fixes #1581

README.md

@@ -56,6 +56,8 @@ Any requests for examples or any particular documentation will be most welcome.
 
 ## Extensions in the latest SNAPSHOT version 4.6
 
+* support for named windows in window expressions: `SELECT sum(c) OVER winName FROM mytable WINDOW winName AS (PARTITION BY pcol)`
+
 Additionally, we have fixed many errors and improved the code quality and the test coverage.
 
 ## Extensions of JSqlParser releases

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

@@ -16,17 +16,14 @@
 import net.sf.jsqlparser.statement.select.OrderByElement;
 
 /**
- * Analytic function. The name of the function is variable but the parameters following the special
- * analytic function path. e.g. row_number() over (order by test). Additional there can be an
- * expression for an analytical aggregate like sum(col) or the "all collumns" wildcard like
- * count(*).
+ * Analytic function. The name of the function is variable but the parameters following the special analytic function
+ * path. e.g. row_number() over (order by test). Additional there can be an expression for an analytical aggregate like
+ * sum(col) or the "all collumns" wildcard like count(*).
  *
  * @author tw
  */
 public class AnalyticExpression extends ASTNodeAccessImpl implements Expression {
 
-    private final OrderByClause orderBy = new OrderByClause();
-    private final PartitionByClause partitionBy = new PartitionByClause();
     private String name;
     private Expression expression;
     private Expression offset;
@@ -39,8 +36,9 @@ public class AnalyticExpression extends ASTNodeAccessImpl implements Expression
     private boolean ignoreNulls = false;            //IGNORE NULLS inside function parameters
     private boolean ignoreNullsOutside = false;     //IGNORE NULLS outside function parameters
     private Expression filterExpression = null;
-    private WindowElement windowElement = null;
     private List<OrderByElement> funcOrderBy = null;
+    private String windowName = null;               // refers to an external window definition (paritionBy, orderBy, windowElement)
+    private WindowDefinition windowDef = new WindowDefinition();
 
     public AnalyticExpression() {
     }
@@ -76,11 +74,11 @@ public void accept(ExpressionVisitor expressionVisitor) {
     }
 
     public List<OrderByElement> getOrderByElements() {
-        return orderBy.getOrderByElements();
+        return windowDef.orderBy.getOrderByElements();
     }
 
     public void setOrderByElements(List<OrderByElement> orderByElements) {
-        orderBy.setOrderByElements(orderByElements);
+        windowDef.orderBy.setOrderByElements(orderByElements);
     }
 
     public KeepExpression getKeep() {
@@ -92,19 +90,19 @@ public void setKeep(KeepExpression keep) {
     }
 
     public ExpressionList getPartitionExpressionList() {
-        return partitionBy.getPartitionExpressionList();
+        return windowDef.partitionBy.getPartitionExpressionList();
     }
 
     public void setPartitionExpressionList(ExpressionList partitionExpressionList) {
         setPartitionExpressionList(partitionExpressionList, false);
     }
 
     public void setPartitionExpressionList(ExpressionList partitionExpressionList, boolean brackets) {
-        partitionBy.setPartitionExpressionList(partitionExpressionList, brackets);
+        windowDef.partitionBy.setPartitionExpressionList(partitionExpressionList, brackets);
     }
 
     public boolean isPartitionByBrackets() {
-        return partitionBy.isBrackets();
+        return windowDef.partitionBy.isBrackets();
     }
 
     public String getName() {
@@ -140,11 +138,11 @@ public void setDefaultValue(Expression defaultValue) {
     }
 
     public WindowElement getWindowElement() {
-        return windowElement;
+        return windowDef.windowElement;
     }
 
     public void setWindowElement(WindowElement windowElement) {
-        this.windowElement = windowElement;
+        windowDef.windowElement = windowElement;
     }
 
     public AnalyticType getType() {
@@ -187,6 +185,22 @@ public void setIgnoreNullsOutside(boolean ignoreNullsOutside) {
         this.ignoreNullsOutside = ignoreNullsOutside;
     }
 
