Cannot Import the *.bak to GCP Cloud SQL due to compatibility level

This question is mine from Stackoverflow for long time. Now I want to re-post here for anyone who want to reference.

I workd with Google Cloud Platform a few months, when moving the Lad from local to the CLoud, this issue is one of them that I faced.

My local SQL Server 2014, version: 120
GCP SQL Cloud Instance, running SQL Server 2017 Standard/Enterprise

Issue:

At the time, May 25th 2021, When performing importing the *.BAK to the GCP SQL Cloud, the SQL Cloud Instance is running SQL Server 2017 Standard,
I’m getting this error:

ERROR: (gcloud.sql.import.bak) [ERROR SQL SERVER EXTERNAL WARNING] 120 is not a supported compatibility level. Supported: [140, 130, 120, 110, 100]

Although my exporting server running 120 , checked by this query:

SELECT compatibility_level
FROM sys.databases
WHERE name = 'mydb-name';

and this query:

SELECT @@version

The response said:

Microsoft SQL Server 2014 (SP3-CU4) – 12.0.6329.1 (X64) Enterprise Edition

Here’re my steps:

Exporting the BAK file from my server (120 version)
Create the SQL instance with SQL Server 2017 Standard, also created the user login (same as my exporting server)
Perform the import command:

cloud beta sql import bak my-sql-instance gs://my-bucket/file.bak --database=mydb-name

I have also tried with the Cloud SQL Enterprise but no luckily. All of them shown the error:

Solution

Since no one answer my question on stackoverflow, may be no one faced this issue, so I would like to update the solution for anyone who want to reference.

Import the *.bak to the server which is running SQL Server version >120, ex SQL Server 2016 or newer.
Do the Upgrade Db compatible level to >120
After that, do the backup the Db from this server
Using the GCP command to import again/Perform the import from GCP Console.

gcloud beta sql import bak my-sql-instance gs://my-bucket/file.bak --database=mydb-name