Expression evaluation error at function a!queryEntity [line 21]: An error occurred while retrieving the data.

Question

Hi All, 
 
 Getting this error in UAT i am able to retrieve data from that view in Dev successfully , I am trying to check logs for this i need to check jboss1-stdOut.log. right ? 
 I am not able to see this logs , Am i checking the correct logs ? if its wrong which to check please let me 
 
 Thanks, 
 Bhargavi

bhargavip0001 · Accepted Answer

Hi All, Writing my approach and solution I got, so that it might be helpful to others if they faced the same issue. Thank you for all your responses when i got this issue i check for the below things. 1)Checked for the columns types of data type and view for any miss-match (everything is fine). 2)Checked for date fields data , it don't have any invalid data(i.e 0000-00-00 or past date(like 200 years ago which appian won't support)) 3)Don't have huge data in the view(so no time out issue) . 4)No duplicate data for the primary key in the view. everything was fine then checked for logs and found the following error. "Caused by: java.sql.SQLException: Illegal mix of collations (utf8mb4_unicode_ci,COERCIBLE) and (utf8mb4_general_ci,COERCIBLE) for operation '=' " This is because collation of the column is changing to utf8mb4_unicode_ci when i create a column with combination and concat of two columns(ex: row_id(10) and row_num(3) so my id will be "10-3" ). Below Article give you the clear information for the changes required. community.appian.com/.../kb-1770-java-sql-sqlexception-illegal-mix-of-collations-for-operation-operator_5f00_name-causes-error-while-loading-records-and-tasks We raised Appian support ticket to do those changes. Thanks, Bhargavi P

bhargavip0001 · Answer

HI yogeshp , My column in view is combination of two columns and appended with '-' ex : "1-2" something like this, even my two columns collation is utf8_general_ci only , My DB is cloud , and when i check the logs error is this 
 
when i checked my logs the error was Caused by: java.sql.SQLException: Illegal mix of collations (utf8mb4_unicode_ci,COERCIBLE) and (utf8mb4_general_ci,COERCIBLE) for operation '=' 
 
and i found this link on forum about this issue is there in 18.1, 18.2 and 18.3 
 
 community.appian.com/.../kb-1770-java-sql-sqlexception-illegal-mix-of-collations-for-operation-operator_5f00_name-causes-error-while-loading-records-and-tasks

Yogesh Pavuluru · Answer

Hi bhargavip0001 , Can you please check the collation of that field in the view? Try to change collation of that table to utf_general_ci. This could be one of the reasons for this error.