+    public String getWindowName() {
+        return windowName;
+    }
+
+    public void setWindowName(String windowName) {
+        this.windowName = windowName;
+    }
+
+    public WindowDefinition getWindowDefinition() {
+        return windowDef;
+    }
+
+    public void setWindowDefinition(WindowDefinition windowDef) {
+        this.windowDef = windowDef;
+    }
+
     @Override
     @SuppressWarnings({"PMD.CyclomaticComplexity", "PMD.NPathComplexity", "PMD.MissingBreakInSwitch"})
     public String toString() {
@@ -210,11 +224,11 @@ public String toString() {
         if (isIgnoreNulls()) {
             b.append(" IGNORE NULLS");
         }
-        if (funcOrderBy!=null) {
+        if (funcOrderBy != null) {
             b.append(" ORDER BY ");
-            b.append( funcOrderBy.stream().map(OrderByElement::toString).collect(joining(", ")));
+            b.append(funcOrderBy.stream().map(OrderByElement::toString).collect(joining(", ")));
         }
-        
+
         b.append(") ");
         if (keep != null) {
             b.append(keep.toString()).append(" ");
@@ -232,7 +246,7 @@ public String toString() {
         if (isIgnoreNullsOutside()) {
             b.append("IGNORE NULLS ");
         }
-        
+
         switch (type) {
             case FILTER_ONLY:
                 return b.toString();
@@ -242,20 +256,14 @@ public String toString() {
             default:
                 b.append("OVER");
         }
-        b.append(" (");
 
-        partitionBy.toStringPartitionBy(b);
-        orderBy.toStringOrderByElements(b);
-
-        if (windowElement != null) {
-            if (orderBy.getOrderByElements() != null) {
-                b.append(' ');
-            }
-            b.append(windowElement);
+        if (windowName != null) {
+            b.append(" ").append(windowName);
+        } else {
+            b.append(" ");
+            b.append(windowDef.toString());
         }
 
-        b.append(")");
-
         return b.toString();
     }
 

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

@@ -0,0 +1,83 @@
+/*-
+ * #%L
+ * JSQLParser library
+ * %%
+ * Copyright (C) 2004 - 2022 JSQLParser
+ * %%
+ * Dual licensed under GNU LGPL 2.1 or Apache License 2.0
+ * #L%
+ */
+package net.sf.jsqlparser.expression;
+
+import java.util.List;
+import net.sf.jsqlparser.expression.operators.relational.ExpressionList;
+import net.sf.jsqlparser.statement.select.OrderByElement;
+
+public class WindowDefinition {
+
+    final OrderByClause orderBy = new OrderByClause();
+    final PartitionByClause partitionBy = new PartitionByClause();
+    WindowElement windowElement = null;
+    private String windowName;
+
+    public WindowElement getWindowElement() {
+        return windowElement;
+    }
+
+    public void setWindowElement(WindowElement windowElement) {
+        this.windowElement = windowElement;
+    }
+
+    public List<OrderByElement> getOrderByElements() {
+        return orderBy.getOrderByElements();
+    }
+
+    public void setOrderByElements(List<OrderByElement> orderByElements) {
+        orderBy.setOrderByElements(orderByElements);
+    }
+
+    public ExpressionList getPartitionExpressionList() {
+        return partitionBy.getPartitionExpressionList();
+    }
+
+    public void setPartitionExpressionList(ExpressionList partitionExpressionList) {
+        setPartitionExpressionList(partitionExpressionList, false);
+    }
+
+    public void setPartitionExpressionList(ExpressionList partitionExpressionList, boolean brackets) {
+        partitionBy.setPartitionExpressionList(partitionExpressionList, brackets);
+    }
+
+    public String getWindowName() {
+        return windowName;
+    }
+
+    public void setWindowName(String windowName) {
+        this.windowName = windowName;
+    }
+
+    public WindowDefinition withWindowName(String windowName) {
+        setWindowName(windowName);
+        return this;
+    }
+
+    @Override
+    public String toString() {
+        StringBuilder b = new StringBuilder();
+        if (windowName != null) {
+            b.append(windowName).append(" AS ");
+        }
+        b.append("(");
+        partitionBy.toStringPartitionBy(b);
+        orderBy.toStringOrderByElements(b);
+
+        if (windowElement != null) {
+            if (orderBy.getOrderByElements() != null) {
+                b.append(' ');
+            }
+            b.append(windowElement);
+        }
+        b.append(")");
+        return b.toString();
+    }
+}

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

@@ -15,9 +15,11 @@
 import java.util.Iterator;
 import java.util.List;
 import java.util.Optional;
+import static java.util.stream.Collectors.joining;
 import net.sf.jsqlparser.expression.Expression;
 import net.sf.jsqlparser.expression.OracleHierarchicalExpression;
 import net.sf.jsqlparser.expression.OracleHint;
+import net.sf.jsqlparser.expression.WindowDefinition;
 import net.sf.jsqlparser.parser.ASTNodeAccessImpl;
 import net.sf.jsqlparser.schema.Table;
 
