From 28f7974c2bd263146c0ab1f6334f06e2b2585962 Mon Sep 17 00:00:00 2001
From: Renaud Subiger <renaud@subiger.com>
Date: Fri, 25 Mar 2022 11:02:56 +0100
Subject: [PATCH] Supports ORDER BY and LIMIT clauses in both order (#344)

* Add support for ORDER BY and LIMIT clauses in any order

* Fixes failing test
---
 CHANGELOG.md                                  |  1 +
 .../main/antlr4/org/ehrbase/aql/parser/Aql.g4 |  2 +-
 .../aql/parser/AqlToDtoParserTest.java        | 32 ++++++++++++++++++-
 3 files changed, 33 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index eef958bf0..e1da4e303 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,7 @@ Note: version releases in the 0.x.y range may introduce breaking changes.
 ## [unreleased]
 
 ### Added
+- AQL: support `ORDER BY` and `LIMIT [OFFSET]` clauses in any order ([#344](https://github.com/ehrbase/openEHR_SDK/pull/344))
 
 ### Fixed
 
diff --git a/aql/src/main/antlr4/org/ehrbase/aql/parser/Aql.g4 b/aql/src/main/antlr4/org/ehrbase/aql/parser/Aql.g4
index 7876daf91..a1c8f02be 100644
--- a/aql/src/main/antlr4/org/ehrbase/aql/parser/Aql.g4
+++ b/aql/src/main/antlr4/org/ehrbase/aql/parser/Aql.g4
@@ -18,7 +18,7 @@ grammar Aql;
 
 query   :   queryExpr ;
 
-queryExpr : select from (where)? (orderBy)? (limitExpr)? EOF ;
+queryExpr : select from (where)? (orderBy limitExpr? | limitExpr orderBy?)? EOF ;
 
 select
         : SELECT selectExpr
diff --git a/aql/src/test/java/org/ehrbase/aql/parser/AqlToDtoParserTest.java b/aql/src/test/java/org/ehrbase/aql/parser/AqlToDtoParserTest.java
index 96b5d5039..f34d6968b 100644
--- a/aql/src/test/java/org/ehrbase/aql/parser/AqlToDtoParserTest.java
+++ b/aql/src/test/java/org/ehrbase/aql/parser/AqlToDtoParserTest.java
@@ -363,7 +363,8 @@ public void parseAqlLimitOffset() {
         + "limit 50 "
         + "order by e/ehr_id/value ASC ";
 
-    assertThrows(AqlParseException.class, () -> parser.parse(query3));
+    aql = parser.parse(query3);
+    assertEquals(50, aql.getLimit());
 
     var query4 = "select e/ehr_id/value "
         + "from EHR e "
@@ -409,4 +410,33 @@ public void parseWhereClauseWithBoolean() {
     testAql(aql,
         "Select e/ehr_id/value as F1 from EHR e contains OBSERVATION o where o/data[at0001]/items[at0024]/items[at0025]/value/value != false");
   }
+
+  @Test
+  public void orderByAndLimitOrder() {
+    var aql1 = "Select "
+        + "c/name/value as Name, c/context/start_time as date_time, c/composer/name as Composer "
+        + "from EHR e contains COMPOSITION c "
+        + "order by c/context/start_time ASCENDING "
+        + "LIMIT 10 OFFSET 10";
+    testAql(aql1, aql1);
+
+    var aql2 = "Select "
+        + "c/name/value as Name, c/context/start_time as date_time, c/composer/name as Composer "
+        + "from EHR e contains COMPOSITION c "
+        + "LIMIT 10 OFFSET 10 "
+        + "order by c/context/start_time ASCENDING";
+    testAql(aql2, aql1);
+
+    var aql3 = "Select "
+        + "c/name/value as Name, c/context/start_time as date_time, c/composer/name as Composer "
+        + "from EHR e contains COMPOSITION c "
+        + "LIMIT 10 OFFSET 10";
+    testAql(aql3, aql3);
+
+    var aql4 = "Select "
+        + "c/name/value as Name, c/context/start_time as date_time, c/composer/name as Composer "
+        + "from EHR e contains COMPOSITION c "
+        + "order by c/context/start_time ASCENDING";
+    testAql(aql4, aql4);
+  }
 }