diff --git a/src/main/java/com/alibaba/druid/sql/ast/expr/SQLBinaryOpExpr.java b/src/main/java/com/alibaba/druid/sql/ast/expr/SQLBinaryOpExpr.java
index 6c76b18435..c374a2a443 100644
--- a/src/main/java/com/alibaba/druid/sql/ast/expr/SQLBinaryOpExpr.java
+++ b/src/main/java/com/alibaba/druid/sql/ast/expr/SQLBinaryOpExpr.java
@@ -34,8 +34,8 @@ public class SQLBinaryOpExpr extends SQLExprImpl implements Serializable {
 
     public SQLBinaryOpExpr(SQLExpr left, SQLBinaryOperator operator, SQLExpr right){
 
-        this.left = left;
-        this.right = right;
+        setLeft(left);
+        setRight(right);
         this.operator = operator;
     }
 
@@ -51,6 +51,9 @@ public class SQLBinaryOpExpr extends SQLExprImpl implements Serializable {
     }
 
     public void setLeft(SQLExpr left) {
+        if (left != null) {
+            left.setParent(this);
+        }
         this.left = left;
     }
 
@@ -59,6 +62,9 @@ public class SQLBinaryOpExpr extends SQLExprImpl implements Serializable {
     }
 
     public void setRight(SQLExpr right) {
+        if (right != null) {
+            right.setParent(this);
+        }
         this.right = right;
     }
 
diff --git a/src/main/java/com/alibaba/druid/sql/dialect/mysql/parser/MySqlLexer.java b/src/main/java/com/alibaba/druid/sql/dialect/mysql/parser/MySqlLexer.java
index cf76fec9a5..36b6976a21 100644
--- a/src/main/java/com/alibaba/druid/sql/dialect/mysql/parser/MySqlLexer.java
+++ b/src/main/java/com/alibaba/druid/sql/dialect/mysql/parser/MySqlLexer.java
@@ -61,6 +61,51 @@ public class MySqlLexer extends Lexer {
         super(input);
         super.keywods = DEFAULT_MYSQL_KEYWORDS;
     }
+    
+    public void scanSharp() {
+        if (ch != '#') {
+            throw new ParserException("illegal stat");
+        }
+        
+        Token lastToken = this.token;
+        
+        scanChar();
+        mark = pos;
+        bufPos = 0;
+        for (;;) {
+            if (ch == '\r') {
+                if (charAt(pos + 1) == '\n') {
+                    bufPos += 2;
+                    scanChar();
+                    break;
+                }
+                bufPos++;
+                break;
+            } else if (ch == EOI) {
+                break;
+            }
+
+            if (ch == '\n') {
+                scanChar();
+                bufPos++;
+                break;
+            }
+
+            scanChar();
+            bufPos++;
+        }
+        
+        stringVal = subString(mark, bufPos);
+        token = Token.LINE_COMMENT;
+        
+        if (commentHandler != null && commentHandler.handle(lastToken, stringVal)) {
+            return;
+        }
+
+        if (!isAllowComment()) {
+            throw new NotAllowCommentException();
+        }
+    }
 
     public void scanVariable() {
         if (ch != '@' && ch != ':' && ch != '#' && ch != '$') {
diff --git a/src/main/java/com/alibaba/druid/sql/parser/Lexer.java b/src/main/java/com/alibaba/druid/sql/parser/Lexer.java
index 1283bf9528..53707630fb 100644
--- a/src/main/java/com/alibaba/druid/sql/parser/Lexer.java
+++ b/src/main/java/com/alibaba/druid/sql/parser/Lexer.java
@@ -360,7 +360,11 @@ public class Lexer {
                     }
                     return;
                 case '#':
-                    scanVariable();
+                    scanSharp();
+                    if ((token() == Token.LINE_COMMENT || token() == Token.MULTI_LINE_COMMENT) && skipComment) {
+                        bufPos = 0;
+                        continue;
+                    }
                     return;
                 case '.':
                     scanChar();
@@ -648,6 +652,10 @@ public class Lexer {
 
         stringVal = subString(mark + 1, bufPos);
     }
+    
+    public void scanSharp() {
+        scanVariable();
+    }
 
     public void scanVariable() {
         if (ch != '@' && ch != ':' && ch != '#' && ch != '$') {
diff --git a/src/main/java/com/alibaba/druid/sql/visitor/SQLEvalVisitor.java b/src/main/java/com/alibaba/druid/sql/visitor/SQLEvalVisitor.java
index 2efaf59b16..72bd1c3eed 100644
--- a/src/main/java/com/alibaba/druid/sql/visitor/SQLEvalVisitor.java
+++ b/src/main/java/com/alibaba/druid/sql/visitor/SQLEvalVisitor.java
@@ -25,6 +25,7 @@ public interface SQLEvalVisitor extends SQLASTVisitor {
     public static final String EVAL_EXPR        = "eval.expr";
     public static final Object EVAL_ERROR       = new Object();
     public static final Object EVAL_VALUE_COUNT = new Object();
+    public static final Object EVAL_VALUE_NULL = new Object();
 
