add wall test

src/main/java/com/alibaba/druid/filter/wall/spi/WallVisitorUtils.java

@@ -209,6 +209,19 @@ public class WallVisitorUtils {
                 return ((String) firstValue).length();
             }
         }
+        
+        if ("if".equalsIgnoreCase(methodName) && x.getParameters().size() == 3) {
+            SQLExpr first = x.getParameters().get(0);
+            Object firstResult = getValue(first);
+            
+            if (Boolean.TRUE == firstResult) {
+                return getValue(x.getParameters().get(1));
+            }
+            
+            if (Boolean.FALSE == firstResult) {
+                getValue(x.getParameters().get(2));
+            }
+        }
 
         return null;
     }
@@ -277,6 +290,8 @@ public class WallVisitorUtils {
 
             if (propExpr.getOwner() instanceof SQLIdentifierExpr) {
                 String ownerName = ((SQLIdentifierExpr) propExpr.getOwner()).getName();
+                
+                ownerName = form(ownerName);
 
                 if (visitor.getPermitSchemas().contains(ownerName.toLowerCase())) {
                     visitor.getViolations().add(new IllegalSQLObjectViolation(visitor.toSQL(x)));
@@ -327,6 +342,9 @@ public class WallVisitorUtils {
         if (name.startsWith("\"") && name.endsWith("\"")) {
             name = name.substring(1, name.length() - 1);
         }
+        if (name.startsWith("`") && name.endsWith("`")) {
+            name = name.substring(1, name.length() - 1);
+        }
         
         name = name.toLowerCase();
         return name;

src/main/java/com/alibaba/druid/sql/parser/SQLExprParser.java

@@ -273,9 +273,9 @@ public class SQLExprParser extends SQLParser {
 
                     accept(Token.RPAREN);
                     notTarget = exprRest(notTarget);
-                    
+
                     sqlExpr = new SQLNotExpr(notTarget);
-                    
+
                     return primaryRest(sqlExpr);
                 } else {
                     SQLExpr restExpr = expr();
@@ -468,6 +468,11 @@ public class SQLExprParser extends SQLParser {
         if (lexer.token() == Token.DOT) {
             lexer.nextToken();
 
+            if (expr instanceof SQLCharExpr) {
+                String text = ((SQLCharExpr) expr).getText();
+                expr = new SQLIdentifierExpr(text);
+            }
+
             expr = dotRest(expr);
             return primaryRest(expr);
         } else if (lexer.token() == Token.COLONEQ) {
@@ -635,7 +640,11 @@ public class SQLExprParser extends SQLParser {
                 throw new ParserException("error, " + lexer.token());
             }
 
-            name = new SQLPropertyExpr(name, lexer.stringVal());
+            if (lexer.token() == Token.LITERAL_ALIAS) {
+                name = new SQLPropertyExpr(name, '"' + lexer.stringVal() + '"');
+            } else {
+                name = new SQLPropertyExpr(name, lexer.stringVal());
+            }
             lexer.nextToken();
         }
 

src/main/java/com/alibaba/druid/sql/parser/SQLSelectParser.java

@@ -227,6 +227,11 @@ public class SQLSelectParser extends SQLParser {
     }
 
     private void parseTableSourceQueryTableExpr(SQLExprTableSource tableReference) throws ParserException {
+        if (lexer.token() == Token.LITERAL_ALIAS || lexer.token() == Token.IDENTIFIED || lexer.token() == Token.LITERAL_CHARS) {
+            tableReference.setExpr(this.createExprParser().name());
+            return;
+        }
+        
         tableReference.setExpr(expr());
     }