bug fixed for SchemaStat

src/main/java/com/alibaba/druid/stat/TableStat.java

@@ -202,6 +202,14 @@ public class TableStat {
             }
 
             Name other = (Name) o;
+            
+            if (this.name == other.name) {
+                return true;
+            }
+            
+            if (this.name == null | other.name == null) {
+                return false;
+            }
 
             return this.name.equalsIgnoreCase(other.name);
         }

src/test/java/com/alibaba/druid/bvt/sql/mysql/MySqlSelectTest_27.java

@@ -0,0 +1,70 @@
+/*
+ * Copyright 1999-2101 Alibaba Group Holding Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.alibaba.druid.bvt.sql.mysql;
+
+import java.util.List;
+
+import org.junit.Assert;
+
+import com.alibaba.druid.sql.MysqlTest;
+import com.alibaba.druid.sql.SQLUtils;
+import com.alibaba.druid.sql.ast.SQLStatement;
+import com.alibaba.druid.sql.dialect.mysql.parser.MySqlStatementParser;
+import com.alibaba.druid.sql.dialect.mysql.visitor.MySqlSchemaStatVisitor;
+
+public class MySqlSelectTest_27 extends MysqlTest {
+
+    public void test_0() throws Exception {
+        String sql = "SELECT /*+ READ_CONSISTENCY(WEAK) */ NOW() AS db_time FROM DUAL";
+
+        
+        MySqlStatementParser parser = new MySqlStatementParser(sql);
+        List<SQLStatement> statementList = parser.parseStatementList();
+        SQLStatement stmt = statementList.get(0);
+//        print(statementList);
+
+        Assert.assertEquals(1, statementList.size());
+
+        MySqlSchemaStatVisitor visitor = new MySqlSchemaStatVisitor();
+        stmt.accept(visitor);
+
+//        System.out.println("Tables : " + visitor.getTables());
+//        System.out.println("fields : " + visitor.getColumns());
+//        System.out.println("coditions : " + visitor.getConditions());
+//        System.out.println("orderBy : " + visitor.getOrderByColumns());
+        
+        Assert.assertEquals(1, visitor.getTables().size());
+        Assert.assertEquals(0, visitor.getColumns().size());
+        Assert.assertEquals(0, visitor.getConditions().size());
+        Assert.assertEquals(0, visitor.getOrderByColumns().size());
+        
+        {
+            String output = SQLUtils.toMySqlString(stmt);
+            Assert.assertEquals("SELECT /*+ READ_CONSISTENCY(WEAK) */ NOW() AS db_time"
+                    + "\nFROM DUAL", //
+                                output);
+        }
+        {
+            String output = SQLUtils.toMySqlString(stmt, SQLUtils.DEFAULT_LCASE_FORMAT_OPTION);
+            Assert.assertEquals("select /*+ READ_CONSISTENCY(WEAK) */ NOW() as db_time"
+                    + "\nfrom DUAL", //
+                                output);
+        }
+    }
+    
+    
+    
+}