     Function getFunction(String funcName);
 
diff --git a/src/main/java/com/alibaba/druid/sql/visitor/SQLEvalVisitorUtils.java b/src/main/java/com/alibaba/druid/sql/visitor/SQLEvalVisitorUtils.java
index b94662c124..880e72e2ea 100644
--- a/src/main/java/com/alibaba/druid/sql/visitor/SQLEvalVisitorUtils.java
+++ b/src/main/java/com/alibaba/druid/sql/visitor/SQLEvalVisitorUtils.java
@@ -62,10 +62,14 @@ import com.alibaba.druid.sql.visitor.functions.Char;
 import com.alibaba.druid.sql.visitor.functions.Concat;
 import com.alibaba.druid.sql.visitor.functions.Elt;
 import com.alibaba.druid.sql.visitor.functions.Function;
+import com.alibaba.druid.sql.visitor.functions.Greatest;
 import com.alibaba.druid.sql.visitor.functions.Hex;
+import com.alibaba.druid.sql.visitor.functions.If;
 import com.alibaba.druid.sql.visitor.functions.Insert;
 import com.alibaba.druid.sql.visitor.functions.Instr;
+import com.alibaba.druid.sql.visitor.functions.Isnull;
 import com.alibaba.druid.sql.visitor.functions.Lcase;
+import com.alibaba.druid.sql.visitor.functions.Least;
 import com.alibaba.druid.sql.visitor.functions.Left;
 import com.alibaba.druid.sql.visitor.functions.Length;
 import com.alibaba.druid.sql.visitor.functions.Locate;
@@ -185,6 +189,10 @@ public class SQLEvalVisitorUtils {
         functions.put("lower", Lcase.instance);
         functions.put("hex", Hex.instance);
         functions.put("unhex", Unhex.instance);
+        functions.put("greatest", Greatest.instance);
+        functions.put("least", Least.instance);
+        functions.put("isnull", Isnull.instance);
+        functions.put("if", If.instance);
     }
 
     public static boolean visit(SQLEvalVisitor visitor, SQLMethodInvokeExpr x) {
@@ -518,6 +526,8 @@ public class SQLEvalVisitorUtils {
                 char ch = (char) intValue;
                 x.putAttribute(EVAL_VALUE, Character.toString(ch));
             }
+        } else if ("CURRENT_USER".equals(methodName)) {
+            x.putAttribute(EVAL_VALUE, "CURRENT_USER");
         }
         return false;
     }
@@ -954,7 +964,7 @@ public class SQLEvalVisitorUtils {
         if (val instanceof Short) {
             return (Short) val;
         }
-        
+
         if (val instanceof String) {
             return Short.parseShort((String) val);
         }
@@ -975,7 +985,7 @@ public class SQLEvalVisitorUtils {
         if (val instanceof String) {
             return Integer.parseInt((String) val);
         }
-        
+
         if (val instanceof List) {
             List list = (List) val;
             if (list.size() == 1) {
@@ -983,6 +993,14 @@ public class SQLEvalVisitorUtils {
             }
         }
 
+        if (val instanceof Boolean) {
+            if (((Boolean) val).booleanValue()) {
+                return 1;
+            } else {
+                return 0;
+            }
+        }
+
         return ((Number) val).intValue();
     }
 
@@ -995,12 +1013,11 @@ public class SQLEvalVisitorUtils {
         if (val instanceof Long) {
             return (Long) val;
         }
-        
+
         if (val instanceof String) {
             return Long.parseLong((String) val);
         }
-        
-        
+
         if (val instanceof List) {
             List list = (List) val;
             if (list.size() == 1) {
@@ -1424,7 +1441,7 @@ public class SQLEvalVisitorUtils {
         if (b == null) {
             return a;
         }
-        
+
         if (a instanceof Date || b instanceof Date) {
             return SQLEvalVisitor.EVAL_ERROR;
         }
@@ -1460,8 +1477,8 @@ public class SQLEvalVisitorUtils {
         if (a instanceof Byte || b instanceof Byte) {
             return castToByte(a) - castToByte(b);
         }
-        
-        if(a instanceof String && b instanceof String) {
+
+        if (a instanceof String && b instanceof String) {
             return castToLong(a) - castToLong(b);
         }
 
diff --git a/src/main/java/com/alibaba/druid/wall/spi/WallVisitorUtils.java b/src/main/java/com/alibaba/druid/wall/spi/WallVisitorUtils.java
index b50016ceba..c74deaf083 100644
--- a/src/main/java/com/alibaba/druid/wall/spi/WallVisitorUtils.java
+++ b/src/main/java/com/alibaba/druid/wall/spi/WallVisitorUtils.java
@@ -480,9 +480,6 @@ public class WallVisitorUtils {
     }
 
     public static Object getValue(SQLBinaryOpExpr x) {
-        x.getLeft().setParent(x);
-        x.getRight().setParent(x);
-
         if (x.getLeft() instanceof SQLName && x.getRight() instanceof SQLName) {
             if (x.getLeft().toString().equalsIgnoreCase(x.getRight().toString())) {
                 if (x.getOperator() == SQLBinaryOperator.Equality) {
diff --git a/src/test/java/com/alibaba/druid/bvt/filter/wall/WallStatTest_statMap.java b/src/test/java/com/alibaba/druid/bvt/filter/wall/WallStatTest_statMap.java
index e3fda025e3..ec064f70c9 100644
--- a/src/test/java/com/alibaba/druid/bvt/filter/wall/WallStatTest_statMap.java
+++ b/src/test/java/com/alibaba/druid/bvt/filter/wall/WallStatTest_statMap.java
@@ -1,5 +1,6 @@
 package com.alibaba.druid.bvt.filter.wall;
 
+import java.util.Calendar;
 import java.util.Collection;
 import java.util.Map;