Sharing database instance between DatabaseLibrary and custom library

Libraries
1

I want to implement a set of regression tests as SQL queries by using the DatabaseLibrary, with a sqlite3 in-memory DB.

*** Settings ***
Library        DatabaseLibrary

*** Test Cases ***
Test Sqlite
    Connect To Database    sqlite3    database=:memory:

The base for the database are stored in some CSV files. Those will be imported by

    Import Csv Into    table1    table1.csv

I wanted to use pandas to load the CSVs into some tables by using a custom library in python:

import pandas as pd
import sqlite3

def import_csv_into(self, table_name, csv_path):
  conn = sqlite3.connect(':memory:')
  csv_df = pd.read_csv(csv_path)
  csv_df.to_sql(table_name, conn, if_exists='replace', index=False)

Of course, the two are not using the same sqlite3 instance, therefore the data loaded by the custom library are not available to the DatabaseLibrary so that the following will fail:

${rows}=    Query    select COUNT(*) from table1

Is there a way to “share” the same sqlite3 connection instance between the two libraries?

Thanks,
Christian

2

I already found an option, adding it here for other’s reference:

To “share” the same sqlite3 instance between both libraries I used the following (inspired by Passing an object to another class - #12 by Mavnus04 )

import pandas as pd
from robot.libraries.BuiltIn import BuiltIn

def import_csv_into(self, table_name, csv_path):
  databaseLibrary = BuiltIn().get_library_instance(‘DatabaseLibrary’)
  conn = databaseLibrary.connection_store.get_connection(None).client

  csv_df = pd.read_csv(csv_path)
  csv_df.to_sql(table_name, conn, if_exists='replace', index=False)

It will get the default/ currently selected database connection and passes it to read_csv. BTW, this also abstracts the new keyword from sqlite3.

General question: Is this the right way to do this or is there any better way which does not require to access the internal structure of the DatabaseLibrary?

Thanks,
Christian

1 Like
3

Using BuiltIn to fetch the instance is one option, another one if creating a custom library that subclasses DatabaseLibrary and adds the desired keywords to it. Since DatabaseLibrary is a stable release, I’d be inclined to go with that option, personally.

1 Like
4

Good idea, this is also an option. In my case, as it was the first occurrence of this requirement, I simply added the function / keyword into the already existing custom library. But your option looks smarter as this would encapsulate the enhancement into a generic custom library.