@@ -55,6 +57,7 @@ public class PlainSelect extends ASTNodeAccessImpl implements SelectBody {
     private boolean noWait = false;
     private boolean emitChanges = false;
     private WithIsolation withIsolation;
+    private List<WindowDefinition> windowDefinitions;
 
     public boolean isUseBrackets() {
         return useBrackets;
@@ -230,8 +233,7 @@ public void setHaving(Expression expression) {
     }
 
     /**
-     * A list of {@link Expression}s of the GROUP BY clause. It is null in case
-     * there is no GROUP BY clause
+     * A list of {@link Expression}s of the GROUP BY clause. It is null in case there is no GROUP BY clause
      *
      * @return a list of {@link Expression}s
      */
@@ -331,7 +333,6 @@ public boolean isEmitChanges() {
         return emitChanges;
     }
 
-
     public WithIsolation getWithIsolation() {
         return withIsolation;
     }
@@ -340,8 +341,16 @@ public void setWithIsolation(WithIsolation withIsolation) {
         this.withIsolation = withIsolation;
     }
 
+    public List<WindowDefinition> getWindowDefinitions() {
+        return windowDefinitions;
+    }
+
+    public void setWindowDefinitions(List<WindowDefinition> windowDefinitions) {
+        this.windowDefinitions = windowDefinitions;
+    }
+
     @Override
-    @SuppressWarnings({"PMD.CyclomaticComplexity" , "PMD.ExcessiveMethodLength", "PMD.NPathComplexity"})
+    @SuppressWarnings({"PMD.CyclomaticComplexity", "PMD.ExcessiveMethodLength", "PMD.NPathComplexity"})
     public String toString() {
         StringBuilder sql = new StringBuilder();
         if (useBrackets) {
@@ -418,8 +427,14 @@ public String toString() {
             if (having != null) {
                 sql.append(" HAVING ").append(having);
             }
+
+            if (windowDefinitions != null) {
+                sql.append(" WINDOW ");
+                sql.append(windowDefinitions.stream().map(WindowDefinition::toString).collect(joining(", ")));
+            }
+
             sql.append(orderByToString(oracleSiblings, orderByElements));
-            if (emitChanges){
+            if (emitChanges) {
                 sql.append(" EMIT CHANGES");
             }
             if (limit != null) {
@@ -471,7 +486,7 @@ public String toString() {
             }
             if (withIsolation != null) {
                 sql.append(withIsolation);
-            }            
+            }
         }
         if (forXmlPath != null) {
             sql.append(" FOR XML PATH(").append(forXmlPath).append(")");
@@ -509,8 +524,8 @@ public static String getFormatedList(List<?> list, String expression, boolean us
     }
 
     /**
-     * List the toString out put of the objects in the List comma separated. If the
-     * List is null or empty an empty string is returned.
+     * List the toString out put of the objects in the List comma separated. If the List is null or empty an empty
+     * string is returned.
      *
      * The same as getStringList(list, true, false)
      *
@@ -523,11 +538,11 @@ public static String getStringList(List<?> list) {
     }
 
     /**
-     * List the toString out put of the objects in the List that can be comma
-     * separated. If the List is null or empty an empty string is returned.
+     * List the toString out put of the objects in the List that can be comma separated. If the List is null or empty an
+     * empty string is returned.
      *
-     * @param list        list of objects with toString methods
-     * @param useComma    true if the list has to be comma separated
+     * @param list list of objects with toString methods
+     * @param useComma true if the list has to be comma separated
      * @param useBrackets true if the list has to be enclosed in brackets
      * @return comma separated list of the elements in the list
      */
@@ -536,11 +551,11 @@ public static String getStringList(List<?> list, boolean useComma, boolean useBr
     }
 
     /**
-     * Append the toString out put of the objects in the List (that can be comma
-     * separated). If the List is null or empty an empty string is returned.
+     * Append the toString out put of the objects in the List (that can be comma separated). If the List is null or
+     * empty an empty string is returned.
      *
-     * @param list        list of objects with toString methods
-     * @param useComma    true if the list has to be comma separated
+     * @param list list of objects with toString methods
+     * @param useComma true if the list has to be comma separated
      * @param useBrackets true if the list has to be enclosed in brackets
      * @return comma separated list of the elements in the list
      */
@@ -554,9 +569,9 @@ public static StringBuilder appendStringListTo(StringBuilder builder, List<?> li
 
             int size = list.size();
             for (int i = 0; i < size; i++) {
-                builder.append(list.get(i)).append( i < size - 1
+                builder.append(list.get(i)).append(i < size - 1
                         ? comma + " "
-                        : "" );
+                        : "");
             }
 
             if (useBrackets) {