improved sql parser.

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

@@ -1960,4 +1960,8 @@ public class Lexer {
 
         return buf.toString();
     }
+
+    public String getSource() {
+        return text;
+    }
 }

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

@@ -310,7 +310,7 @@ public class SQLSelectParser extends SQLParser {
         return withQueryClause;
     }
 
-    protected void parseWhere(SQLSelectQueryBlock queryBlock) {
+    public void parseWhere(SQLSelectQueryBlock queryBlock) {
         if (lexer.token == Token.WHERE) {
             lexer.nextToken();
 

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

@@ -22,6 +22,7 @@ import com.alibaba.druid.sql.ast.*;
 import com.alibaba.druid.sql.ast.expr.*;
 import com.alibaba.druid.sql.ast.statement.*;
 import com.alibaba.druid.sql.ast.statement.SQLCreateTriggerStatement.TriggerType;
+import com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlSelectQueryBlock;
 import com.alibaba.druid.sql.dialect.oracle.parser.OracleExprParser;
 import com.alibaba.druid.util.FnvHash;
 import com.alibaba.druid.util.JdbcConstants;