diff --git a/CMakeLists.txt b/CMakeLists.txt
index 31536ca..b70e461 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -523,6 +523,6 @@ if(LEVELDB_INSTALL)
 endif(LEVELDB_INSTALL)
 
 add_executable(lab1_test
-        "${PROJECT_SOURCE_DIR}/test/lab1_test.cc"
+        "${PROJECT_SOURCE_DIR}/test/basic_function_test.cc"
 )
 target_link_libraries(lab1_test PRIVATE leveldb gtest)
diff --git a/db/db_impl.cc b/db/db_impl.cc
index 4a7d25c..49db131 100644
--- a/db/db_impl.cc
+++ b/db/db_impl.cc
@@ -1177,7 +1177,7 @@ std::vector<std::string> DBImpl::FindKeysByField(Field &field){
   std::vector<std::string> result;
     auto iter = NewIterator(ReadOptions());
     for(iter->SeekToFirst();iter->Valid();iter->Next()) {
-        std::string k = iter->key().ToString();
+        // std::string k = iter->key().ToString();
         InternalFieldArray fields(iter->value());
         if(fields.HasField(field)) {
             result.push_back(iter->key().ToString());
diff --git a/fielddb/encode_index.h b/fielddb/encode_index.h
new file mode 100644
index 0000000..eceeab4
--- /dev/null
+++ b/fielddb/encode_index.h
@@ -0,0 +1,37 @@
+#ifndef ENCODE_INDEX_H
+#define ENCODE_INDEX_H
+
+#include "leveldb/slice.h"
+#include "util/coding.h"
+namespace fielddb{
+using namespace leveldb;
+
+
+struct ParsedInternalIndexKey { //key : {name : val}
+  Slice user_key_;
+  Slice name_;
+  Slice val_;
+
+  ParsedInternalIndexKey() {} // Intentionally left uninitialized (for speed)
+  ParsedInternalIndexKey(const Slice& user_key, const Slice& name, const Slice& val)
+      : user_key_(user_key), name_(name), val_(val) {}
+};
+
+bool ParseInternalIndexKey(Slice input, ParsedInternalIndexKey* result);
+void AppendIndexKey(std::string* result, const ParsedInternalIndexKey& key);
+
+
+inline bool ParseInternalIndexKey(Slice input, ParsedInternalIndexKey* result){
+    return  GetLengthPrefixedSlice(&input, &result->name_) &&
+    GetLengthPrefixedSlice(&input, &result->val_) &&
+    GetLengthPrefixedSlice(&input, &result->user_key_);                                 
+}
+
+inline void AppendIndexKey(std::string* result, const ParsedInternalIndexKey& key){
+    PutLengthPrefixedSlice(result, key.name_);
+    PutLengthPrefixedSlice(result, key.val_);
+    PutLengthPrefixedSlice(result, key.user_key_);    
+}
+
+}
+#endif
\ No newline at end of file
diff --git a/fielddb/field_db.cpp b/fielddb/field_db.cpp
index d867411..637046e 100644
--- a/fielddb/field_db.cpp
+++ b/fielddb/field_db.cpp
@@ -6,7 +6,9 @@
 #include "leveldb/env.h"
 #include "leveldb/options.h"
 #include "leveldb/status.h"
+#include "db/write_batch_internal.h"
 #include "util/serialize_value.h"
+#include "fielddb/encode_index.h"
 
 namespace fielddb {
 using namespace leveldb;
@@ -18,6 +20,7 @@ Status FieldDB::OpenFieldDB(const Options& options,
         return Status::NotSupported(name, "new a fieldDb first\n");
     }
 
+    //
     Status status;
     DB *indexdb, *kvdb, *metadb;
     status = Open(options, name+"_indexDB", &indexdb);
@@ -77,6 +80,89 @@ std::vector<std::string> FieldDB::FindKeysByField(Field &field) {
     return kvDB_->FindKeysByField(field);
 }
 
