refactored group by expressions into separate class, first step to support grouping sets

Author: wumpz

src/main/java/net/sf/jsqlparser/statement/select/GroupByElement.java

@@ -0,0 +1,45 @@
+/*-
+ * #%L
+ * JSQLParser library
+ * %%
+ * Copyright (C) 2004 - 2019 JSQLParser
+ * %%
+ * Dual licensed under GNU LGPL 2.1 or Apache License 2.0
+ * #L%
+ */
+package net.sf.jsqlparser.statement.select;
+
+import java.util.ArrayList;
+import java.util.List;
+import net.sf.jsqlparser.expression.Expression;
+
+public class GroupByElement {
+
+    private List<Expression> groupByExpressions = new ArrayList<>();
+
+    public void accept(GroupByVisitor groupByVisitor) {
+        groupByVisitor.visit(this);
+    }
+
+    public List<Expression> getGroupByExpressions() {
+        return groupByExpressions;
+    }
+
+    public void setGroupByExpressions(List<Expression> groupByExpressions) {
+        this.groupByExpressions = groupByExpressions;
+    }
+
+    public void addGroupByExpression(Expression groupByExpression) {
+        groupByExpressions.add(groupByExpression);
+    }
+
+    @Override
+    public String toString() {
+        StringBuilder b = new StringBuilder();
+        b.append("GROUP BY ");
+
+        b.append(PlainSelect.getStringList(groupByExpressions));
+
+        return b.toString();
+    }
+}

src/main/java/net/sf/jsqlparser/statement/select/GroupByVisitor.java

@@ -0,0 +1,15 @@
+/*-
+ * #%L
+ * JSQLParser library
+ * %%
+ * Copyright (C) 2004 - 2019 JSQLParser
+ * %%
+ * Dual licensed under GNU LGPL 2.1 or Apache License 2.0
+ * #L%
+ */
+package net.sf.jsqlparser.statement.select;
+
+public interface GroupByVisitor {
+
+    void visit(GroupByElement groupBy);
+}

src/main/java/net/sf/jsqlparser/statement/select/PlainSelect.java

@@ -27,7 +27,7 @@ public class PlainSelect extends ASTNodeAccessImpl implements SelectBody {
     private FromItem fromItem;
     private List<Join> joins;
     private Expression where;
-    private List<Expression> groupByColumnReferences;
+    private GroupByElement groupBy;
     private List<OrderByElement> orderByElements;
     private Expression having;
     private Limit limit;
@@ -199,19 +199,19 @@ public void setHaving(Expression expression) {
      *
      * @return a list of {@link Expression}s
      */
-    public List<Expression> getGroupByColumnReferences() {
-        return groupByColumnReferences;
+    public GroupByElement getGroupBy() {
+        return this.groupBy;
     }
 
-    public void setGroupByColumnReferences(List<Expression> list) {
-        groupByColumnReferences = list;
+    public void setGroupByElement(GroupByElement groupBy) {
+        this.groupBy = groupBy;
     }
 
     public void addGroupByColumnReference(Expression expr) {
-        if (groupByColumnReferences == null) {
-            groupByColumnReferences = new ArrayList<Expression>();
+        if (groupBy == null) {
+            groupBy = new GroupByElement();
         }
-        groupByColumnReferences.add(expr);
+        groupBy.addGroupByExpression(expr);
     }
 
     public OracleHierarchicalExpression getOracleHierarchical() {
@@ -343,7 +343,9 @@ public String toString() {
             if (oracleHierarchical != null) {
                 sql.append(oracleHierarchical.toString());
             }
-            sql.append(getFormatedList(groupByColumnReferences, "GROUP BY"));
+            if (groupBy != null) {
+                sql.append(" ").append(groupBy.toString());
+            }
             if (having != null) {
                 sql.append(" HAVING ").append(having);
             }

