Archive for the 'Method' Category



Fun with looping logic

Wednesday 17 June 2020 @ 11:59 pm

I had a fun challenge today. A customer had a table with an odd structure. One column was a payment amount. It was followed by 40 different columns for various fees. He wanted the payment amount to be applied to the fees from smallest amount to largest amount until the payment was used up. The report was to show the balance for each fee after the payment was applied.

Normally this type of data would be vertical. There would be a separate row for each fee and only 2 columns (fee name and the fee amount). With that structure you could sort by fee amount and use a variables to apply the payment to the records in ascending order. But with 40 fixed columns I had to load the values into an array, and then put the values in the right order.

I loaded the fees into the array as strings, combining the amounts and fee names into one element looked this:

24.50=xyzFee

This allowed the fee name to follow the amount through the sorting process.

Once I loaded all these strings into the array I used my bubble sort formula to re-sort the array from lowest amount to highest amount. In the bubble sort comparison I used the Val() function to convert the strings to numbers. This put them in order by their true numeric value.

Then I wrote a second loop to apply the payment. It steps through the array, which is now in the right order, and applies the payment to the fees, one at a time. Each fee amount is reduced to zero while the payment value is reduced by the amount of each fee.  If  the payment’s remaining value drops below the amount of the next fee the remainder is subtracted from that fee and the payment is reduced to zero. Any fee amounts in the array beyond that point stay the same.

Last, to display the results, I wrote 40 separate formulas, one for each fee. Each of these formulas loops through the array looking for its specific fee description. When it finds the element with a matching description it uses the Val() function to convert that string to a numeric value and displays that value.  This is the relatively simple loop formula:

EvaluateAfter({@Build Fees Array});
stringVar Array Fees;
Local numberVar i;
Local numberVar fee;
FOR i:=1 to ubound(Fees)
DO (
if 'xyzFee' in Fees[i]
then Fee := val(Fees[i])
);
Fee

Not many people would think this process was fun, but I did enjoy mapping out a creative approach to a unique requirement. And it was less than 2 hours from the requirements to a validated report. The next time your report requirements are a bit unorthodox, keep  me in mind.




Giving the database what it needs

Monday 8 June 2020 @ 8:35 pm

Today a user asked me how to automatically select the prior month’s transactions from the database. The transactions didn’t have dates, but instead had two numeric fields for Period (month) and Year. They were using a formula to convert these two numbers into a date and then using that formula as part of the selection formula. That approach will work but it is usually slow. This is because the database (or the SQL Query) doesn’t know anything about the date formula in the report, so it can’t apply any date criteria before sending back the data.  Crystal gets all years and periods and then has to apply the criteria in the report.

A more efficient approach is to start at the other end. Instead of converting the DB fields to match the criteria values, we convert the criteria values to match the the database fields and let the database do the heavy lifting. In this case created three formulas:

// Prior Pd End Date
Maximum (LastFullMonth)

This gives us the last date of the prior month. From there I created two formulas that extract the year and the month from that date:

// Prior Pd Month
Month ({@Prior Pd End Date})

// Prior Pd Year
Year ({@Prior Pd End Date})

Then the selection formula can use these values to filter the DB fields, something like this:

….
and {Trans.Year} = {@Prior Pd Year}
and {Trans.Period} = {@Prior Pd Month}

This should allow the criteria to be passed to the WHERE clause of the SQL, and maybe even hit an index to make short work of finding the correct records.

The principle works the same if you are using a Date Range parameter.  You could use formulas to convert the parameter values so they match the database fields.  I wrote about this a few years ago in a similar case where the dates were stored as strings.




Highlighting a phrase within a larger field

Wednesday 27 May 2020 @ 1:58 pm

One of my readers shared a solution he recently found for highlighting a specific string within a larger field (like a comment, notes or memo field). To provide an example, I wrote a report against the Xtreme database and highlighted the word “graduate” the first time it occurs in the employee notes field.

There are two parts to his approach. First you write 3 formulas that split the memo field into three separate pieces: the target string, everything before it, and everything after it. Then you reassemble these three pieces by dropping them into a single text object. The target string formula can then be formatted separately so that it stands out within the text.