+std::vector<std::pair<std::string, std::string>> FieldDB::FindKeysAndValByFieldName (
+                                                    const std::string &fieldName){
+    std::vector<std::pair<std::string, std::string>> result;
+    auto iter = kvDB_->NewIterator(ReadOptions());
+    std::string val;
+    for(iter->SeekToFirst();iter->Valid();iter->Next()) {
+        InternalFieldArray fields(iter->value());
+        val = fields.ValOfName(fieldName);
+        if(!val.empty()) {
+            result.push_back(std::make_pair(iter->key().ToString(), val));
+        }
+    }
+    return result;                                                    
+}
+
+Status FieldDB::CreateIndexOnField(const std::string& field_name) {
+    //taskQueue相关
+    //写锁 是不是只需要给putfields设置一把锁就行
+
+    std::vector<std::pair<std::string, std::string>> keysAndVal = 
+                                            FindKeysAndValByFieldName(field_name);
+    WriteBatch writeBatch; 
+    Slice value = Slice();   
+    for (auto &kvPair : keysAndVal){
+        std::string indexKey;
+        AppendIndexKey(&indexKey, 
+                        ParsedInternalIndexKey(kvPair.first, field_name, kvPair.second));
+        writeBatch.Put(indexKey, value);
+    }
+    Status s =  indexDB_->Write(WriteOptions(), &writeBatch);
+    if (!s.ok())    return s;
+
+    index_[field_name] = Exist;
+    //唤醒taskqueue
+
+}
+
+Status FieldDB::DeleteIndex(const std::string &field_name) {
+    //taskQueue相关
+    //写锁
+    std::vector<std::pair<std::string, std::string>> keysAndVal = 
+                                            FindKeysAndValByFieldName(field_name);
+    WriteBatch writeBatch;   
+    for (auto &kvPair : keysAndVal){
+        std::string indexKey;
+        AppendIndexKey(&indexKey, 
+                        ParsedInternalIndexKey(kvPair.first, field_name, kvPair.second));
+        writeBatch.Delete(indexKey);
+    }
+    Status s =  indexDB_->Write(WriteOptions(), &writeBatch);
+    if (!s.ok())    return s;
+
+    index_.erase(field_name);
+    //唤醒taskqueue
+}
+
+std::vector<std::string> FieldDB::QueryByIndex(const Field &field, Status *s) {
+    if (index_.count(field.first) == 0 || index_[field.first] != Exist){
+        *s = Status::NotFound(Slice());
+        return std::vector<std::string>();
+    }
+    std::string indexKey;
+    AppendIndexKey(&indexKey, 
+                    ParsedInternalIndexKey(Slice(), field.first, field.second));
+    Iterator *indexIterator = indexDB_->NewIterator(ReadOptions());
+    indexIterator->Seek(indexKey);
+
+    std::vector<std::string> result;
+    for (; indexIterator->Valid(); indexIterator->Next()) {
+        ParsedInternalIndexKey iterKey;
+        if (ParseInternalIndexKey(indexIterator->key(), &iterKey)){
+            if (iterKey.name_ == field.first && iterKey.val_ == field.second){
+                result.push_back(iterKey.user_key_.ToString());
+                continue; //查到说明在范围里，否则break
+            }
+        }
+        break;
+    }                
+
+    *s = Status::OK();
+    return result;
+}
+
 Iterator * FieldDB::NewIterator(const ReadOptions &options) {
     return kvDB_->NewIterator(options);
 }
diff --git a/fielddb/field_db.h b/fielddb/field_db.h
index 6a3c845..5c7e8d5 100644
--- a/fielddb/field_db.h
+++ b/fielddb/field_db.h
@@ -36,8 +36,8 @@ public:
     void CompactRange(const Slice *begin, const Slice *end) override;
 /*与索引相关*/
     Status CreateIndexOnField(const std::string& field_name);
-    Status DeleteIndex(std::string &field_name);
-    std::vector<std::string> QueryByIndex(Field &field, Status *s);
+    Status DeleteIndex(const std::string &field_name);
+    std::vector<std::string> QueryByIndex(const Field &field, Status *s);
 
     static Status OpenFieldDB(const Options& options,const std::string& name,FieldDB** dbptr);
 
