SELECT t.Fecha as fecha,
sum(t.Casos)::Int as casos,
sum(t28.Casos)::Int as casos28,
sum(t25.Casos)::Int as casos25,
sum(t21.Casos)::Int as casos21,
sum(t18.Casos)::Int as casos18,
COALESCE((sum(t28.Casos)::Int - sum(t21.Casos)::Int), sum(t28.Casos)::Int) as dif28_21
FROM notificacionSintomas t
LEFT JOIN notificacionSintomas20220528 t28
ON t.Fecha = t28.Fecha AND t.Categoria = t28.Categoria AND t.Serie = t28.Serie
LEFT JOIN notificacionSintomas20220525 t25
ON t.Fecha = t25.Fecha AND t.Categoria = t25.Categoria AND t.Serie = t25.Serie
LEFT JOIN notificacionSintomas20220521 t21
ON t.Fecha = t21.Fecha AND t.Categoria = t21.Categoria AND t.Serie = t21.Serie
LEFT JOIN notificacionSintomas20220518 t18
ON t.Fecha = t18.Fecha AND t.Categoria = t18.Categoria AND t.Serie = t18.Serie
WHERE t.Categoria = 'Fecha notificación' AND (t.Serie = 'confirmada' OR t.Serie = 'no notificada' OR t.Serie = 'probable')
GROUP BY t.Fecha
ORDER BY t.Fecha DESC