Database Management
Reference Manual
Database Navigation and Query Syntax
:
Specify a Relative Position in the Hierarchy
: Move to Next Lower Level
Move to Next Lower Level
The syntax for moving down a level shares much of the syntax for moving within the level.
Int
descend to nth child
First Member
Goes to 1
st
member
Last Member
Goes to last member
First <element type>,
FirstMember<element type>
Goes to first member of given type
First int <element type>
Go to nth element of given type in members list
Last <element type>,
LastMember<element type>
Goes to last member of given type
Last int <element type>
Go to nth last element of given type in members list
Next <element type>
Goes to next element in member list from current position
Next int <element type>
Goes to next nth element in member list of given type from current position
Prev <element type>
Goes to next element in member list from current position
Prev int <element type>
Goes to previous nth element in member list of given type from current position
<element type> int
descend to nth child of given type
Example
We can use the same example as before but in this case we are positioned at the owning equipment, say /MYEQUI. The current position is defaulted to the start of the list. The member list being:
1 BOX /MyBoxA
2 CYL /MyCylA
3 CYL /MyCylB
4 RTOR /MyRtorA
5 CYL /MyCylC
6 BOX /MyBoxB
7 BOX /MyBoxC
8 CYL /MyCylD
9 BOX /MyBoxD
5
Moves CE to /MyCylC (5
th
member)
FIRST MEMBER
Moves CE to /MyBoxA
LAST MEMBER
Moves CE to /MyBoxD
FIRST CYL
Moves CE to /MyCylA
FIRST 3 CYL
Moves CE to /MyCylC
LAST CYL
Moves CE to /MyCylD
LAST 2 CYL
Moves CE to /MyCylC
NEXT CYL
Moves CE to /MyCylA (same as FIRST CYL)
NEXT 2 CYL
Moves CE to /MyCylB (same as FIRST 2 CYL)
PREV CYL
Invalid as there are no cylinders before the current position
BOX 4
Moves CE to /MYBoxD
In the above examples, the use of NEXT had the same result as using FIRST. The use of PREV was invalid. This is because the current position was off the start. We can change the current position using the END syntax to give more meaningful examples
e.g.
/MyCylB
END
The CE is /MyEqui as before, but with the current position at /MyCylB
NEXT CYL
Moves CE to /MyCylC
NEXT 2 CYL
Moves CE to /MyCylD
PREV CYL
Moves CE to /MyCylA
1974 to current year.
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