fixes #243

Author: wumpz

README.md

@@ -42,6 +42,12 @@ Also I would like to know about needed examples or documentation stuff.
 
 ## Extensions in the latest SNAPSHOT version 0.9.6
 
+* improved **top** expression
+
+```java
+SELECT TOP (? + 1) * FROM MyTable
+```
+
 * allowed negative interval expressions like **INTERVAL -420 MINUTES**.
 * support for **ALTER VIEW** statements
 * improved merge statement

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

@@ -21,31 +21,23 @@
  */
 package net.sf.jsqlparser.statement.select;
 
+import net.sf.jsqlparser.expression.Expression;
+
 /**
  * A top clause in the form [TOP (row_count) or TOP row_count]
  */
 public class Top {
 
-    private long rowCount;
-    private boolean rowCountJdbcParameter = false;
     private boolean hasParenthesis = false;
     private boolean isPercentage = false;
+    private Expression expression;
 
-    public long getRowCount() {
-        return rowCount;
-    }
-
-    // TODO instead of a plain number, an expression should be added, which could be a NumberExpression, a GroupedExpression or a JdbcParameter
-    public void setRowCount(long rowCount) {
-        this.rowCount = rowCount;
-    }
-
-    public boolean isRowCountJdbcParameter() {
-        return rowCountJdbcParameter;
+    public Expression getExpression() {
+        return expression;
     }
 
-    public void setRowCountJdbcParameter(boolean rowCountJdbcParameter) {
-        this.rowCountJdbcParameter = rowCountJdbcParameter;
+    public void setExpression(Expression expression) {
+        this.expression = expression;
     }
 
     public boolean hasParenthesis() {
@@ -72,8 +64,7 @@ public String toString() {
             result += "(";
         }
 
-        result += rowCountJdbcParameter ? "?"
-                : rowCount;
+        result += expression.toString();
 
         if (hasParenthesis) {
             result += ")";

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

@@ -1439,17 +1439,17 @@ Top Top():
 {
 	Top top = new Top();
 	Token token = null;
+    Expression expr = null;
 }
 {
 	<K_TOP>
 	(
-	 	token=<S_LONG>                      { top.setRowCount(Long.parseLong(token.image)); }
+	 	token=<S_LONG>                      { top.setExpression(new LongValue(token.image)); }
 	   |
-	 	"?"                                 { top.setRowCountJdbcParameter(true);}
+	 	"?"                                 { top.setExpression(new JdbcParameter()); }
 	   |
 	   "("
-            ( token=<S_LONG>                { top.setRowCount(Long.parseLong(token.image)); }
-              | "?"                         { top.setRowCountJdbcParameter(true);} )
+            expr=AdditiveExpression()   { top.setExpression(expr); }
             { top.setParenthesis(true);}
        ")"
 	) [ LOOKAHEAD(2) <K_PERCENT>            { top.setPercentage(true); } ] 

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

@@ -398,12 +398,12 @@ public void testTop() throws JSQLParserException {
 
         Select select = (Select) parserManager.parse(new StringReader(statement));
 
-        assertEquals(3, ((PlainSelect) select.getSelectBody()).getTop().getRowCount());
+        assertEquals(3, ((LongValue)((PlainSelect) select.getSelectBody()).getTop().getExpression()).getValue());
         assertStatementCanBeDeparsedAs(select, statement);
 
         statement = "select top 5 foo from bar";
         select = (Select) parserManager.parse(new StringReader(statement));
-        assertEquals(5, ((PlainSelect) select.getSelectBody()).getTop().getRowCount());
+        assertEquals(5, ((LongValue)((PlainSelect) select.getSelectBody()).getTop().getExpression()).getValue());
     }
 
     public void testTopWithParenthesis() throws JSQLParserException {
@@ -415,8 +415,7 @@ public void testTopWithParenthesis() throws JSQLParserException {
         final PlainSelect selectBody = (PlainSelect) select.getSelectBody();
 
         final Top top = selectBody.getTop();
-        assertEquals(5, top.getRowCount());
-        assertFalse(top.isRowCountJdbcParameter());
+        assertEquals("5", top.getExpression().toString());
         assertTrue(top.hasParenthesis());
         assertTrue(top.isPercentage());
 
@@ -2188,4 +2187,12 @@ public void testEscapedBackslashIssue253() throws JSQLParserException {
     public void testKeywordTableIssue261() throws JSQLParserException {
         assertSqlCanBeParsedAndDeparsed("SELECT column_value FROM table(VARCHAR_LIST_TYPE())");
     }
+    
+    public void testTopExpressionIssue243() throws JSQLParserException {
+        assertSqlCanBeParsedAndDeparsed("SELECT TOP (? + 1) * FROM MyTable");
+    }
+    
+    public void testTopExpressionIssue243_2() throws JSQLParserException {
+        assertSqlCanBeParsedAndDeparsed("SELECT TOP (CAST(? AS INT)) * FROM MyTable");
+    }
 }