I used 3 additional formulas to make the process more generic. Here are the formulas I used:

//Target String - replace with your own target
"graduate"

//Target Start - replace Notes field with your Notes field
Instr ({Employee.Notes}, {@Target String})

//Target End
if {@Target Start} = 0
then 1
else {@Target Start} + Length ({@Target String}) -1

//Output Before- replace Notes field with your Notes field
if {@Target Start} <= 1
then ""
else {Employee.Notes} [1 to {@Target Start}-1]

//Output Target - replace Notes field with your Notes field
if {@Target Start} = 0
then ""
else {Employee.Notes} [{@Target Start} to {@Target End}]

//Output After - replace Notes field with your Notes field
{Employee.Notes} [{@Target End}+1 to -1]

The 3 “Output” formulas are dropped into the text object. Make sure the text object is set to “Can Grow”.

The process can be made more sophisticated if the target string varies in length, as long as you can clearly identify the character pattern that marks the beginning and the end of the target string. If you need help with that let me know and we can schedule a short session.

There is also an alternate approach where you embed HTML tags before and after the target string and then use Crystal’s HTML interpretation to change the format at runtime. However, this is limited to the HTML tags that Crystal supports.

Finally, thanks to Doug Weiner at Beacon Legal Software Services for suggesting this post.




Repeating the first columns of a cross-tab for each value in the second column

Friday 8 May 2020 @ 11:44 pm

This is better illustrated with pictures. Recently a customer had a Cross-tab that looked like the image on the left below. But they wanted the first column to repeat next to each value in the second column, like the image on the right below.

cross-tab without repeating the first column

I found a relatively simple way to do this:

  1. I created a formula the combined the two column fields into one string, with a dash between them.
  2. I went into the Cross-tab expert and clicked the “Group Options” button for the first column field. I changed it to the new formula.
  3. I then clicked the”Options” tab and checked the option “Customize Group Name Field”.
  4. I used the drop down to select the database field that was the original field used for the first column, then clicked OK.
  5. I went to the the last tab in the Cross-tab expert named “Customize Style” and highlighted the concatenated formula in the “Rows” box.
  6. I checked the option “Suppress Subtotal” (if not already checked) and clicked OK.

The cross-tab then looked like the one on the right.




Reading an Excel column as a true DateTime rather than a string.

Wednesday 29 April 2020 @ 10:43 pm

I have written before about data type changes in Excel. One article explained how to convert a column of numbers into character values so that they can link correctly to another column of character values.

Today I was asked how to do something similar with dates. Two spreadsheets were being linked on a date field, and Crystal was reading one field as a true date and one as a string date. I found a simple way to get Crystal to recognize the string as a date. I created another column that was simply the Date String column plus zero [e.g. =A3 + 0].  This turned the new column into a number representing the date. Then I formatted that column as dates and that allowed Crystal to recognize the new column as a date.

It surprised me to find that I had to format the field as a date. When it comes to dealing with strings and numbers the formatting is usually irrelevant, but apparently with dates the format is important. When I tried to skip formatting the column as a date, Crystal read the new column as numeric values.




Cross-tabs can total formulas that you can’t normally total

Tuesday 10 March 2020 @ 1:44 pm

One of my first 10 blog posts explained why some formulas could be totaled and others could not. Two of the things that prevent a formula from being summarized (totaled) are if the formula itself refers to a subtotal, or if it uses the functions Previous() or Next().

But I was reminded recently that both of these types of formulas can be summarized in a Cross-tab. Take these two formula examples:

// Rebate:
if Sum ({Orders.Order Amount}, {Customer.Customer Name}) > 25000
then {Orders.Order Amount} *.05
else 0

//Days Between Orders:
if {Customer.Customer Name} = Previous({Customer.Customer Name})
then {Orders.Order Date} - Previous ({Orders.Order Date})
else val({@null})

If I wanted to do a grand total of my rebates or an average of the days between orders I wouldn’t be able to use normal summary functions.   Even Crystal running total fields won’t work with these. In most cases people would resort to using variable to accumulate these totals. However, both of these formulas can be summarized using a cross-tab. You could do a simple cross-tab with a single cell to show the grand total and no row or column fields.  Or you could do breakdowns by other fields.

