CREATE TABLE t1 (
id           VARCHAR(255) NOT NULL PRIMARY KEY,
sujet        VARCHAR(255),
motsclefs    TEXT,
texte        MEDIUMTEXT,
FULLTEXT(sujet, motsclefs, texte)
);
INSERT INTO t1 VALUES('123','toto','essai','test');
INSERT INTO t1 VALUES('456','droit','penal','lawyer');
INSERT INTO t1 VALUES('789','aaaaa','bbbbb','cccccc');
CREATE TABLE t2 (
id         VARCHAR(255) NOT NULL,
author     VARCHAR(255) NOT NULL
);
INSERT INTO t2 VALUES('123', 'moi');
INSERT INTO t2 VALUES('123', 'lui');
INSERT INTO t2 VALUES('456', 'lui');
select match(t1.texte,t1.sujet,t1.motsclefs) against('droit')
from t1 left join t2 on t2.id=t1.id;
match(t1.texte,t1.sujet,t1.motsclefs) against('droit')
0
0
0.67003107070923
0
drop table t1, t2;