Is it possible providerUserId be null ? (dbcUsersConnectionRepository.sql)

[tezavrat]

Is it possible providerUserId be null ?

create table UserConnection (userId varchar(255) not null,
providerId varchar(255) not null,
providerUserId varchar(255),
rank int not null,
displayName varchar(255),
profileUrl varchar(512),
imageUrl varchar(512),
accessToken varchar(255) not null,
secret varchar(255),
refreshToken varchar(255),
expireTime bigint,
primary key (userId, providerId, providerUserId));
create unique index UserConnectionRank on UserConnection(userId, providerId, rank);

Why are you not providing scripts for MySql ?

[tezavrat]

"create unique index UserConnectionRank on UserConnection(userId, providerId, rank)";
maybe it should be
"create unique index ProviderIdAndProviderUserId on UserConnection(providerId, providerUserId)" to have unique connections ?