Inner join drops null values example(Python)

df_orders = spark.createDataFrame([('Nissan','Altima','2-door 2.5 S Coupe'), ('Nissan','Altima','4-door 3.5 SE Sedan'), ('Nissan','Altima',''), ('Nissan','Altima', None)], ["Company", "Model", "Info"])

display(df_orders)

df_models = spark.createDataFrame([('Nissan','Altima',''), ('Nissan','Altima','2-door 2.5 S Coupe'), ('Nissan','Altima','2-door 3.5 SE Coupe'), ('Nissan','Altima','4-door 2.5 S Sedan'), ('Nissan','Altima','4-door 3.5 SE Sedan'), ('Nissan','Altima','4-door 3.5 SL Sedan'), ('Nissan','Altima','4-door HYBRID Sedan'), ('Nissan','Altima',None)], ["Company", "Model", "Info"])

display(df_models)

df_orders.createOrReplaceTempView("Orders")

df_models.createOrReplaceTempView("Models")

%sql

SELECT * 

FROM Orders a

INNER JOIN Models b 

ON a.Company = b.Company 

AND a.Model = b.Model 

AND a.Info = b.Info