create table Document
(
   TextId                         int                            not null AUTO_INCREMENT,
   Caption                        varchar( 255 )                   not null,
   primary key (TextId)
);
create table DocumentWord
(
   TextId                         int                            not null,
   WordId                         int                            not null,
   Seq                            bigint                         not null,
   primary key (TextId, WordId, Seq)
);
create index Text_Words_FK on DocumentWord
(
   TextId
);
create index DocWords_FK on DocumentWord
(
   WordId
);

create table Relation
(
   RelationId                     int                            not null AUTO_INCREMENT,
   Name                           varchar( 255 )                   not null,
   primary key (RelationId)
);
create table Word
(
   WordId                         int                            not null AUTO_INCREMENT,
   Word                           varchar( 255 )                   not null,
   primary key (WordId)
);
create table WordRelation
(
   RelationId                     int                            not null,
   Word1Id                        int                            not null,
   Word2Id                        int                            not null,
   primary key (RelationId, Word1Id, Word2Id)
);
create index Relationship_Type_FK on WordRelation
(
   RelationId
);
create index Word1_FK on WordRelation
(
   Word1Id
);
create index Word2_FK on WordRelation
(
   Word2Id
);

alter table DocumentWord add constraint FK_DocWords foreign key (WordId)
      references Word (WordId);

alter table DocumentWord add constraint FK_Text_Words foreign key (TextId)
      references Document (TextId);

alter table WordRelation add constraint FK_Relationship_Type foreign key (RelationId)
      references Relation (RelationId);

alter table WordRelation add constraint FK_Word1 foreign key (Word1Id)
      references Word (WordId);

alter table WordRelation add constraint FK_Word2 foreign key (Word2Id)
      references Word (WordId);