@@ -57,10 +57,12 @@ private:
         Deleting,
         Exist
     };
-    std::map<std::string,int> index_;
+    std::map<std::string, int> index_;
     leveldb::port::Mutex mutex_; // mutex for taskqueue
     std::deque<Request *> taskqueue_;
 
+    std::vector<std::pair<std::string, std::string>> FindKeysAndValByFieldName (
+                                                    const std::string &fieldName);
 };
 } // end of namespace
 # endif
\ No newline at end of file
diff --git a/test/lab1_test.cc b/test/basic_function_test.cc
similarity index 74%
rename from test/lab1_test.cc
rename to test/basic_function_test.cc
index 7c9a50d..4915fe4 100644
--- a/test/lab1_test.cc
+++ b/test/basic_function_test.cc
@@ -81,7 +81,22 @@ void GetFieldData(FieldDB *db) {
 void findKeysByCity(FieldDB *db) {
   Field field = {"address", "Shanghai"};
   std::vector<std::string> resKeys = db->FindKeysByField(field);
-  // std::cout << shanghaiKeys.size() << " " << resKeys.size() << std::endl;
+  std::cout << shanghaiKeys.size() << " " << resKeys.size() << std::endl;
+  for (const std::string &key : resKeys){
+    ASSERT_NE(std::find(shanghaiKeys.begin(), shanghaiKeys.end(), key), shanghaiKeys.end());
+  }
+}
+
+void findKeysByCityIndex(FieldDB *db, bool expect) {
+  Field field = {"address", "Shanghai"};
+  Status s;
+  std::vector<std::string> resKeys = db->QueryByIndex(field, &s);
+  if (expect) ASSERT_TRUE(s.ok());
+  else {
+    ASSERT_TRUE(s.IsNotFound());
+    return;
+  }
+  std::cout << shanghaiKeys.size() << " " << resKeys.size() << std::endl;
   for (const std::string &key : resKeys){
     ASSERT_NE(std::find(shanghaiKeys.begin(), shanghaiKeys.end(), key), shanghaiKeys.end());
   }
@@ -99,6 +114,28 @@ TEST(TestLab1, Basic) {
     InsertFieldData(db);
     GetFieldData(db);    
     findKeysByCity(db);
+    delete db;
+}
+
+TEST(TestLab2, Basic) {
+    //destroy
+    FieldDB *db = new FieldDB();
+
+    if(OpenDB("testdb2", &db).ok() == false) {
+        std::cerr << "open db failed" << std::endl;
+        abort();
+    }
+    // ClearDB(db);
+    shanghaiKeys.clear();
+    InsertFieldData(db);
+    // GetFieldData(db);    
+    // findKeysByCity(db);
+    db->CreateIndexOnField("address");
+    findKeysByCityIndex(db, true);
+    db->DeleteIndex("address");
+    findKeysByCityIndex(db, false);
+
+    delete db;
 }
 
 
diff --git a/util/serialize_value.cc b/util/serialize_value.cc
index b93d8b7..562360b 100644
--- a/util/serialize_value.cc
+++ b/util/serialize_value.cc
@@ -73,6 +73,22 @@ bool InternalFieldArray::HasField(const Field& field) {
     return std::find(fields.begin(),fields.end(),field) != fields.end();
 }
 
-
+std::string InternalFieldArray::ValOfName(const std::string &name) {
+    if(isMapped) {
+        if(map.count(name)) {
+            return map[name];
+        }
+        return std::string();
+    }
+    
+    for (auto iter = fields.begin(); iter != fields.end(); iter++){
+        if (iter->first == name) {
+            return iter->second;
+        } else if (iter->first > name) {
+            return std::string();
+        }
+    }
+    return std::string();
+}
 
 }
\ No newline at end of file
diff --git a/util/serialize_value.h b/util/serialize_value.h
index a1ca30a..b769fb8 100644
--- a/util/serialize_value.h
+++ b/util/serialize_value.h
@@ -48,7 +48,7 @@ public:
     std::string Serialize();
 
     bool HasField(const Field& field);
-
+    std::string ValOfName(const std::string& name);
 
 private:
     bool isMapped;