From dbe29a105124e4b5befa6114a4f17ac947b2e1e7 Mon Sep 17 00:00:00 2001
From: Vaibhave Sekar <vsekar@microsoft.com>
Date: Mon, 6 Jul 2026 17:27:16 +0000
Subject: [PATCH] positional parameter $n should render as @Pn.

---
 crates/polyglot-sql/src/generator.rs          | 21 ++++++++++++++-----
 .../polyglot-sql/tests/fabric_regression.rs   |  5 +++++
 crates/polyglot-sql/tests/tsql_regression.rs  |  5 +++++
 3 files changed, 26 insertions(+), 5 deletions(-)

diff --git a/crates/polyglot-sql/src/generator.rs b/crates/polyglot-sql/src/generator.rs
index 64600ec..0f83239 100644
--- a/crates/polyglot-sql/src/generator.rs
+++ b/crates/polyglot-sql/src/generator.rs
@@ -22122,12 +22122,23 @@ impl Generator {
         match f.style {
             ParameterStyle::Question => self.write("?"),
             ParameterStyle::Dollar => {
-                self.write("$");
                 if let Some(idx) = f.index {
-                    self.write(&idx.to_string());
-                } else if let Some(ref name) = f.name {
-                    // Session variable like $x or $query_id
-                    self.write(name);
+                    if matches!(
+                        self.config.dialect,
+                        Some(DialectType::TSQL) | Some(DialectType::Fabric)
+                    ) {
+                        self.write("@P");
+                        self.write(&idx.to_string());
+                    } else {
+                        self.write("$");
+                        self.write(&idx.to_string());
+                    }
+                } else {
+                    self.write("$");
+                    if let Some(ref name) = f.name {
+                        // Session variable like $x or $query_id
+                        self.write(name);
+                    }
                 }
             }
             ParameterStyle::DollarBrace => {
diff --git a/crates/polyglot-sql/tests/fabric_regression.rs b/crates/polyglot-sql/tests/fabric_regression.rs
index 20b5d38..17ec7cc 100644
--- a/crates/polyglot-sql/tests/fabric_regression.rs
+++ b/crates/polyglot-sql/tests/fabric_regression.rs
@@ -18,6 +18,11 @@ fn tsql_to_fabric(sql: &str) -> String {
         .expect("expected at least one statement")
 }
 
+#[test]
+fn postgres_positional_parameters_render_as_tsql_style_placeholders_for_fabric() {
+    assert_eq!(pg_to_fabric("SELECT $1, $2"), "SELECT @P1, @P2");
+}
+
 // ---------------------------------------------------------------------------
 // PostgreSQL LATERAL joins -> Fabric APPLY
 // ---------------------------------------------------------------------------
diff --git a/crates/polyglot-sql/tests/tsql_regression.rs b/crates/polyglot-sql/tests/tsql_regression.rs
index c511e3e..a9e7dfd 100644
--- a/crates/polyglot-sql/tests/tsql_regression.rs
+++ b/crates/polyglot-sql/tests/tsql_regression.rs
@@ -135,6 +135,11 @@ fn tsql_max_length_types_parse_generate_and_transpile() {
     assert!(!postgres[0].is_empty());
 }
 
+#[test]
+fn postgres_positional_parameters_render_as_tsql_style_placeholders() {
+    assert_eq!(pg_to_tsql("SELECT $1, $2"), "SELECT @P1, @P2");
+}
+
 #[test]
 fn tsql_datepart_dayofweek_generates_valid_tsql_datepart() {
     let cases = [