Fix for issue 16.

Author: shubay

src/main/java/com/google/visualization/datasource/util/SqlDataSourceHelper.java

@@ -334,7 +334,7 @@ private static void buildWhereClauseForIsNullFilter(StrBuilder whereClause,
       QueryFilter queryFilter) {
     ColumnIsNullFilter filter = (ColumnIsNullFilter) queryFilter;
 
-    whereClause.append("(").append(filter.getColumn().getId()).append(" IS NULL)");
+    whereClause.append("(").append(getColumnId(filter.getColumn())).append(" IS NULL)");
   }
 
   /**
@@ -352,11 +352,11 @@ private static void buildWhereCluaseForComparisonFilter(
     // Build the left part and the right part of the clause according to the filter's type.
     if (queryFilter instanceof ColumnColumnFilter) {
       ColumnColumnFilter filter = (ColumnColumnFilter) queryFilter;
-      first.append(filter.getFirstColumn().getId());
-      second.append(filter.getSecondColumn().getId());
+      first.append(getColumnId(filter.getFirstColumn()));
+      second.append(getColumnId(filter.getSecondColumn()));
     } else { // The filter is a ColumnValueFilter
       ColumnValueFilter filter = (ColumnValueFilter) queryFilter;
-      first.append(filter.getColumn().getId());
+      first.append(getColumnId(filter.getColumn()));
       second.append(filter.getValue().toString());
       if ((filter.getValue().getType() == ValueType.TEXT)
           || (filter.getValue().getType() == ValueType.DATE)

src/test/java/com/google/visualization/datasource/util/SqlDataSourceHelperTest.java

@@ -180,8 +180,8 @@ public void testBuildWhereClause() {
     StrBuilder queryStringBuilder = new StrBuilder();
     SqlDataSourceHelper.appendWhereClause(query, queryStringBuilder);
     assertEquals(queryStringBuilder.toString(),
-        "WHERE (((ID=Salary) AND (ID>=1.0)) OR ((Fname LIKE \"Mi%\") "
-        + "AND (Lname LIKE \"%SH%\") AND (Lname LIKE \"%tz\"))) ",
+        "WHERE (((`ID`=`Salary`) AND (`ID`>=1.0)) OR ((`Fname` LIKE \"Mi%\") "
+        + "AND (`Lname` LIKE \"%SH%\") AND (`Lname` LIKE \"%tz\"))) ",
         queryStringBuilder.toString());
 
     // Check empty compound filters.
@@ -208,15 +208,15 @@ public void testBuildWhereClause() {
     query.setFilter(queryCompoundFilter6);
     queryStringBuilder = new StrBuilder();
     SqlDataSourceHelper.appendWhereClause(query, queryStringBuilder);
-    assertEquals(queryStringBuilder.toString(), "WHERE ((ID=Salary)) ",
+    assertEquals(queryStringBuilder.toString(), "WHERE ((`ID`=`Salary`)) ",
         queryStringBuilder.toString());
 
     // Check "is null".
     ColumnIsNullFilter isNullFilter = new ColumnIsNullFilter(new SimpleColumn("ID"));
     query.setFilter(isNullFilter);
     queryStringBuilder = new StrBuilder();
     SqlDataSourceHelper.appendWhereClause(query, queryStringBuilder);
-    assertEquals("WHERE (ID IS NULL) ", queryStringBuilder.toString());
+    assertEquals("WHERE (`ID` IS NULL) ", queryStringBuilder.toString());
 
     // Check negation.
     NegationFilter negationFilter =
@@ -225,7 +225,7 @@ public void testBuildWhereClause() {
     query.setFilter(negationFilter);
     queryStringBuilder = new StrBuilder();
     SqlDataSourceHelper.appendWhereClause(query, queryStringBuilder);
-    assertEquals("WHERE (NOT (ID=Salary)) ", queryStringBuilder.toString());
+    assertEquals("WHERE (NOT (`ID`=`Salary`)) ", queryStringBuilder.toString());
   }
 
   /**