Not only does this save you dealing with variables, but a cross-tab can put these totals on the first page (Report Header), while variables will only be complete on the last page (Report Footer).  One more reason to use my favorite objects.




Charting based on a parameter value

Saturday 29 February 2020 @ 10:51 am

I have had several customers over the years who wanted to add a fixed line to a bar/line chart. This is typically some type of target or standard that they want to compare the actual data. If this value is in the report’s query results, then it is pretty straightforward. But what if the user wants to be prompted to enter the value to be used in the chart? Crystal won’t let you add the parameter directly to the chart. Even if you put the parameter value in a formula, Crystal might not allow that formula in the chart.

The reason is that parameters come before the data is read. This means that they are evaluated “BeforeReadingRecords” by default. Values that come before the data is being read are not eligible for grouping, sorting, totaling or charting. But if you put the parameter in a formula you can change the evaluation time of the formula to “WhileReadingRecords”. This will make it into a column of values. And even though they are all the same, they will be available in the chart expert as a value to be summarized. Something like this:

WhileReadingRecords;
{?YourParameter}

Then in your chart you can either summarize it by using a Maximum, or checking the “Do Not Summarize” check mark.

If you need to do this and have trouble then call me to schedule a short consult, or Email me your report and explain your requirement.




Using the ‘parent’ section in the Section Expert

Sunday 23 February 2020 @ 7:24 pm

If you have ever done a page break or a suppress condition in Crystal Reports, you have been in the Section Expert. This is where you can change any of the formatting properties of the sections. And if you have ever split a section into subsections, you know that each subsectioin has their own set of properties in the Section Expert.

But users don’t always notice that whenever you split a section into subsections, the parent section still exists in the Section Expert. So when you split the Details section in to Details A and Details B, there is still an item called Details in the list of sections, and this ‘parent’ section has properties that apply to all of the subsections at once. For example:

  1. If you check “Keep Together” in the parent section Crystal will try to keep all the subsections together on a page, and if they won’t fit will move them ALL to a new page.
  2. If you put a suppress condition in the parent section it will suppress ALL of the subsections at once.
  3. If you check “New Page After” in the parent section it will generate a page break after the last detail subsection, even if you rearrange the details.

You might find that this helps simplify formatting sections with subsections.




“New Page After” on group 2 orphans group footer 1

Tuesday 18 February 2020 @ 8:24 am

If you have two group levels and you put a “New Page After” on Group Footer 2, you will find that Group Footer 1 gets orphaned onto it’s own page. To fix this put a “New Page After” on Group Footer 1. Then instead of putting the same check mark into Group Footer 2 you use the following condition on the “New Page After” property:

{Group1.DatabaseField} = Next ({Group1.DatabaseField})

Of course you use your own database field from Group 1 in the formula. This prevents Group 2 from doing a page break on the last record of the group. On that record the next value for Group 1 is different, so the page break is handled by Group 1.




Column breaks in a multi-column report

Monday 30 December 2019 @ 11:12 pm

Crystal allows you to have multiple columns on a page. This is handy when you have a narrow list or a label and you want to pack more data on each page. To set up multiple columns you go to the section expert, highlight the ‘details’ section and check the option to ‘format groups with multiple columns’. This exposes a tab on the right that is labeled “Layout”. Here you can set the width of the column, the space between columns, and if the columns should go across then down (filling the top of the page first) or go down then across (filling the left side first).

Here you can also determine if the group headers and footers are part of the columns or if they go across the entire page and are separate. Usually, you want the groups to be included when you are using “down then across” and not when you are using “across then down”.

If you are using “down then across” and your groups are part of the columns you might want to have each group start in a new column. Crystal has a specific feature when you want a page break after a group, but not when you want a column break after a group. My workaround is to create a very thin group footer and then set it to “print at bottom of page”. This will force the next group to be at the top of a column.

Since long groups might start on one page and continue on the next, you should probably also set the group option to “repeat group header on each page”. This way the group spilling on to the next page has a label to identify the group.

This method isn’t perfect. You might occasionally get an empty column if the records fill the column exactly. Or you might want to line up the top of each group’s second column with the top of its first column, or maybe even repeat the headings with each column. For help with these issues see Expert Techniques Volume 2.




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Jeff-Net

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