From 0b92277de43723c688af3b34ce14a047b641cb9c Mon Sep 17 00:00:00 2001
From: Dylan <chenzl25@mail2.sysu.edu.cn>
Date: Wed, 10 Apr 2024 15:56:13 +0800
Subject: [PATCH] fix(binder): fix user keyword (#16229)

---
 e2e_test/batch/keyword/user.slt     | 16 ++++++++++++++++
 src/frontend/src/binder/expr/mod.rs |  2 +-
 src/sqlparser/src/ast/mod.rs        |  4 ++++
 3 files changed, 21 insertions(+), 1 deletion(-)
 create mode 100644 e2e_test/batch/keyword/user.slt

diff --git a/e2e_test/batch/keyword/user.slt b/e2e_test/batch/keyword/user.slt
new file mode 100644
index 0000000000000..353e7f026e6e6
--- /dev/null
+++ b/e2e_test/batch/keyword/user.slt
@@ -0,0 +1,16 @@
+statement ok
+SET RW_IMPLICIT_FLUSH TO true;
+
+statement ok
+create table t (id int, user varchar);
+
+statement ok
+insert into t values (1, 'abc');
+
+query I
+select id, "user", 'user', user = current_user from t;
+----
+1 abc user t
+
+statement ok
+drop table t;
\ No newline at end of file
diff --git a/src/frontend/src/binder/expr/mod.rs b/src/frontend/src/binder/expr/mod.rs
index e0f0892a03db9..0b8b50be0eab6 100644
--- a/src/frontend/src/binder/expr/mod.rs
+++ b/src/frontend/src/binder/expr/mod.rs
@@ -74,7 +74,7 @@ impl Binder {
             Expr::Identifier(ident) => {
                 if SYS_FUNCTION_WITHOUT_ARGS
                     .iter()
-                    .any(|e| ident.real_value().as_str() == *e)
+                    .any(|e| ident.real_value().as_str() == *e && ident.quote_style().is_none())
                 {
                     // Rewrite a system variable to a function call, e.g. `SELECT current_schema;`
                     // will be rewritten to `SELECT current_schema();`.
diff --git a/src/sqlparser/src/ast/mod.rs b/src/sqlparser/src/ast/mod.rs
index 97cfe41eac320..825418e75ccc5 100644
--- a/src/sqlparser/src/ast/mod.rs
+++ b/src/sqlparser/src/ast/mod.rs
@@ -167,6 +167,10 @@ impl Ident {
             _ => self.value.to_lowercase(),
         }
     }
+
+    pub fn quote_style(&self) -> Option<char> {
+        self.quote_style
+    }
 }
 
 impl From<&str> for Ident {