Unparenthesized SubSelect as FromItem (#2073)

* feat: Implement FromItem in Select

Implement FromItem interface in Select to allow Select being an unparenthesized FromItem

Refs: #2071

* feat: Implement grammar to support Select as FromItem

Refs: #2071

* style: Run gradle :spotlessApply

* style: Run gradle :spotlessApply

---------

Co-authored-by: Stefan Steinhauser <stefan.steinhauser@arz.at>

Author: ssteinhauser

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

@@ -47,5 +47,26 @@ default FromItem withUnPivot(UnPivot unpivot) {
         return this;
     }
 
+    default StringBuilder appendTo(StringBuilder builder, Alias alias) {
+        return appendTo(builder, alias, null, null);
+    }
+
+    default StringBuilder appendTo(StringBuilder builder, Alias alias, Pivot pivot,
+            UnPivot unPivot) {
+        if (alias != null) {
+            builder.append(alias);
+        }
+
+        if (pivot != null) {
+            builder.append(" ").append(pivot);
+        }
+
+        if (unPivot != null) {
+            builder.append(" ").append(unPivot);
+        }
+
+        return builder;
+    }
+
 
 }

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

@@ -48,4 +48,22 @@ default void visit(ParenthesedFromItem parenthesedFromItem) {
     default void visit(Values values) {
         this.visit(values, null);
     }
+
+    <S> T visit(PlainSelect plainSelect, S context);
+
+    default void visit(PlainSelect plainSelect) {
+        this.visit(plainSelect, null);
+    }
+
+    <S> T visit(SetOperationList setOperationList, S context);
+
+    default void visit(SetOperationList setOperationList) {
+        this.visit(setOperationList, null);
+    }
+
+    <S> T visit(TableStatement tableStatement, S context);
+
+    default void visit(TableStatement tableStatement) {
+        this.visit(tableStatement, null);
+    }
 }

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

@@ -49,4 +49,22 @@ public <S> T visit(Values values, S context) {
 
         return null;
     }
+
+    @Override
+    public <S> T visit(PlainSelect plainSelect, S context) {
+
+        return null;
+    }
+
+    @Override
+    public <S> T visit(SetOperationList setOperationList, S context) {
+
+        return null;
+    }
+
+    @Override
+    public <S> T visit(TableStatement tableStatement, S context) {
+
+        return null;
+    }
 }

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

@@ -160,15 +160,7 @@ public <T, S> T accept(StatementVisitor<T> statementVisitor, S context) {
 
     public StringBuilder appendSelectBodyTo(StringBuilder builder) {
         builder.append("(").append(select).append(")");
-        if (alias != null) {
-            builder.append(alias);
-        }
-        if (pivot != null) {
-            builder.append(" ").append(pivot);
-        }
-        if (unPivot != null) {
-            builder.append(" ").append(unPivot);
-        }
+        appendTo(builder, alias, pivot, unPivot);
         return builder;
     }
 }

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

@@ -317,6 +317,11 @@ public <T, S> T accept(SelectVisitor<T> selectVisitor, S context) {
         return selectVisitor.visit(this, context);
     }
 
+    @Override
+    public <T, S> T accept(FromItemVisitor<T> fromItemVisitor, S context) {
+        return fromItemVisitor.visit(this, context);
+    }
+
     public OptimizeFor getOptimizeFor() {
         return optimizeFor;
     }

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

@@ -9,6 +9,7 @@
  */
 package net.sf.jsqlparser.statement.select;
 
+import net.sf.jsqlparser.expression.Alias;
 import net.sf.jsqlparser.expression.Expression;
 import net.sf.jsqlparser.expression.ExpressionVisitor;
 import net.sf.jsqlparser.parser.ASTNodeAccessImpl;
@@ -23,7 +24,7 @@
 import java.util.List;
 import java.util.Optional;
 
-public abstract class Select extends ASTNodeAccessImpl implements Statement, Expression {
+public abstract class Select extends ASTNodeAccessImpl implements Statement, Expression, FromItem {
     protected Table forUpdateTable = null;
     List<WithItem<?>> withItemsList;
     Limit limitBy;
@@ -40,6 +41,9 @@ public abstract class Select extends ASTNodeAccessImpl implements Statement, Exp
     private boolean skipLocked;
     private Wait wait;
     private boolean noWait = false;
+    Alias alias;
+    Pivot pivot;
+    UnPivot unPivot;
 
     public static String orderByToString(List<OrderByElement> orderByElements) {
         return orderByToString(false, orderByElements);
@@ -322,6 +326,39 @@ public void setSkipLocked(boolean skipLocked) {
         this.skipLocked = skipLocked;
     }
 
