fix: introduce PreciseTimestamp to fix mysql datetime precision issue.

[Colstuwjx]

Fixed #480

Generated mysql table:

mysql> desc events;
+----------------------------+---------------+------+-----+---------+-------+
| Field                      | Type          | Null | Key | Default | Extra |
+----------------------------+---------------+------+-----+---------+-------+
| id                         | varchar(128)  | NO   | PRI | NULL    |       |
| app_name                   | varchar(128)  | NO   | PRI | NULL    |       |
| user_id                    | varchar(128)  | NO   | PRI | NULL    |       |
| session_id                 | varchar(128)  | NO   | PRI | NULL    |       |
| invocation_id              | varchar(256)  | NO   |     | NULL    |       |
| author                     | varchar(256)  | NO   |     | NULL    |       |
| branch                     | varchar(256)  | YES  |     | NULL    |       |
| timestamp                  | datetime(6)   | NO   |     | NULL    |       |
| content                    | longtext      | YES  |     | NULL    |       |
| actions                    | blob          | NO   |     | NULL    |       |
| long_running_tool_ids_json | text          | YES  |     | NULL    |       |
| grounding_metadata         | longtext      | YES  |     | NULL    |       |
| partial                    | tinyint(1)    | YES  |     | NULL    |       |
| turn_complete              | tinyint(1)    | YES  |     | NULL    |       |
| error_code                 | varchar(256)  | YES  |     | NULL    |       |
| error_message              | varchar(1024) | YES  |     | NULL    |       |
| interrupted                | tinyint(1)    | YES  |     | NULL    |       |
+----------------------------+---------------+------+-----+---------+-------+
17 rows in set (0.24 sec)

Event data from api:

{
    "id": "c4070feb-f210-486b-a410-aa0fcf9f6360",
    "appName": "chatbot_app",
    "userId": "user",
    "state": {},
    "events": [
        {
            "content": {
                "parts": [
                    {
                        "text": "hi"
                    }
                ],
                "role": "user"
            },
            "invocationId": "e-919a300a-758a-49da-96ae-4b4ab6ee4a76",
            "author": "user",
            "actions": {
                "stateDelta": {},
                "artifactDelta": {},
                "requestedAuthConfigs": {}
            },
            "longRunningToolIds": [],
            "id": "nNwEB5e0",
            "timestamp": 1748490022.719857
        },
        {
            ...
            "actions": {
                "stateDelta": {},
                "artifactDelta": {},
                "requestedAuthConfigs": {}
            },
            "longRunningToolIds": [],
            "id": "wPo1Cn4L",
            "timestamp": 1748490025.788181
        },
        {
            ...
            "actions": {
                "stateDelta": {},
                "artifactDelta": {},
                "transferToAgent": "probing_agent",
                "requestedAuthConfigs": {}
            },
            "longRunningToolIds": [],
            "id": "9NWoeTr6",
            "timestamp": 1748490032.351483
        },
        {
           ...
            "actions": {
                "stateDelta": {},
                "artifactDelta": {},
                "requestedAuthConfigs": {}
            },
            "longRunningToolIds": [],
            "id": "9b1mu6u9",
            "timestamp": 1748490035.395766
        }
    ],
    "lastUpdateTime": 1748475639.0
}

Thanks.

[DeanChensj]

Could you format the code with https://github.com/google/adk-python/blob/main/autoformat.sh?

[Colstuwjx]

Could you format the code with https://github.com/google/adk-python/blob/main/autoformat.sh?

@DeanChensj done, thanks.

[Colstuwjx]

not sure why the UT failed, seems like the latest merged commit also has this issue

[DeanChensj]

There was a issue blocking new changes from google internal syncing to the github, it is now resolved. Right now there is still unit tests failing irrelevant to your change.

[DeanChensj]

merged in 841e10a