Category: Macros

Macros

Quickie: How to use the new macro function queryValue

| cognospaul

A very pleasant surprise when building reports. There’s a new function called “queryValue”.

On the surface it looks fairly innocuous, but the result of this is a lot of effort saved when building reports. There are many times where I want a way of pulling a default value from a database in a filter. For example, my report might need to let the user select a year, but last date with data is unknown. Normally we can do something like:

[Sales (query)].[Time].[Year] = #prompt('Year','integer',
'maximum([Sales (query)].[Time].[Year] for report)'
)#

WITH 
"TQ0_q_SelectedMonth1" AS 
    (
    SELECT
        "GO_TIME_DIM"."CURRENT_YEAR" AS "Year0", 
        MAX("GO_TIME_DIM"."CURRENT_YEAR")
            OVER(
            ) AS "Max1"
    FROM
        "GOSALESDW"."gosalesdw"."GO_TIME_DIM" "GO_TIME_DIM"
    )
SELECT
    "TQ0_q_SelectedMonth1"."Year0" AS "Year0"
FROM
    "TQ0_q_SelectedMonth1" 
WHERE 
    "TQ0_q_SelectedMonth1"."Year0" = "TQ0_q_SelectedMonth1"."Max1" 
GROUP BY 
    "TQ0_q_SelectedMonth1"."Year0"

It works, but I don’t like it. It’s creating a window function, and actually hits every row in that table. One way around would be to create a parameter map in the framework model. Create a model query that has the value you want, add a data item with a static 1, and create a parameter map based on that. You could then do:
[Sales (query)].[Time].[Year] = #prompt('Year','integer',
sq($lastYearWithData{1})
)#

Then the SQL will look like: 

SELECT
    "GO_TIME_DIM"."CURRENT_YEAR" AS "Year0"
FROM
    "GOSALESDW"."gosalesdw"."GO_TIME_DIM" "GO_TIME_DIM" 
WHERE 
    "GO_TIME_DIM"."CURRENT_YEAR" = 2013 
GROUP BY 
    "GO_TIME_DIM"."CURRENT_YEAR"

This is much better but still way too clunky. It requires access to the framework model, and a new parameter map for each and every scenario that we need. What if we want the last date of data for a specific product line? Or product?

Instead, let’s take a look at queryValue()

[Fact Business].[Dates].[Year] = #prompt('Year','integer'
, queryValue('maximum([Sales (query)].[Time].[Year])')
)#

This behaves exactly like the parameter map, and the SQL is identical. Cognos is actually making a query that runs maximum([Year]), and returns that value to the macro – exactly like a parameter map would. We can add filters to the query like this:
[Sales (query)].[Time].[Year] = #prompt('Year','integer',
queryValue('maximum([Sales (query)].[Time].[Year])','[Sales (query)].[Sales].[Quantity]>0 and [Sales (query)].[Products].[Product]=''Trail Star''')
)#

Notice using a double quote to escape the single quote. Great Outdoors stopped selling Trail Star in 2011, and 2011 is now the default value in the prompt.

This is also especially useful in Data Sets and Data Modules, where parameter maps simply don’t exist.

8.4, Macros

Token prompts

| cognospaul

Token prompts are an extremely powerful macro. They allow authors to create extremely efficient code that would otherwise be difficult or impossible to make.

The following examples will all be based on the Great Outdoor Sales (cube) package.

A simple example would be a static prompt that would allow the user to see a list the top or bottom products by revenue. Without a token prompt you might be tempted to use the following expression:

case #prompt('TopOrBottom','string',sq('top'))#
when 'top' then topCount([great_outdoor_sales_en].[Products].[Products].[Product],5,[great_outdoor_sales_en].[Measures].[Revenue])
when 'bottom' then bottomCount([great_outdoor_sales_en].[Products].[Products].[Product],5,[great_outdoor_sales_en].[Measures].[Revenue])
end

The problem with that is that it simply doesn’t work. You could also try to make a conditional block, but that would make the report needlessly complex.

Instead you could use a token prompt:
#prompt('TopOrBottom','token','top')#Count([great_outdoor_sales_en].[Products].[Products].[Product],5,[great_outdoor_sales_en].[Measures].[Revenue])

When the macro resolves the function will be either topCount or bottomCount.

Macros, Prompts

Macros (3 of n++): Prompts

| cognospaul

Macros allow you to alter SQL/MDX before it’s send to the datasource. Using the macro functions timestampmask, you can easily select specific members, or query certain tables.

Prompt macros give you an extremely fine grain of control. You can, for instance, allow a user to which measure he wants to see in his graph, or create dynamic default values.

To begin with, the structure of the prompt macro:

#prompt/promptmany(‘parameterName’,’dataType’,’defaultValue’,’leadingText’,’source’,’trailingText’)#

parameterName is self explanatory. Note that it is case sensitive. If you want to pass a value to that parameter via the URL or POST you need to preface it with a p_ so Par_Year becomes p_Par_Year.

The dataType will reject anything not covered by the datatype. The string ‘Hello World!’ would be rejected if the datatype was set to integer. The datatype also determines the type of prompt generated. ‘Integer’, for example, will always create a text box prompt even if the source field (see below) is filled.

The defaultValue will be returned if no parameter is selected. This does not need to obey the dataType. For example, you could have a filter set up: [Year] = #prompt(‘parYear’,’integer’,’year(getDate())’)# If 2010 was selected the filter would be [Year] = 2010, if no value was returned to the prompt the filter would be [Year] = year(getDate()).

The leadingText is text that is automatically entered before the selected parameter. For example a filter: #prompt(‘parYear’,’integer’,’1=1′,'[Year] = ‘)# In that example if 2010 was selected [Year] = 2010 would be returned to the filter. If nothing was selected, the filter would be 1=1.

The source will a list or tree prompt based on a referenced field. #prompt(‘timeMember’,’memberuniquename’,”,”,'[NS].[TimeDimension].[TimeHierarchy]’)# will create a tree prompt that will allow the user to select any member from the TimeHierarchy. #prompt(‘timeMember’,’memberuniquename’,”,”,'[NS].[TimeDimension].[TimeHierarchy].[MonthLevel]’)# will create a list prompt that will allow the user to select a single member from the MonthLevel. You can also include functions in the source: #prompt(‘timeMember’,’memberuniquename’,”,”,’filter([NS].[TimeDimension].[TimeHierarchy].[MonthLevel],[Measures].[Sales]>1000)’)# will create a list prompt of all months that had more than 1000 sales.

The trailingText, much like the leadingText, placing text after any values selected. #promptmany(‘Years’,’memberuniquename’,’children([NS].[TimeDimension].[TimeHierarchy]->[All Member])’,’set(‘,'[NS].[TimeDimension].[TimeHierarchy].[YearLevel]’,’)’)# will either return the children of the All member (if no values are selected), or will return a set of members that the user selected.