From 14c5e3f1e512f19fe4c327126b9467655947ca51 Mon Sep 17 00:00:00 2001
From: Jens Schauder <jschauder@vmware.com>
Date: Wed, 2 Feb 2022 15:29:57 +0100
Subject: [PATCH] Render windowing functions without arguments correctly.

Closes #1153
See #1019
---
 .../core/sql/render/SimpleFunctionVisitor.java    |  7 ++-----
 .../core/sql/render/SelectRendererUnitTests.java  | 15 +++++++++++++++
 2 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/spring-data-relational/src/main/java/org/springframework/data/relational/core/sql/render/SimpleFunctionVisitor.java b/spring-data-relational/src/main/java/org/springframework/data/relational/core/sql/render/SimpleFunctionVisitor.java
index a3e3da3b..6b6125c5 100644
--- a/spring-data-relational/src/main/java/org/springframework/data/relational/core/sql/render/SimpleFunctionVisitor.java
+++ b/spring-data-relational/src/main/java/org/springframework/data/relational/core/sql/render/SimpleFunctionVisitor.java
@@ -30,7 +30,6 @@ class SimpleFunctionVisitor extends TypedSingleConditionRenderSupport<SimpleFunc
 
 	private final StringBuilder part = new StringBuilder();
 	private boolean needsComma = false;
-	private String functionName;
 
 	SimpleFunctionVisitor(RenderContext context) {
 		super(context);
@@ -45,9 +44,6 @@ class SimpleFunctionVisitor extends TypedSingleConditionRenderSupport<SimpleFunc
 				part.append(", ");
 			}
 
-			if (part.length() == 0) {
-				part.append(functionName).append("(");
-			}
 			part.append(consumeRenderedPart());
 			needsComma = true;
 		}
@@ -58,7 +54,8 @@ class SimpleFunctionVisitor extends TypedSingleConditionRenderSupport<SimpleFunc
 	@Override
 	Delegation enterMatched(SimpleFunction segment) {
 
-		functionName = segment.getFunctionName();
+		part.append(segment.getFunctionName()).append("(");
+
 		return super.enterMatched(segment);
 	}
 
diff --git a/spring-data-relational/src/test/java/org/springframework/data/relational/core/sql/render/SelectRendererUnitTests.java b/spring-data-relational/src/test/java/org/springframework/data/relational/core/sql/render/SelectRendererUnitTests.java
index 5904f300..093c2513 100644
--- a/spring-data-relational/src/test/java/org/springframework/data/relational/core/sql/render/SelectRendererUnitTests.java
+++ b/spring-data-relational/src/test/java/org/springframework/data/relational/core/sql/render/SelectRendererUnitTests.java
@@ -663,5 +663,20 @@ class SelectRendererUnitTests {
 			assertThat(rendered).isEqualTo(
 					"SELECT MAX(employee.salary) OVER(PARTITION BY employee.department ORDER BY employee.age) AS MAX_SELECT FROM employee");
 		}
+
+		@Test // GH-1153
+		void renderAnalyticFunctionWithOutArgument() {
+
+			final Select select = StatementBuilder.select( //
+					AnalyticFunction.create("ROW_NUMBER") //
+							.partitionBy(department)) //
+					.from(employee) //
+					.build();
+
+			String rendered = SqlRenderer.toString(select);
+
+			assertThat(rendered).isEqualTo(
+					"SELECT ROW_NUMBER() OVER(PARTITION BY employee.department) FROM employee");
+		}
 	}
 }