Erreur SQL !
SELECT * FROM flux_actu WHERE theme_src="france" and id_flux_actu="521714$article=crise-a-la-mairie-de-saint-nazaire-apres-des-accusations-de-violences-sexuelles" UNION (SELECT * FROM flux_sport WHERE theme_src="france" and id_flux_sport="521714$article=crise-a-la-mairie-de-saint-nazaire-apres-des-accusations-de-violences-sexuelles") UNION (SELECT * FROM flux_tech WHERE theme_src="france" and id_flux_tech="521714$article=crise-a-la-mairie-de-saint-nazaire-apres-des-accusations-de-violences-sexuelles") UNION (SELECT * FROM flux_foot WHERE theme_src="france" and id_flux_foot="521714$article=crise-a-la-mairie-de-saint-nazaire-apres-des-accusations-de-violences-sexuelles")