function order by support (#1108)

Author: tvar

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

@@ -54,6 +54,11 @@ public void visit(Function function) {
         if (function.getKeep() != null) {
             function.getKeep().accept(this);
         }
+        if (function.getOrderByElements() != null) {
+            for (OrderByElement orderByElement : function.getOrderByElements()) {
+                orderByElement.getExpression().accept(this);
+            }
+        }
     }
 
     @Override

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

@@ -14,6 +14,8 @@
 import net.sf.jsqlparser.expression.operators.relational.ExpressionList;
 import net.sf.jsqlparser.expression.operators.relational.NamedExpressionList;
 import net.sf.jsqlparser.parser.ASTNodeAccessImpl;
+import net.sf.jsqlparser.statement.select.OrderByElement;
+import net.sf.jsqlparser.statement.select.PlainSelect;
 
 /**
  * A function as MAX,COUNT...
@@ -28,6 +30,7 @@ public class Function extends ASTNodeAccessImpl implements Expression {
     private boolean isEscaped = false;
     private Expression attribute;
     private String attributeName;
+    private List<OrderByElement> orderByElements;
     private KeepExpression keep = null;
     private boolean ignoreNulls = false;
 
@@ -157,12 +160,29 @@ public String toString() {
 
         if (parameters != null || namedParameters != null) {
             if (parameters != null) {
-                params = parameters.toString();
+                StringBuilder b = new StringBuilder();
+                b.append("(");
                 if (isDistinct()) {
-                    params = params.replaceFirst("\\(", "(DISTINCT ");
-                } else if (isAllColumns()) {
-                    params = params.replaceFirst("\\(", "(ALL ");
+                    b.append("DISTINCT ");
                 }
+                if (isAllColumns()) {
+                    b.append("ALL ");
+                }
+                b.append(PlainSelect.getStringList(parameters.getExpressions(), true, false));
+                if (orderByElements != null) {
+                    b.append(" ORDER BY ");
+                    boolean comma = false;
+                    for (OrderByElement orderByElement : orderByElements) {
+                        if (comma) {
+                            b.append(", ");
+                        } else {
+                            comma = true;
+                        }
+                        b.append(orderByElement);
+                    }
+                }
+                b.append(")");
+                params = b.toString();
             } else {
                 params = namedParameters.toString();
             }
@@ -172,7 +192,7 @@ public String toString() {
             params = "()";
         }
 
-        String ans = getName() + "" + params + "";
+        String ans = getName() + params;
 
         if (attribute != null) {
             ans += "." + attribute.toString();
@@ -231,6 +251,14 @@ public Function withDistinct(boolean distinct) {
         return this;
     }
 
+    public List<OrderByElement> getOrderByElements() {
+        return orderByElements;
+    }
+
+    public void setOrderByElements(List<OrderByElement> orderByElements) {
+        this.orderByElements = orderByElements;
+    }
+
     public <E extends Expression> E getAttribute(Class<E> type) {
         return type.cast(getAttribute());
     }

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

@@ -481,24 +481,42 @@ public void visit(Function function) {
             buffer.append("()");
         } else {
             boolean oldUseBracketsInExprList = useBracketsInExprList;
-            useBracketsInExprList = true;
+            useBracketsInExprList = !function.isDistinct() &&
+                    !function.isAllColumns() &&
+                    function.getOrderByElements() == null;
+            if (!useBracketsInExprList) {
+                buffer.append("(");
+            }
             if (function.isDistinct()) {
-                useBracketsInExprList = false;
-                buffer.append("(DISTINCT ");
+                buffer.append("DISTINCT ");
             } else if (function.isAllColumns()) {
-                useBracketsInExprList = false;
-                buffer.append("(ALL ");
+                buffer.append("ALL ");
             }
             if (function.getNamedParameters() != null) {
                 visit(function.getNamedParameters());
             }
             if (function.getParameters() != null) {
                 visit(function.getParameters());
             }
-            useBracketsInExprList = oldUseBracketsInExprList;
-            if (function.isDistinct() || function.isAllColumns()) {
+            if (function.getOrderByElements() != null) {
+                buffer.append(" ORDER BY ");
+                boolean comma = false;
+                orderByDeParser.setExpressionVisitor(this);
+                orderByDeParser.setBuffer(buffer);
+                for (OrderByElement orderByElement : function.getOrderByElements()) {
+                    if (comma) {
+                        buffer.append(", ");
+                    } else {
+                        comma = true;
+                    }
+                    orderByDeParser.deParseElement(orderByElement);
+                }
+            }
+            if (!useBracketsInExprList) {
                 buffer.append(")");
             }
+            useBracketsInExprList = oldUseBracketsInExprList;
+
         }
 
         if (function.getAttribute() != null) {

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

@@ -311,6 +311,7 @@ public void visit(Function function) {
         validateOptionalItemsList(function.getParameters());
         validateOptionalExpression(function.getAttribute(), this);
         validateOptionalExpression(function.getKeep(), this);
+        validateOptionalOrderByElements(function.getOrderByElements());
     }
 
     @Override

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

@@ -3868,6 +3868,7 @@ Function InternalFunction(Function retval) :
     Token tk1 = null;
     Token tk2 = null;
     Expression expr1 = null;
+    List<OrderByElement> orderByList;
     boolean ignoreNulls = false;
 }
 {
@@ -3881,9 +3882,10 @@ Function InternalFunction(Function retval) :
             |
             LOOKAHEAD(NamedExpressionListExprFirst()) namedExpressionList = NamedExpressionListExprFirst()
             |
-            LOOKAHEAD(3) expressionList=SimpleExpressionList()
+            LOOKAHEAD(3) (expressionList=SimpleExpressionList() [ orderByList = OrderByElements() { retval.setOrderByElements(orderByList); } ])
             |
             expr = SubSelect() { expr.setUseBrackets(false); expressionList = new ExpressionList(expr); }
+
         )]
         [ <K_IGNORE> <K_NULLS> {retval.setIgnoreNulls(true); }]
 	")"

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

@@ -4495,4 +4495,9 @@ public void testKeywordAlgorithmIssue1137() throws JSQLParserException {
     public void testKeywordAlgorithmIssue1138() throws JSQLParserException {
         assertSqlCanBeParsedAndDeparsed("SELECT * FROM in.tablename");
     }
+
+    @Test
+    public void testFunctionOrderBy() throws JSQLParserException {
+        assertSqlCanBeParsedAndDeparsed("SELECT array_agg(DISTINCT s ORDER BY b)[1] FROM t");
+    }
 }