[Mysql] ricavare data primo lunedì del mese

[piero.mac]

visto che vuoi tutta la data...

SELECT 
concat(
if( (10 - dayofweek('2006-08-01')) <= 7 , 
     10 - dayofweek('2006-08-01'), 
      3 - dayofweek('2006-08-01') ), 
  '-08-2006') as first_monday