+    @Override
+    public Alias getAlias() {
+        return alias;
+    }
+
+    @Override
+    public void setAlias(Alias alias) {
+        this.alias = alias;
+    }
+
+    public Select withAlias(Alias alias) {
+        this.setAlias(alias);
+        return this;
+    }
+
+    @Override
+    public Pivot getPivot() {
+        return pivot;
+    }
+
+    @Override
+    public void setPivot(Pivot pivot) {
+        this.pivot = pivot;
+    }
+
+    public UnPivot getUnPivot() {
+        return unPivot;
+    }
+
+    public void setUnPivot(UnPivot unPivot) {
+        this.unPivot = unPivot;
+    }
+
     public abstract StringBuilder appendSelectBodyTo(StringBuilder builder);
 
     @SuppressWarnings({"PMD.CyclomaticComplexity"})
@@ -381,6 +418,8 @@ public StringBuilder appendTo(StringBuilder builder) {
             }
         }
 
+        appendTo(builder, alias, pivot, unPivot);
+
         return builder;
     }
 

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

@@ -27,6 +27,11 @@ public <T, S> T accept(SelectVisitor<T> selectVisitor, S context) {
         return selectVisitor.visit(this, context);
     }
 
+    @Override
+    public <T, S> T accept(FromItemVisitor<T> fromItemVisitor, S context) {
+        return fromItemVisitor.visit(this, context);
+    }
+
     public List<OrderByElement> getOrderByElements() {
         return orderByElements;
     }

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

@@ -55,4 +55,9 @@ public StringBuilder appendTo(StringBuilder builder) {
     public <T, S> T accept(SelectVisitor<T> selectVisitor, S context) {
         return selectVisitor.visit(this, context);
     }
+
+    @Override
+    public <T, S> T accept(FromItemVisitor<T> fromItemVisitor, S context) {
+        return fromItemVisitor.visit(this, context);
+    }
 }

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

@@ -48,9 +48,7 @@ public void setExpressions(ExpressionList<Expression> expressions) {
     public StringBuilder appendSelectBodyTo(StringBuilder builder) {
         builder.append("VALUES ");
         builder.append(expressions.toString());
-        if (alias != null) {
-            builder.append(" ").append(alias);
-        }
+        appendTo(builder, alias);
         return builder;
     }
 

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

@@ -103,7 +103,7 @@ public <S> StringBuilder visit(ParenthesedSelect select, S context) {
         }
 
         buffer.append("(");
-        select.getSelect().accept(this, context);
+        select.getSelect().accept((SelectVisitor<StringBuilder>) this, context);
         buffer.append(")");
 
         if (select.getOrderByElements() != null) {
@@ -330,6 +330,20 @@ public <S> StringBuilder visit(PlainSelect plainSelect, S context) {
         if (plainSelect.isUseWithNoLog()) {
             buffer.append(" WITH NO LOG");
         }
+
+        Alias alias = plainSelect.getAlias();
+        if (alias != null) {
+            buffer.append(alias);
+        }
+        Pivot pivot = plainSelect.getPivot();
+        if (pivot != null) {
+            pivot.accept(this, context);
+        }
+        UnPivot unpivot = plainSelect.getUnPivot();
+        if (unpivot != null) {
+            unpivot.accept(this, context);
+        }
+
         return buffer;
     }
 
@@ -618,7 +632,7 @@ public <S> StringBuilder visit(SetOperationList list, S context) {
             if (i != 0) {
                 buffer.append(' ').append(list.getOperations().get(i - 1)).append(' ');
             }
-            list.getSelects().get(i).accept(this, context);
+            list.getSelects().get(i).accept((SelectVisitor<StringBuilder>) this, context);
         }
         if (list.getOrderByElements() != null) {
             new OrderByDeParser(expressionVisitor, buffer).deParse(list.getOrderByElements());
@@ -636,6 +650,20 @@ public <S> StringBuilder visit(SetOperationList list, S context) {
         if (list.getIsolation() != null) {
             buffer.append(list.getIsolation().toString());
         }
+
+        Alias alias = list.getAlias();
+        if (alias != null) {
+            buffer.append(alias);
+        }
+        Pivot pivot = list.getPivot();
+        if (pivot != null) {
+            pivot.accept(this, context);
+        }
+        UnPivot unpivot = list.getUnPivot();
+        if (unpivot != null) {
+            unpivot.accept(this, context);
+        }
+
         return buffer;
     }
 
