"Error:null" when clicking the "Read Fields" button in the Query Editor

Sometimes the "Error:null" error  appears after clicking the "Read Fields" button in the Query Editor or after autorefresh. One of the causes for this can be usage of literal parameters like $P!{param} in the query which the editor cannot calculate at the time. Just delete the parameter temporarily and restore it after "read fields" completes.

How to detect if Jasper Reports output was generated by a scheduled run

Sometimes it is necessary to have some conditional logic in case a report is being run by a scheduler. In this case it is possible to use _ScheduledTime parameter from the built-in REPORT_PARAMETERS_MAP map.

Example expression:

$P{REPORT_PARAMETERS_MAP}.get("_ScheduledTime") == null ? "Normal" : "Scheduled"

Concatenate full name in reverse order with comma and optional title

Sometimes it is preferrable to output full name as a single field/column like
<last_name>, <title> <first_name>
where title and first name are both optional (as occurs in the real world). Because of the different combinations where title and/or first name are null there should be some conditional logic with concatenation. But you can do correct concatenation in a single expression using the fact that coalesce(right(title,0),', ') will return empty string when title is not null and  separator', ' otherwise:

select 
trim(
upper(family_name) || coalesce(', ' || title || ' ', '') || coalesce(coalesce(right(title,0),', ') || given_names, '')
) as person_name 
from person

Move cursor to specific text in Word VBA

Sometimes it's necessary to replace placeholders (e.g. <content_placeholder1>) in a Word document with some generated or imported content using VBA macro. Just replacing the placeholder text via Selection.Find.Execute Replace:=wdReplaceAll  will not move a cursor, you need to do it as a separate step like below:

Sub moveToPlaceholder(tableName As String)

    Dim placeholderText As String

    placeholderText = "<" & tableName & ">"
    
    ' first find
    With Selection.Find
      .Text = placeholderText
      .Forward = True
      .Wrap = wdFindContinue
      .Format = False
      .MatchCase = False
      .MatchWholeWord = False
      .MatchWildcards = False
      .Execute
    End With
    
    ' now move cursor at the
    Selection.EndKey Unit:=wdLine
    
    ' now replace
    With Selection.Find
      .Text = placeholderText
      .Replacement.Text = ""
      .Forward = True
      .Wrap = wdFindContinue
      .Format = False
      .MatchCase = False
      .MatchWholeWord = False
      .MatchWildcards = False
      .Execute Replace:=wdReplaceAll
    End With
  
End Sub

ERROR: character with byte sequence <...> in encoding "UTF8" has no equivalent in encoding "WIN1252";

I've encountered this error "ERROR: character with byte sequence <...> in encoding "UTF8" has no equivalent in encoding "WIN1252";" while using MySQL Workbench to migrate data from PostgreSQL to MySQL. I was not sure why this was happening because the target MySQL database had UTF8 encoding and I thought that everything can be mapped to it.

The real root cause of this problem turned out to be the PostgreSQL driver I used to connect to the source DB and specified in the Workbench which was PostgreSQL ODBC Driver (ANSI) and after I changed it to PostgreSQL ODBC Driver (UNICODE) everything worked fine.

How to view .oxps (Open XPS) files on Windows 7

I didn't expect this simple thing to be so tricky, mostly because the utility name is not XpsConverter.exe but OxpsConverter.exe instead.  So here's a solution for you for when you cannot find an XpsConverter.exe:

In order to convert and view .oxps files on Windows 7 you need to use OxpsConverter.exe which should be located in C:\Windows\System32 folder, just try to run C:\Windows\System32\OxpsConverter.exe from command line.

If you don't have it, download and install a Windows update for you version from here:
http://support.microsoft.com/kb/2732059

Using the converter is very simple, just run
C:\Windows\System32\OxpsConverter.exe "file_to_convert.oxps"
and it will open a small GUI asking you where to convert the file to .xps format which can be opened by default in Windows 7.

NOTE: If you don't have then try looking for XpsConverter.exe
in %programfiles%\Windows Kits\8.0\bin\ or %programfiles(86)%\Windows Kits\8.0\bin\
if you happen to have Windows Driver Kit 8 (WDK) installed.

org.postgresql.util.PSQLException: ERROR: could not determine data type of parameter

I was getting this error from Jasper server when leaving datetime input control blank:

Error Message

org.postgresql.util.PSQLException: ERROR: could not determine data type of parameter $3

Error Trace

org.postgresql.util.PSQLException: ERROR: could not determine data type of parameter $3 at org.postgresql.core.v3.QueryExecutorImpl.receiveErrorResponse(QueryExecutorImpl.java:2102) at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:1835) at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:257) at 

Where clause in the query for java.sql.Timestamp column was like this:

and (time_col > $P{inputStartCreatedDate} or $P{inputStartCreatedDate} is null)

The solution is to add explicit type conversion like this:

and (time_col > $P{inputStartCreatedDate} or $P{inputStartCreatedDate}::timestamp is null)