fixed #162

Author: wumpz

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

@@ -22,12 +22,13 @@
 package net.sf.jsqlparser.expression;
 
 /**
- *
+ * Simple uservariables like @test.
  * @author aud
  */
 public class UserVariable implements Expression {
 
 	private String name;
+    private boolean doubleAdd = false;
 
 	/**
 	 * The name of the parameter
@@ -47,8 +48,18 @@ public void accept(ExpressionVisitor expressionVisitor) {
 		expressionVisitor.visit(this);
 	}
 
+    public boolean isDoubleAdd() {
+        return doubleAdd;
+    }
+
+    public void setDoubleAdd(boolean doubleAdd) {
+        this.doubleAdd = doubleAdd;
+    }
+    
+    
+
 	@Override
 	public String toString() {
-		return "@" + name;
+		return "@" + (doubleAdd?"@":"") + name;
 	}
 }

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

@@ -1919,7 +1919,8 @@ UserVariable UserVariable() : {
 	Token token;
 }
 {
-    "@" token=<S_IDENTIFIER> 
+    ("@" | "@@" { var.setDoubleAdd(true);} )
+    token=<S_IDENTIFIER> 
     { 
         var.setName(token.image); 
         return var; 

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

@@ -1921,4 +1921,8 @@ public void testIssue160_signedParameter() throws JSQLParserException {
     public void testIssue160_signedParameter2() throws JSQLParserException {
         assertSqlCanBeParsedAndDeparsed("SELECT * FROM mytable WHERE -? = 5");
     }
+    
+    public void testIssue162_doubleUserVar() throws JSQLParserException {
+        assertSqlCanBeParsedAndDeparsed("SELECT @@SPID AS ID, SYSTEM_USER AS \"Login Name\", USER AS \"User Name\"");
+    }
 }