feat: Piped SQL and FROM queries (WIP)

- `FROM Query` extending `SELECT`
- `WHERE` operator
- `AGGREGATE` operator
- `ORDER BY` operator

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

Author: manticore-projects

README.md

@@ -2,7 +2,7 @@
 
 [![Maven deploy snapshot](https://github.com/JSQLParser/JSqlParser/actions/workflows/maven_deploy.yml/badge.svg)](https://github.com/JSQLParser/JSqlParser/actions/workflows/maven_deploy.yml)
 [![Gradle CI](https://github.com/JSQLParser/JSqlParser/actions/workflows/gradle.yml/badge.svg)](https://github.com/JSQLParser/JSqlParser/actions/workflows/gradle.yml)
-[![Coverage Status](https://coveralls.io/repos/JSQLParser/JSqlParser/badge.svg?branch=master)](https://coveralls.io/r/JSQLParser/JSqlParser?branch=master) 
+[![Coverage Status](https://coveralls.io/repos/JSQLParser/JSqlParser/badge.svg?branch=master)](https://coveralls.io/r/JSQLParser/JSqlParser?branch=master)
 [![Codacy Badge](https://app.codacy.com/project/badge/Grade/6f9a2d7eb98f45969749e101322634a1)](https://www.codacy.com/gh/JSQLParser/JSqlParser/dashboard?utm_source=github.com&utm_medium=referral&utm_content=JSQLParser/JSqlParser&utm_campaign=Badge_Grade)
 [![Maven Central](https://maven-badges.herokuapp.com/maven-central/com.github.jsqlparser/jsqlparser/badge.svg)](http://maven-badges.herokuapp.com/maven-central/com.github.jsqlparser/jsqlparser) [![Javadocs](https://www.javadoc.io/badge/com.github.jsqlparser/jsqlparser.svg)](https://www.javadoc.io/doc/com.github.jsqlparser/jsqlparser)
 [![Gitter](https://badges.gitter.im/JSQLParser/JSqlParser.svg)](https://gitter.im/JSQLParser/JSqlParser?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge)
@@ -47,6 +47,22 @@ Assertions.assertEquals("a", a.getColumnName());
 Assertions.assertEquals("b", b.getColumnName());
 }
 ```
+## Support for `Piped SQL`
+
+Work is progressing for parsing `Piped SQL`, a much saner and more logical way to write queries in its semantic order.
+```sql
+FROM Produce
+|> WHERE
+    item != 'bananas'
+    AND category IN ('fruit', 'nut')
+|> AGGREGATE COUNT(*) AS num_items, SUM(sales) AS total_sales
+   GROUP BY item
+|> ORDER BY item DESC;
+```
+
+For details, please see https://storage.googleapis.com/gweb-research2023-media/pubtools/1004848.pdf,  https://cloud.google.com/bigquery/docs/reference/standard-sql/pipe-syntax and https://duckdb.org/docs/sql/query_syntax/from.html#from-first-syntax
+
+## Java Version
 
 JSQLParser-4.9 was the last JDK8 compatible version. The recent JSQLParser-5.0 depends on JDK11 and introduces API breaking changes to the AST Visitors. Please see the Migration Guide for the details.
 

src/main/java/module-info.java

@@ -38,6 +38,7 @@
     exports net.sf.jsqlparser.statement.grant;
     exports net.sf.jsqlparser.statement.insert;
     exports net.sf.jsqlparser.statement.merge;
+    exports net.sf.jsqlparser.statement.piped;
     exports net.sf.jsqlparser.statement.refresh;
     exports net.sf.jsqlparser.statement.select;
     exports net.sf.jsqlparser.statement.show;

src/main/java/net/sf/jsqlparser/expression/Expression.java

@@ -20,7 +20,4 @@ default <T> void accept(ExpressionVisitor<T> expressionVisitor) {
         this.accept(expressionVisitor, null);
     }
 
-    ;
-
-
 }

src/main/java/net/sf/jsqlparser/expression/ExpressionVisitor.java

@@ -56,6 +56,7 @@
 import net.sf.jsqlparser.expression.operators.relational.TSQLLeftJoin;
 import net.sf.jsqlparser.expression.operators.relational.TSQLRightJoin;
 import net.sf.jsqlparser.schema.Column;
+import net.sf.jsqlparser.statement.piped.FromQuery;
 import net.sf.jsqlparser.statement.select.AllColumns;
 import net.sf.jsqlparser.statement.select.AllTableColumns;
 import net.sf.jsqlparser.statement.select.ParenthesedSelect;
@@ -680,4 +681,6 @@ default void visit(Inverse inverse) {
     }
 
     <S> T visit(CosineSimilarity cosineSimilarity, S context);
+
+    <S> T visit(FromQuery fromQuery, S context);
 }

src/main/java/net/sf/jsqlparser/expression/ExpressionVisitorAdapter.java

@@ -56,6 +56,7 @@
 import net.sf.jsqlparser.expression.operators.relational.TSQLLeftJoin;
 import net.sf.jsqlparser.expression.operators.relational.TSQLRightJoin;
 import net.sf.jsqlparser.schema.Column;
