Implement GROUP BY () without columns

JSQLParser · May 28, 2021 · 0c2e522 · 0c2e522
1 parent f83ed0a
commit 0c2e522
Show file tree

Hide file tree

Showing 4 changed files with 53 additions and 4 deletions.
diff --git a/src/main/java/net/sf/jsqlparser/statement/select/GroupByElement.java b/src/main/java/net/sf/jsqlparser/statement/select/GroupByElement.java
@@ -21,6 +21,20 @@ public class GroupByElement {
 
     private List<Expression> groupByExpressions = new ArrayList<>();
     private List groupingSets = new ArrayList();
+    private boolean usingBrackets = false;
+
+    public boolean isUsingBrackets() {
+        return usingBrackets;
+    }
+
+    public void setUsingBrackets(boolean usingBrackets) {
+        this.usingBrackets = usingBrackets;
+    }
+
+    public GroupByElement withUsingBrackets(boolean usingBrackets) {
+        this.usingBrackets = usingBrackets;
+        return this;
+    }
 
     public void accept(GroupByVisitor groupByVisitor) {
         groupByVisitor.visit(this);
@@ -55,12 +69,19 @@ public void addGroupingSet(ExpressionList list) {
     }
 
     @Override
+    @SuppressWarnings({"PMD.CyclomaticComplexity"})
     public String toString() {
         StringBuilder b = new StringBuilder();
         b.append("GROUP BY ");
 
         if (groupByExpressions.size() > 0) {
+            if (usingBrackets) {
+                b.append("( ");
+            }
             b.append(PlainSelect.getStringList(groupByExpressions));
+            if (usingBrackets) {
+                b.append(" )");
+            }
         } else if (groupingSets.size() > 0) {
             b.append("GROUPING SETS (");
             boolean first = true;
@@ -78,6 +99,10 @@ public String toString() {
                 }
             }
             b.append(")");
+        } else {
+            if (usingBrackets) {
+                b.append("()");
+            }
         }
 
         return b.toString();
@@ -94,13 +119,15 @@ public GroupByElement withGroupingSets(List groupingSets) {
     }
 
     public GroupByElement addGroupByExpressions(Expression... groupByExpressions) {
-        List<Expression> collection = Optional.ofNullable(getGroupByExpressions()).orElseGet(ArrayList::new);
+        List<Expression> collection
+                = Optional.ofNullable(getGroupByExpressions()).orElseGet(ArrayList::new);
         Collections.addAll(collection, groupByExpressions);
         return this.withGroupByExpressions(collection);
     }
 
     public GroupByElement addGroupByExpressions(Collection<? extends Expression> groupByExpressions) {
-        List<Expression> collection = Optional.ofNullable(getGroupByExpressions()).orElseGet(ArrayList::new);
+        List<Expression> collection
+                = Optional.ofNullable(getGroupByExpressions()).orElseGet(ArrayList::new);
         collection.addAll(groupByExpressions);
         return this.withGroupByExpressions(collection);
     }

diff --git a/src/main/java/net/sf/jsqlparser/util/deparser/GroupByDeParser.java b/src/main/java/net/sf/jsqlparser/util/deparser/GroupByDeParser.java
@@ -31,14 +31,21 @@ public GroupByDeParser(ExpressionVisitor expressionVisitor, StringBuilder buffer
     }
 
     @Override
+    @SuppressWarnings({"PMD.CyclomaticComplexity", "PMD.NPathComplexity"})
     public void deParse(GroupByElement groupBy) {
         buffer.append("GROUP BY ");
+        if (groupBy.isUsingBrackets()) {
+            buffer.append("( ");
+        }
         for (Iterator<Expression> iter = groupBy.getGroupByExpressions().iterator(); iter.hasNext();) {
             iter.next().accept(expressionVisitor);
             if (iter.hasNext()) {
                 buffer.append(", ");
             }
         }
+        if (groupBy.isUsingBrackets()) {
+            buffer.append(" )");
+        }
         if (!groupBy.getGroupingSets().isEmpty()) {
             buffer.append("GROUPING SETS (");
             boolean first = true;

diff --git a/src/main/jjtree/net/sf/jsqlparser/parser/JSqlParserCC.jjt b/src/main/jjtree/net/sf/jsqlparser/parser/JSqlParserCC.jjt
@@ -2326,9 +2326,15 @@ GroupByElement GroupByColumnReferences():
 }
 {
     <K_GROUP> <K_BY>
-    (
-        columnReference=SimpleExpression() {groupBy.addGroupByExpression(columnReference); }
+    (     LOOKAHEAD(3) (
+              ("(") ( columnReference=SimpleExpression() {groupBy.addGroupByExpression(columnReference); }
         ("," columnReference=SimpleExpression()  {groupBy.addGroupByExpression(columnReference); } )*
+                      )*  (")") { groupBy.setUsingBrackets(true); }
+          )
+          |
+          ( columnReference=SimpleExpression() {groupBy.addGroupByExpression(columnReference); }
+            ("," columnReference=SimpleExpression()  {groupBy.addGroupByExpression(columnReference); } )*
+          )
     |
         <K_GROUPING> <K_SETS> "("
             ( LOOKAHEAD(2) "(" ")" { groupBy.addGroupingSet(new ExpressionList()); }

diff --git a/src/test/java/net/sf/jsqlparser/statement/select/SelectTest.java b/src/test/java/net/sf/jsqlparser/statement/select/SelectTest.java
@@ -4571,4 +4571,13 @@ public void testWithValueListWithOutExtraBrackets1135() throws JSQLParserExcepti
     public void testKeywordSynonymIssue1211() throws JSQLParserException {
         assertSqlCanBeParsedAndDeparsed("select businessDate as \"bd\", synonym as \"synonym\" from sc.tab", true);
     }
+
+    @Test
+    public void testGroupedByIssue1176() throws JSQLParserException {
+        assertSqlCanBeParsedAndDeparsed(
+                "select id_instrument, count(*)\n" + "from cfe.instrument\n" + "group by (id_instrument)",
+                true);
+        assertSqlCanBeParsedAndDeparsed("select count(*)\n" + "from cfe.instrument\n" + "group by ()",
+                true);
+    }
 }