You experience that when you execute a query it is not written to HISTORY. The query itself executes correctly.
The reason is that your query is too big to be logged to HISTORY. Queries exceeding 4 KB in size are not logged. The reason is that HISTORY is kept in memory. And to avoid memory use 'build up' this limit was introduced with a previous SQLyog version.
The 4 KB limit is not configurable.
Statements can be MB's, GB's in size so it has been necessary to introduce this limit. For instance a single LONGTEXT or LONGBLOB variable can be as big as 4 GB.
I am experiencing a similar problem on a very short but very slow query, not written to history... I know it is coming from SQLyog because the user and IP can only match this program. So... even on a large query why not write a placeholder to history? "Query executed: too long to show"
Added at: 2012-10-13 18:54
@Rob .. Please do not use our FAQ to ask support. Support is available from our Forums at http://www.webyog.com/forums and from support@webyog.com. The option to comment here should only be used if you have comments that will help other people. To ask help for yourself please use the above-mentioned support options. -- Peter -- Webyog
Added at: 2012-10-14 13:13