@@ -779,7 +807,7 @@ private void deparseOptimizeFor(OptimizeFor optimizeFor) {
 
     @Override
     void deParse(PlainSelect statement) {
-        statement.accept(this, null);
+        statement.accept((SelectVisitor<StringBuilder>) this, null);
     }
 
 }

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

@@ -214,7 +214,7 @@ private <S> StringBuilder addWithItemsToBuffer(List<WithItem<?>> withItemsList,
 
     @Override
     public <S> StringBuilder visit(Select select, S context) {
-        select.accept(selectDeParser, context);
+        select.accept((SelectVisitor<StringBuilder>) selectDeParser, context);
         return buffer;
     }
 

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

@@ -10,15 +10,7 @@
 package net.sf.jsqlparser.util.deparser;
 
 import net.sf.jsqlparser.expression.ExpressionVisitor;
-import net.sf.jsqlparser.statement.select.LateralSubSelect;
-import net.sf.jsqlparser.statement.select.Offset;
-import net.sf.jsqlparser.statement.select.ParenthesedSelect;
-import net.sf.jsqlparser.statement.select.PlainSelect;
-import net.sf.jsqlparser.statement.select.SelectVisitor;
-import net.sf.jsqlparser.statement.select.SetOperationList;
-import net.sf.jsqlparser.statement.select.TableStatement;
-import net.sf.jsqlparser.statement.select.Values;
-import net.sf.jsqlparser.statement.select.WithItem;
+import net.sf.jsqlparser.statement.select.*;
 
 /**
  * @author jxnu-liguobin
@@ -101,6 +93,10 @@ public <S> StringBuilder visit(TableStatement tableStatement, S context) {
         }
 
         // TODO UNION
+
+        tableStatement.appendTo(buffer, tableStatement.getAlias(), tableStatement.getPivot(),
+                tableStatement.getUnPivot());
+
         return buffer;
     }
 }

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

@@ -75,7 +75,7 @@ public void deParse(Upsert upsert) {
 
             if (upsert.getSelect() != null) {
                 buffer.append(" ");
-                upsert.getSelect().accept(selectVisitor, null);
+                upsert.getSelect().accept((SelectVisitor<StringBuilder>) selectVisitor, null);
             }
 
             if (upsert.getDuplicateUpdateSets() != null) {

src/main/java/net/sf/jsqlparser/util/validation/validator/AlterViewValidator.java

@@ -11,6 +11,7 @@
 
 import net.sf.jsqlparser.parser.feature.Feature;
 import net.sf.jsqlparser.statement.create.view.AlterView;
+import net.sf.jsqlparser.statement.select.SelectVisitor;
 import net.sf.jsqlparser.util.validation.ValidationCapability;
 import net.sf.jsqlparser.util.validation.metadata.NamedObject;
 
@@ -27,7 +28,8 @@ public void validate(AlterView alterView) {
             validateName(c, NamedObject.view, alterView.getView().getFullyQualifiedName());
             validateOptionalColumnNames(c, alterView.getColumnNames());
         }
-        alterView.getSelect().accept(getValidator(SelectValidator.class), null);
+        alterView.getSelect().accept((SelectVisitor<Void>) getValidator(SelectValidator.class),
+                null);
     }
 
 }

src/main/java/net/sf/jsqlparser/util/validation/validator/CreateViewValidator.java

@@ -14,6 +14,7 @@
 import net.sf.jsqlparser.statement.create.view.ForceOption;
 import net.sf.jsqlparser.statement.create.view.TemporaryOption;
 import net.sf.jsqlparser.statement.select.Select;
+import net.sf.jsqlparser.statement.select.SelectVisitor;
 import net.sf.jsqlparser.util.validation.ValidationCapability;
 import net.sf.jsqlparser.util.validation.metadata.NamedObject;
 
@@ -38,7 +39,7 @@ public void validate(CreateView createView) {
         }
         SelectValidator v = getValidator(SelectValidator.class);
         Select select = createView.getSelect();
-        select.accept(v, null);
+        select.accept((SelectVisitor<Void>) v, null);
     }
 
 }