Token::make_keyword("BETWEEN"))?;
+        let low = self.parse_subexpr(prec)?;
         self.expect_keyword("AND")?;
-        let high = self.parse_prefix()?;
+        let high = self.parse_subexpr(prec)?;
         Ok(ASTNode::SQLBetween {
             expr: Box::new(expr),
             negated,

tests/sqlparser_common.rs

@@ -450,6 +450,33 @@ fn parse_between() {
     chk(true);
 }
 
+#[test]
+fn parse_between_with_expr() {
+    use self::ASTNode::*;
+    use self::SQLOperator::*;
+    let sql = "SELECT * FROM t WHERE 1 BETWEEN 1 + 2 AND 3 + 4 IS NULL";
+    let select = verified_only_select(sql);
+    let low = SQLBinaryExpr {
+        left: Box::new(ASTNode::SQLValue(Value::Long(1))),
+        op: Plus,
+        right: Box::new(ASTNode::SQLValue(Value::Long(2))),
+    };
+    let high = SQLBinaryExpr {
+        left: Box::new(ASTNode::SQLValue(Value::Long(3))),
+        op: Plus,
+        right: Box::new(ASTNode::SQLValue(Value::Long(4))),
+    };
+    assert_eq!(
+        ASTNode::SQLIsNull(Box::new(ASTNode::SQLBetween {
+            expr: Box::new(ASTNode::SQLValue(Value::Long(1))),
+            low: Box::new(low),
+            high: Box::new(high),
+            negated: false,
+        })),
+        select.selection.unwrap()
+    );
+}
+
 #[test]
 fn parse_select_order_by() {
     fn chk(sql: &str) {