+import net.sf.jsqlparser.statement.piped.FromQuery;
 import net.sf.jsqlparser.statement.select.AllColumns;
 import net.sf.jsqlparser.statement.select.AllTableColumns;
 import net.sf.jsqlparser.statement.select.OrderByElement;
@@ -813,4 +814,9 @@ public <S> T visit(CosineSimilarity cosineSimilarity, S context) {
         return null;
     }
 
+    @Override
+    public <S> T visit(FromQuery fromQuery, S context) {
+        return null;
+    }
+
 }

src/main/java/net/sf/jsqlparser/parser/ASTNodeAccessImpl.java

@@ -65,4 +65,9 @@ public <T extends ASTNodeAccess> T getParent(Class<T> clazz) {
 
         return clazz.cast(parent.jjtGetValue());
     }
+
+    @Override
+    public String toString() {
+        return appendTo(new StringBuilder()).toString();
+    }
 }

src/main/java/net/sf/jsqlparser/statement/StatementVisitor.java

@@ -323,5 +323,4 @@ default void visit(ParenthesedUpdate parenthesedUpdate) {
     default void visit(ParenthesedDelete parenthesedDelete) {
         this.visit(parenthesedDelete, null);
     }
-
 }

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

@@ -0,0 +1,80 @@
+package net.sf.jsqlparser.statement.piped;
+
+import net.sf.jsqlparser.statement.select.SelectItem;
+
+import java.util.ArrayList;
+
+public class AggregatePipeOperator extends PipeOperator {
+    private final ArrayList<SelectItem<?>> selectItems = new ArrayList<>();
+    private final ArrayList<SelectItem<?>> groupItems = new ArrayList<>();
+    private boolean usingShortHandOrdering = false;
+
+    public AggregatePipeOperator(SelectItem<?> selectItem) {
+        selectItems.add(selectItem);
+    }
+
+    public ArrayList<SelectItem<?>> getSelectItems() {
+        return selectItems;
+    }
+
+    public ArrayList<SelectItem<?>> getGroupItems() {
+        return groupItems;
+    }
+
+    public AggregatePipeOperator add(SelectItem<?> selectItem) {
+        selectItems.add(selectItem);
+        return this;
+    }
+
+    public AggregatePipeOperator with(SelectItem<?> selectItem) {
+        return this.add(selectItem);
+    }
+
+    public AggregatePipeOperator addGroupItem(SelectItem<?> selectItem) {
+        groupItems.add(selectItem);
+        return this;
+    }
+
+    public AggregatePipeOperator withGroupItem(SelectItem<?> selectItem) {
+        return this.addGroupItem(selectItem);
+    }
+
+    public boolean isUsingShortHandOrdering() {
+        return usingShortHandOrdering;
+    }
+
+    public AggregatePipeOperator setShorthandOrdering(boolean usingShortHandOrdering) {
+        this.usingShortHandOrdering = usingShortHandOrdering;
+        return this;
+    }
+
+    @Override
+    public <T, S> T accept(PipeOperatorVisitor<T> visitor, S context) {
+        return visitor.visit(this, context);
+    }
+
+    @Override
+    public StringBuilder appendTo(StringBuilder builder) {
+        builder.append("|> ").append("AGGREGATE");
+        int i = 0;
+        for (SelectItem<?> selectItem : selectItems) {
+            builder.append(i++ > 0 ? ", " : " ").append(selectItem);
+        }
+        builder.append("\n");
+
+        if (!groupItems.isEmpty()) {
+            builder.append("\t").append("GROUP");
+            if (isUsingShortHandOrdering()) {
+                builder.append(" AND ORDER");
+            }
+            builder.append(" BY");
+            i = 0;
+            for (SelectItem<?> selectItem : groupItems) {
+                builder.append(i++ > 0 ? ", " : " ").append(selectItem);
+            }
+            builder.append("\n");
+        }
+
+        return builder;
+    }
+}

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

@@ -0,0 +1,9 @@
+package net.sf.jsqlparser.statement.piped;
+
+public class AsPipeOperator extends PipeOperator {
+
+    @Override
+    public <T, S> T accept(PipeOperatorVisitor<T> visitor, S context) {
+        return visitor.visit(this, context);
+    }
+}

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

@@ -0,0 +1,9 @@
+package net.sf.jsqlparser.statement.piped;
+
+public class CallPipeOperator extends PipeOperator {
+
+    @Override
+    public <T, S> T accept(PipeOperatorVisitor<T> visitor, S context) {
+        return visitor.visit(this, context);
+    }
+}