if the column is indexed, it should only scan the rows included in the where clause

I agree, I think you will run into hardware limitations probably long before you run into software ones. Plus, I don't think there is a size limitation on the database so much as on a specific...

what do you mean by the database storage capacity?

what is your schema? do you have date fields in all the tables that need to be purged

well, first of all, you need a field that indicates whether they are administrator or not
i would suggest something like

admin tinyint NOT NULL Default 0

set it to 1 for administrators
...

well, depending on the situation, there are many ways you could do it, one would be:

tblFruit
fruitID int
fruitName varchar(25)

tblFruitSub1
Sub1ID int
fruitID int //foreign key to...

well, what does line 1 look like in your code

it's will be verydifficult to search every field of every table for the input.
I suggest doing something like a drop down box with which fields to search and then a text box with what to search for....

no problem. Let me know if you need any more help with them.

now for when you might want to do that.

Lets say you have started weekly and a monthly newsletter for this site, with the members having the option to sign up for either, neither or both.

Now...

left joins will return all rows in the initial table regardless of whether or not they have a corresponding entry in the joined table. for rows that do not have a corresponding entry, null will be...

http://www.w3schools.com/sql/default.asp

don't use mysql buth this works in ms-sql:

select t1.xid,t1.data1, t2.data2 from t1
right join t2 on
t1.xid = t2.xid

I don't use mysql but both of these work in ms-sql:
query 1:

declare @buyerid int
set @buyerid = 2
declare @creds int
declare @debs int

set @creds =(select sum(credits) from Transactions...

well to start off with, you are passing recaffected as a parameter to conn.execute, but you never set it to any value

can you do joins?

select * from t1
inner join t2 on t1.userid != t2.userid
inner join t3 on t1.userid !- t3.userid

upgrade to 4.1?

select username from t1 where username not in (select username from t2) and username not in (select username from t3)