src/main/java/net/sf/jsqlparser/util/deparser/GroupByDeParser.java

@@ -0,0 +1,47 @@
+/*-
+ * #%L
+ * JSQLParser library
+ * %%
+ * Copyright (C) 2004 - 2019 JSQLParser
+ * %%
+ * Dual licensed under GNU LGPL 2.1 or Apache License 2.0
+ * #L%
+ */
+package net.sf.jsqlparser.util.deparser;
+
+import java.util.Iterator;
+import net.sf.jsqlparser.expression.Expression;
+import net.sf.jsqlparser.expression.ExpressionVisitor;
+import net.sf.jsqlparser.statement.select.GroupByElement;
+
+public class GroupByDeParser {
+
+    protected StringBuilder buffer;
+    private ExpressionVisitor expressionVisitor;
+
+    GroupByDeParser() {
+    }
+
+    public GroupByDeParser(ExpressionVisitor expressionVisitor, StringBuilder buffer) {
+        this.expressionVisitor = expressionVisitor;
+        this.buffer = buffer;
+    }
+
+    public void deParse(GroupByElement groupBy) {
+        buffer.append("GROUP BY ");
+        for (Iterator<Expression> iter = groupBy.getGroupByExpressions().iterator(); iter.hasNext();) {
+            iter.next().accept(expressionVisitor);
+            if (iter.hasNext()) {
+                buffer.append(", ");
+            }
+        }
+    }
+
+    void setExpressionVisitor(ExpressionVisitor expressionVisitor) {
+        this.expressionVisitor = expressionVisitor;
+    }
+
+    void setBuffer(StringBuilder buffer) {
+        this.buffer = buffer;
+    }
+}

src/main/java/net/sf/jsqlparser/util/deparser/SelectDeParser.java

@@ -123,16 +123,9 @@ public void visit(PlainSelect plainSelect) {
             plainSelect.getOracleHierarchical().accept(expressionVisitor);
         }
 
-        if (plainSelect.getGroupByColumnReferences() != null) {
-            buffer.append(" GROUP BY ");
-            for (Iterator<Expression> iter = plainSelect.getGroupByColumnReferences().iterator(); iter.
-                    hasNext();) {
-                Expression columnReference = iter.next();
-                columnReference.accept(expressionVisitor);
-                if (iter.hasNext()) {
-                    buffer.append(", ");
-                }
-            }
+        if (plainSelect.getGroupBy() != null) {
+            buffer.append(" ");
+            new GroupByDeParser(expressionVisitor, buffer).deParse(plainSelect.getGroupBy());
         }
 
         if (plainSelect.getHaving() != null) {
@@ -168,7 +161,7 @@ public void visit(PlainSelect plainSelect) {
             deparseOptimizeFor(plainSelect.getOptimizeFor());
         }
         if (plainSelect.getForXmlPath() != null) {
-            buffer.append(" FOR XML PATH(" + plainSelect.getForXmlPath() + ")");
+            buffer.append(" FOR XML PATH(").append(plainSelect.getForXmlPath()).append(")");
         }
         if (plainSelect.isUseBrackets()) {
             buffer.append(")");

src/main/jjtree/net/sf/jsqlparser/parser/JSqlParserCC.jjt

@@ -1155,7 +1155,7 @@ PlainSelect PlainSelect() #PlainSelect:
     List<SelectItem> distinctOn = null;
     Expression where = null;
     List<OrderByElement> orderByElements;
-    List<Expression> groupByColumnReferences = null;
+    GroupByElement groupBy = null;
     Expression having = null;
     Limit limit = null;
     Offset offset = null;
@@ -1212,7 +1212,7 @@ PlainSelect PlainSelect() #PlainSelect:
 
     [ where=WhereClause() { plainSelect.setWhere(where); }]
     [ oracleHierarchicalQueryClause=OracleHierarchicalQueryClause() { plainSelect.setOracleHierarchical(oracleHierarchicalQueryClause); } ]
-    [ groupByColumnReferences=GroupByColumnReferences() { plainSelect.setGroupByColumnReferences(groupByColumnReferences); }]
+    [ groupBy=GroupByColumnReferences() { plainSelect.setGroupByElement(groupBy); }]
     [ having=Having() { plainSelect.setHaving(having); }]
     [LOOKAHEAD(<K_ORDER> <K_SIBLINGS> <K_BY>) orderByElements = OrderByElements() { plainSelect.setOracleSiblings(true); plainSelect.setOrderByElements(orderByElements);    }   ]
     [LOOKAHEAD(<K_ORDER> <K_BY>) orderByElements = OrderByElements() { plainSelect.setOrderByElements(orderByElements);    }   ]
@@ -1795,16 +1795,16 @@ OracleHierarchicalExpression OracleHierarchicalQueryClause():
     }
 }
 
