Question

When and how do I need to use groups in query

Answer 1

 

 

a grouping is only needed when there is an OR in the Query,

wen we use an OR anywhere in the Query we need to tell the program what condtions need to be met, with out a grouping it will load the records that satisfy any conditions are met, 

so lets take an example

we always want parents only but the parents need to have one of the these three conditions  Payments Or Credit cards Or Flag, so a grouping would look like this

Parents And ( Payments Or Credit cards Or Flag) 

a very simple example in math would be 

 2 * (6 + 5)

 (2 * 6 )+ 5

you can see the grouping decides how the criteria should be evaluated