-- create table users(   --     username nvarchar(50) not null primary key,   --     password nvarchar(50) not null,   --     enabled bit not null);   --create table authorities (  --      username nvarchar(50) not null,  --      authority nvarchar(50) not null,  --      constraint fk_authorities_users foreign key(username) references users(username));  --      create unique index ix_auth_username on authorities (username,authority);  create table groups (    [id] [bigint] IDENTITY (0, 1) NOT NULL primary key,     group_name nvarchar(50) not null);  create table group_authorities (    group_id bigint not null,     authority nvarchar(50) not null,     constraint fk_group_authorities_group foreign key(group_id) references groups(id));  create table group_members (     [id] [bigint] IDENTITY (0, 1) NOT NULL primary key,     username nvarchar(50) not null,     group_id bigint not null,     constraint fk_group_members_group foreign key(group_id) references groups(id));