-List<Expression> GroupByColumnReferences():
+GroupByElement GroupByColumnReferences():
 {
-    Expression columnReference = null;
-    List<Expression> columnReferences = new ArrayList<Expression>();
+    Expression columnReference;
+    GroupByElement groupBy = new GroupByElement();
 }
 {
-    <K_GROUP> <K_BY> columnReference=SimpleExpression() {columnReferences.add(columnReference); }
-    ("," columnReference=SimpleExpression()  {columnReferences.add(columnReference); } )*
+    <K_GROUP> <K_BY> columnReference=SimpleExpression() {groupBy.addGroupByExpression(columnReference); }
+    ("," columnReference=SimpleExpression()  {groupBy.addGroupByExpression(columnReference); } )*
     {
-        return columnReferences;
+        return groupBy;
     }
 }
 

src/test/java/net/sf/jsqlparser/statement/select/SelectTest.java

@@ -1130,17 +1130,17 @@ public void testGroupBy() throws JSQLParserException {
         String statement = "SELECT * FROM tab1 WHERE a > 34 GROUP BY tab1.b";
         Select select = (Select) parserManager.parse(new StringReader(statement));
         PlainSelect plainSelect = (PlainSelect) select.getSelectBody();
-        assertEquals(1, plainSelect.getGroupByColumnReferences().size());
-        assertEquals("tab1.b", ((Column) plainSelect.getGroupByColumnReferences().get(0)).
+        assertEquals(1, plainSelect.getGroupBy().getGroupByExpressions().size());
+        assertEquals("tab1.b", ((Column) plainSelect.getGroupBy().getGroupByExpressions().get(0)).
                 getFullyQualifiedName());
         assertStatementCanBeDeparsedAs(select, statement);
 
         statement = "SELECT * FROM tab1 WHERE a > 34 GROUP BY 2, 3";
         select = (Select) parserManager.parse(new StringReader(statement));
         plainSelect = (PlainSelect) select.getSelectBody();
-        assertEquals(2, plainSelect.getGroupByColumnReferences().size());
-        assertEquals(2, ((LongValue) plainSelect.getGroupByColumnReferences().get(0)).getValue());
-        assertEquals(3, ((LongValue) plainSelect.getGroupByColumnReferences().get(1)).getValue());
+        assertEquals(2, plainSelect.getGroupBy().getGroupByExpressions().size());
+        assertEquals(2, ((LongValue) plainSelect.getGroupBy().getGroupByExpressions().get(0)).getValue());
+        assertEquals(3, ((LongValue) plainSelect.getGroupBy().getGroupByExpressions().get(1)).getValue());
         assertStatementCanBeDeparsedAs(select, statement);
     }
 
@@ -3591,4 +3591,21 @@ public void visit(PlainSelect plainSelect) {
             });
         }
     }
+
+    @Test
+    public void testGroupingSets1() throws JSQLParserException {
+        assertSqlCanBeParsedAndDeparsed("SELECT COL_1, COL_2, COL_3, COL_4, COL_5, COL_6 FROM TABLE_1 "
+                + "GROUP  BY "
+                + " GROUPING SETS( (COL_1, COL_2, COL_3, COL_4), (COL_5, COL_6))");
+    }
+
+    @Test
+    public void testGroupingSets2() throws JSQLParserException {
+        assertSqlCanBeParsedAndDeparsed("SELECT COL_1 FROM TABLE_1 GROUP  BY GROUPING SETS( COL_1 )");
+    }
+
+    @Test
+    public void testGroupingSets3() throws JSQLParserException {
+        assertSqlCanBeParsedAndDeparsed("SELECT COL_1 FROM TABLE_1 GROUP  BY GROUPING SETS( COL_1, () )");
+    }
 }