I want to connect to a GCP database using Cloud Spanner and PostgreSQL Interface from a go language

[shintaro_nov]

I have an application created with go language,Docker.

I want to connect to the GCP database from my local environment using Cloud Spanner and PostgreSQL Interface, but I don't know how to do it. 

I have looked at the official introduction, but the sample code is complicated and difficult to imitate.

 I would like to know how to create my own application from scratch and how to connect it to the GCP database.

Also, I am currently taking advantage of the free period to try the connection.

I know you are busy, but I would appreciate your response.

[ms4446]

Sure, I'd be happy to help you get started! I'll break down the process into a few steps.

1. Install the Cloud Spanner PostgreSQL Interface client library for Go. The client library provides methods to connect to and interact with your Spanner database using SQL. You can install it with the following command:

   go get cloud.google.com/go/spanner

2. Set up authentication. To connect to your GCP database, you need to authenticate your application. The simplest way is to use the GOOGLE_APPLICATION_CREDENTIALS environment variable, which should be set to the path of your service account JSON key file. If you don't have a service account, you can create one from your GCP console. Once you have the JSON key file, you can set the environment variable:

   export GOOGLE_APPLICATION_CREDENTIALS="/path/to/keyfile.json"

3. Create a Spanner client. Once your authentication is set up, you can create a new Spanner client in your Go application:

   package main import ( "cloud.google.com/go/spanner" "context" "log" ) func main() { ctx := context.Background() // Replace this with your Spanner database's connection string. db := "projects/PROJECT_ID/instances/INSTANCE_ID/databases/DATABASE_ID" client, err := spanner.NewClient(ctx, db) if err != nil { log.Fatal(err) } defer client.Close() // Now you can use `client` to interact with your database. }

4. Interact with your database. You can use the client object to run SQL queries, read data, and modify your database. Here's an example of how you can run a SQL query:

   _, err = client.ReadWriteTransaction(ctx, func(ctx context.Context, txn *spanner.ReadWriteTransaction) error { _, err := txn.Update(ctx, spanner.Statement{SQL: "UPDATE MyTable SET MyColumn = 'New Value' WHERE Id = 1"}) return err }) if err != nil { log.Fatal(err) }

This is a very basic example, but it should get you started with connecting to your GCP database using Cloud Spanner and the PostgreSQL interface from a Go application. 

For Docker, you would need to use a Dockerfile to create a Docker image of your application. You can set the GOOGLE_APPLICATION_CREDENTIALS environment variable in your Dockerfile using the ENV instruction, and make sure to copy your service account key file into the Docker image.

I hope this helps! Let me know if you have any questions.

[shintaro_nov]

Thanks for the reply!

With your advice, I was able to INSERT the data into gcp postgresSQL.

Thank you for your continued support!