mysql - UPDATE on duplicate columns when three are duplicate but not just one -
mysql - UPDATE on duplicate columns when three are duplicate but not just one -
i'm implementing mysql database uses x/y/z primary key structure, x , y foreign keys , z local key.
my predicament don't want duplicate case activated unless 3 duplicated. assuming have table structure.
x | y | z | description 34 | f4 | 25 | row 34 | f4 | 26 | row c6 | 71 | 9a | row
if wanted insert
x=34,y=f5,z=25,description=this row
it insert new row because although x , z duplicates, y not. however, if sent
x=34,y=f4,z=25,description=this first row
it should update entries description.
can insert ... on duplicate key, or there more complex needs done?
of course of study can. need declare (x,y,z
) primary or unique key:
create unique index idx_table_x_y_z on table(x, y, z)
if triplet exists in table, can utilize on duplicate key insert
.
mysql sql duplicates upsert
Comments
Post a Comment