fixed 2800d109 from https://gitee.com/Annie_wang/docs/pulls/18490

update docs
Signed-off-by: NAnnie_wang <annie.wangli@huawei.com>

en/application-dev/database/data-persistence-by-kv-store.md

@@ -35,7 +35,6 @@ The following table lists the APIs used for KV data persistence. Most of the API
 1. Create a **KvManager** instance to manage database objects. 
 
    Example:
-
    Stage model:
 
      
@@ -95,12 +94,11 @@ The following table lists the APIs used for KV data persistence. Most of the API
 2. Create and obtain a KV store. 
      
    Example:
-
    ```js
    try {
      const options = {
        createIfMissing: true, // Whether to create a KV store when the database file does not exist. By default, a KV store is created.
-       createIfMissing: true, // Whether to encrypt database files. By default, database files are not encrypted.
+       encrypt: false, // Whether to encrypt the KV store. By default, KV stores are not encrypted.
        backup: false, // Whether to back up database files. By default, the database files are backed up.
        autoSync: true, // Whether to automatically synchronize database files. The value **true** means to automatically synchronize database files; the value **false** (default) means the opposite.
        kvStoreType: distributedKVStore.KVStoreType.SINGLE_VERSION, // Type of the KV store to create. By default, a device KV store is created.
@@ -123,7 +121,6 @@ The following table lists the APIs used for KV data persistence. Most of the API
 3. Use **put()** to add data to the KV store. 
      
    Example:
-
    ```js
    const KEY_TEST_STRING_ELEMENT = 'key_test_string';
    const VALUE_TEST_STRING_ELEMENT = 'value_test_string';
@@ -147,7 +144,6 @@ The following table lists the APIs used for KV data persistence. Most of the API
 4. Use **get()** to obtain the value of a key. 
      
    Example:
-
    ```js
    const KEY_TEST_STRING_ELEMENT = 'key_test_string';
    const VALUE_TEST_STRING_ELEMENT = 'value_test_string';
@@ -174,7 +170,6 @@ The following table lists the APIs used for KV data persistence. Most of the API
 5. Use **delete()** to delete the data of the specified key. 
      
    Example:
-
    ```js
    const KEY_TEST_STRING_ELEMENT = 'key_test_string';
    const VALUE_TEST_STRING_ELEMENT = 'value_test_string';