I would like to make usage of the beta database link feature but encounter many difficulty to make the link. I follow instruction on https://community.visualdatatools.com/datagraph/knowledge-base/database/ but setup remain unsuccessful. I am trying to connect to an existing database. Let assume that I do not have writing access to this database. When I look at the database connection log, I got ‘Failed’ message with ‘Empty’ response at connection level (i.e. the connection isn’t established but I do not have any information on the possible error).
I have few question to try to understand what I could do wrong :
I check the script was properly copied on the remote server and accessible from external web browser. The the issue isn’t related to missing php script or un-accessible php script
n the database link configuration, on the field database, what should be the host : The http web server address or the pod database server ? What if http server and database server are the same.
After reading the php script which was properly copied to the remote http server (the same one that is hosting the database), I have several question :
Your php script is trying to read dg_admin_* table onto the database I am trying to access. I understand that those table are Datagraph specific table to handle permission. What if those table do not exist in the remote database ?
I see later that the script is creating those dg_admin_* table. But what if I connect to the database with a ‘read only’ role ?
Who will be the owner of those newly created table ?
You mention that Datagraph support MySQL and Postgres but I found some issue in your script that may be trouble for Postgres database (I am not specialist on pgSQL but testing your query with the shell I got error message or empty reply):
to get the list of table, I would used, for Postgres : SELECT table_name FROM information_schema.tables WHERE table_type = ‘BASE TABLE’ AND table_schema=’public’ (replacing $dbname by public)
When you create the pg_admin table, I would replace ‘int NOT NULL AUTO_INCREMENT’ by ‘SERIAL NOT NULL’ as PGsql seems not to understand AUTO_INCREMENT
I got error relative to tenant
I got error type “pg_catalog.varchar_utf8” does not exist
I did some manual modification of the script but this did not solve the initial issue. So, the error might be hidden elsewhere I did not found. Any help would be welcome.