SQR Qick Reference

1.       What is the program flow of SQR?

When SQR Program starts executing. There are two stages in the Program Flow.

1) Compile stage

2) Execution Stage

 Compile Stage.

All the Preprocessor directives are compiled (which starts with #include).

Ex: All the SQC are run.

Check for the syntax errors for the conditions.

Ex: if for loop while loop are properly ended with the respective syntax.

Allocates memory structure if you are using the Arrays and load look up .

 Execution stage:

Starts interpreting the code line by line.

Check for the begin -program body.

Begin -heading.

Begin- footer.

2.       What are the compulsory SQC's that should be used in SQR Program?

There are no required SQCs unless procedures (functions) are being used in the main program that requires them. setenv.sqc, prcsapi.sqc and prcsdef.sqc are required if you want to schedule the job using PS process scheduler.

3. What is difference between Load Look up and Array

Load Lookup is essentially an array which acts in the form of a table. Load Lookup is used to reduce the complexity of joins - it populates the values of a certain field depending on the key field specified from a certain table. Then the users can query from the preloaded lookup table instead of joining tables.
While arrays are used to store and retrieve data using the get and put commands

Example for load lookup

load-lookup

name=states

rows=50

table=stateabbrs

key=abbr

return_value=name

where=country='USA'

to retrieve value from the load lookup we use

lookup states $state $name

to declare an array

syntax

create-array  name=custs size=100

   field=name:char

   field=no:number

   field=state:char

   field=zip:char

   field=contacts:char:5

   field=last-contacted:date

example

! declare arrays

create-array name=emps size=1           ! one row needed for this example

   field=Salary:number=35000               ! initialize to 35,000

   field=Comm:number=5000                  ! initialize to 5,000

to retrieve value from the array

get #sal #com FROM emps(0) Salary Comm

Multiple report

declare-layout labels

    paper-size=(10,11)   left-margin=0.33

  end-declare

to use the declared report

use-report labels