Support $$ as placeholder name in SQLite dialect

Author: hansott

src/tokenizer.rs

@@ -43,7 +43,7 @@ use sqlparser_derive::{Visit, VisitMut};
 use crate::ast::DollarQuotedString;
 use crate::dialect::Dialect;
 use crate::dialect::{
-    BigQueryDialect, DuckDbDialect, GenericDialect, MySqlDialect, PostgreSqlDialect,
+    BigQueryDialect, DuckDbDialect, GenericDialect, MySqlDialect, PostgreSqlDialect, SQLiteDialect,
     SnowflakeDialect,
 };
 use crate::keywords::{Keyword, ALL_KEYWORDS, ALL_KEYWORDS_INDEX};
@@ -1281,6 +1281,12 @@ impl<'a> Tokenizer<'a> {
         if let Some('$') = chars.peek() {
             chars.next();
 
+            // Treat `$$` as a placeholder for SQLite
+            // See https://www.sqlite.org/lang_expr.html#varparam
+            if self.dialect.is::<SQLiteDialect>() {
+                return Ok(Token::Placeholder("$$".to_string()));
+            }
+
             let mut is_terminated = false;
             let mut prev: Option<char> = None;
 

tests/sqlparser_sqlite.rs

@@ -568,6 +568,15 @@ fn test_dollar_identifier_as_placeholder() {
         }
         _ => unreachable!(),
     }
+
+    match sqlite().verified_expr("id = $$") {
+        Expr::BinaryOp { op, left, right } => {
+            assert_eq!(op, BinaryOperator::Eq);
+            assert_eq!(left, Box::new(Expr::Identifier(Ident::new("id"))));
+            assert_eq!(right, Box::new(Expr::Value(Placeholder("$$".to_string()))));
+        }
+        _ => unreachable!(),
+    }
 }
 
 fn sqlite() -> TestedDialects {