java.sql.SQLIntegrityConstraintViolationException: Column 'language_id' cannot be null

Question

In an attempt to make a Java servlet to implement add functionality, the following error shows up in the console of Eclipse:

java.sql.SQLIntegrityConstraintViolationException: Column 'language_id' cannot be null

Written below is my attempt of preparing the PreparedStatement

PreparedStatement ps=con.prepareStatement(
        "INSERT INTO film (title,release_year,special_features,rating,description,language_id)"  +
        " VALUES (?,?,?,?,?,(SELECT language_id FROM `language` WHERE `name`=?));");
        
ps.setString(1,titleValue);  
ps.setString(2,releaseYearValue); 
ps.setString(3,specialFeaturesValue);
ps.setString(4,ratingsValue);
ps.setString(5,descriptionValue);
ps.setString(6,languageValue);

int i = ps.executeUpdate();

The table structure in MySQL DB is as follows:

FILM TABLE -> title | description | special_features | release_year | rating | language_id

LANGUAGE TABLE -> language_id | name

The language_id of FILM table is the foreign key of the language_id primary column of LANGUAGE table