feat: SELECT piper operator to support ALL | DISTINCT

- fixes starlake-ai/jsqltranspiler#71

Signed-off-by: Andreas Reichel <andreas@manticore-projects.com>

Author: manticore-projects

src/main/java/net/sf/jsqlparser/statement/piped/ExtendPipeOperator.java

@@ -4,6 +4,6 @@
 
 public class ExtendPipeOperator extends SelectPipeOperator {
     public ExtendPipeOperator(SelectItem<?> selectItem) {
-        super("EXTEND", selectItem);
+        super("EXTEND", selectItem, null);
     }
 }

src/main/java/net/sf/jsqlparser/statement/piped/RenamePipeOperator.java

@@ -4,6 +4,6 @@
 
 public class RenamePipeOperator extends SelectPipeOperator {
     public RenamePipeOperator(SelectItem<?> selectItem) {
-        super("RENAME", selectItem);
+        super("RENAME", selectItem, null);
     }
 }

src/main/java/net/sf/jsqlparser/statement/piped/SelectPipeOperator.java

@@ -6,22 +6,24 @@
 
 public class SelectPipeOperator extends PipeOperator {
     private final String operatorName;
+    private final String modifier;
 
     private final ArrayList<SelectItem<?>> selectItems = new ArrayList<>();
 
-    public SelectPipeOperator(String operatorName, SelectItem<?> selectItem) {
+    public SelectPipeOperator(String operatorName, SelectItem<?> selectItem, String modifier) {
         this.operatorName = operatorName;
+        this.modifier = modifier;
         selectItems.add(selectItem);
     }
 
-    public SelectPipeOperator(SelectItem<?> selectItem) {
-        this("SELECT", selectItem);
-    }
-
     public String getOperatorName() {
         return operatorName;
     }
 
+    public String getModifier() {
+        return modifier;
+    }
+
     public ArrayList<SelectItem<?>> getSelectItems() {
         return selectItems;
     }
@@ -43,6 +45,10 @@ public <T, S> T accept(PipeOperatorVisitor<T, S> visitor, S context) {
     @Override
     public StringBuilder appendTo(StringBuilder builder) {
         builder.append("|> ").append(operatorName);
+        if (modifier != null && !modifier.isEmpty()) {
+            builder.append(" ").append(modifier);
+        }
+
         int i = 0;
         for (SelectItem<?> selectItem : selectItems) {
             builder.append(i++ > 0 ? ", " : " ").append(selectItem);

src/main/java/net/sf/jsqlparser/statement/piped/WindowPipeOperator.java

@@ -4,6 +4,6 @@
 
 public class WindowPipeOperator extends SelectPipeOperator {
     public WindowPipeOperator(SelectItem<?> selectItem) {
-        super("WINDOW", selectItem);
+        super("WINDOW", selectItem, null);
     }
 }

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

@@ -980,6 +980,10 @@ public StringBuilder visit(RenamePipeOperator rename, Void context) {
     @Override
     public StringBuilder visit(SelectPipeOperator select, Void context) {
         builder.append("|> ").append(select.getOperatorName());
+        if (select.getModifier() != null && !select.getModifier().isEmpty()) {
+            builder.append(" ").append(select.getModifier());
+        }
+
         int i = 0;
         for (SelectItem<?> selectItem : select.getSelectItems()) {
             builder.append(i++ > 0 ? ", " : " ").append(selectItem);

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

@@ -2424,12 +2424,13 @@ PipeOperator PipeOperator() #PipeOperator:
 SelectPipeOperator SelectPipeOperator():
 {
     Token operatorKeyToken;
+    Token modifierToken = null;
     SelectPipeOperator selectPipeOperator;
     SelectItem<?> selectItem;
 }
 {
     (
-        operatorKeyToken = <K_SELECT>
+        ( operatorKeyToken = <K_SELECT> [ modifierToken=<K_DISTINCT> | modifierToken=<K_ALL> ] )
         |
         operatorKeyToken = <K_EXTEND>
         |
@@ -2438,7 +2439,7 @@ SelectPipeOperator SelectPipeOperator():
         operatorKeyToken = <K_RENAME>
     )
     selectItem = SelectItem()
-    { selectPipeOperator = new SelectPipeOperator(operatorKeyToken.image, selectItem); }
+    { selectPipeOperator = new SelectPipeOperator(operatorKeyToken.image, selectItem, modifierToken !=null ? modifierToken.image : null); }
 
     ( LOOKAHEAD(2) "," selectItem = SelectItem() { selectPipeOperator.add(selectItem); } )*
 

src/test/java/net/sf/jsqlparser/statement/piped/SelectPipeOperatorTest.java

@@ -14,4 +14,14 @@ void testRename() throws JSQLParserException {
                 + "|> SELECT *, t.y AS t_y;";
         TestUtils.assertSqlCanBeParsedAndDeparsed(sqlStr, true);
     }
+
+    @Test
+    void testDistinct() throws JSQLParserException {
+        String sqlStr = "FROM orders\n" +
+                "|> WHERE order_date >= '2024-01-01'\n" +
+                "|> SELECT DISTINCT customer_id \n" +
+                "|> INNER JOIN customers USING(customer_id)\n" +
+                "|> SELECT *;";
+        TestUtils.assertSqlCanBeParsedAndDeparsed(sqlStr, true);
+    }
 }