multiple inserts and deletes

[baruch]

Hello all,

I'm using PHP/mySQL couple :) to insert and delete some informations
based on some criterium and I don't like to look at my code full of
FOR and IF's.

1)
Example: In a list of ID's 1 4 5 7 8 9 20 34 56 is possible to send an
UNIQUE command to mysql to delete the Id's 5, 7, 20, etc? Need I put a
ugly query like "Delete ... WHERE id=5 AND id=7 AND id=20" ad
infinitum?

2) How can I check without loops if a given value exist in the table?
Example: id's 1 3 5 7 8 must be inserted ONLY IF 3 or 5 doesn't exist.

Finally, It's very hard to do some search for examples to know how to
use the keyword "IN" , any hint please?

Thank you all and I'm sorry for the long post.

[Aggro]

baruch wrote:

1)
Example: In a list of ID's 1 4 5 7 8 9 20 34 56 is possible to send an
UNIQUE command to mysql to delete the Id's 5, 7, 20, etc? Need I put a
ugly query like "Delete ... WHERE id=5 AND id=7 AND id=20" ad
infinitum?
delete from tablename where id in(5,7,20);
2) How can I check without loops if a given value exist in the table?
Example: id's 1 3 5 7 8 must be inserted ONLY IF 3 or 5 doesn't exist.

# I'm not sure if you can do this with only one query,
# but with two queries
select * from table where id in(3,5);

# if previous didn't return any rows:
insert into yourtable(id) values(1),(3),(5),(7);

[Aggro]

baruch wrote:

1)
Example: In a list of ID's 1 4 5 7 8 9 20 34 56 is possible to send an
UNIQUE command to mysql to delete the Id's 5, 7, 20, etc? Need I put a
ugly query like "Delete ... WHERE id=5 AND id=7 AND id=20" ad
infinitum?
delete from tablename where id in(5,7,20);
2) How can I check without loops if a given value exist in the table?
Example: id's 1 3 5 7 8 must be inserted ONLY IF 3 or 5 doesn't exist.

# I'm not sure if you can do this with only one query,
# but with two queries
select * from table where id in(3,5);

# if previous didn't return any rows:
insert into yourtable(id) values(1),(3),(5),(7);

[Aggro]

baruch wrote:

1)
Example: In a list of ID's 1 4 5 7 8 9 20 34 56 is possible to send an
UNIQUE command to mysql to delete the Id's 5, 7, 20, etc? Need I put a
ugly query like "Delete ... WHERE id=5 AND id=7 AND id=20" ad
infinitum?
delete from tablename where id in(5,7,20);
2) How can I check without loops if a given value exist in the table?
Example: id's 1 3 5 7 8 must be inserted ONLY IF 3 or 5 doesn't exist.

# I'm not sure if you can do this with only one query,
# but with two queries
select * from table where id in(3,5);

# if previous didn't return any rows:
insert into yourtable(id) values(1),(3),(5),(7);

[baruch]

> delete from tablename where id in(5,7,20);
[..]

Thank you very much!

[baruch]

> delete from tablename where id in(5,7,20);
[..]

Thank you very much!

[baruch]

> delete from tablename where id in(5,7,20);
[..]

Thank you very much!