I get no php warning, but the same things happens on 6.2.16 and 8.0 (latest dev); also it does not depend on having selected "CVS Export";

What happens is that every time you update the query, some "weird" and unwanted where statement gets appended, and it does not happen every time, but only with some tables

I tried the following step:

1) DB Check > advanced query > select table: page
2) the default query is: select fields: uid,title that becomes:

SELECT uid,title,pid,deleted FROM pages WHERE (
pages.doktype LIKE '%%') AND pages.deleted=0 LIMIT 100

and that's ok.

3) now try to add at least one field e.g. "navigation title": when you click some "reload" button, the part "Make Query:" changes from "Type":"equals":"page" to "Type":"equals":"special" and the query becomes:

SELECT uid,title,nav_title,pid,deleted FROM pages WHERE (
pages.doktype = '--div--') AND pages.deleted=0 LIMIT 100

when you try to modify by hand "Type":"equals":"special" into "Type":"equals":"page", that does not work and the reloads always reload "Type":"equals":"special". Selecting "Type":"equals":"standard" works.

Something similar happens with tt_content table, but not for example with be_users.

When you try to run the query with a plugin (I tried with the news plugin), the behavior is a bit more weird:

The initial (working) query is:

SELECT uid,title,pid,deleted FROM tx_news_domain_model_news WHERE (
tx_news_domain_model_news.sys_language_uid LIKE '%%') AND tx_news_domain_model_news.deleted=0 LIMIT 100

After selecting an additional field (e.g. teaser) and clicking on a reload button:

SELECT uid,title,teaser,pid,deleted FROM tx_news_domain_model_news WHERE (
tx_news_domain_model_news.sys_language_uid = '-1') AND tx_news_domain_model_news.deleted=0 LIMIT 100

so, again, it changes the WHERE sys_language_uid part. Funny thing is that in both cases the interface "Make Query:" shows: "language":"equals":"[all]" .

I guess it has been solved in the meanwhile: I repeated my test on comment 2 on 9.5.15 and these are the results:

Test 1: pages table¶

1) DB Check > advanced query > select table: page
2) the default query is: "select fields:" "uid,title" and automatically adds "Type" "equals" "Standard"

the final query shown is:

SELECT `uid`, `title`, `pid`, `deleted` FROM `pages` WHERE (pages.doktype LIKE '%%') AND (`pages`.`deleted` = 0) LIMIT 100

3) now try to add at least one field e.g. "navigation title": when you click some "reload" button, the part "Make Query:" still has "Type":"equals":"Standard" but now it is part of the query

Thus the query becomes:

SELECT `uid`, `title`, `nav_title`, `pid`, `deleted` FROM `pages` WHERE (pages.doktype = '1') AND (`pages`.`deleted` = 0) LIMIT 100

Test 2: be_users table

1) DB Check > advanced query > select table: Backend user
2) the default query is: "select fields:" "uid,title" and automatically adds "Username" "contains" ""

The query shown is:

SELECT `uid`, `username`, `pid`, `deleted` FROM `be_users` WHERE (be_users.username LIKE '%%') AND (`be_users`.`deleted` = 0) LIMIT 100

3) now try to add at least one field e.g. "email": when you click some "reload" button, the part "Make Query:" still has "Username":"contains":"" and the final query becomes (I omit the screenshot):

SELECT `uid`, `username`, `email`, `pid`, `deleted` FROM `be_users` WHERE (be_users.username LIKE '%%') AND (`be_users`.`deleted` = 0) LIMIT 100

Test 3: tx_news_domain_model_news table¶

1) DB Check > advanced query > select table: News
2) the default query is: "select fields:" "uid,title" and automatically adds "Language" "contains" "" and the query becomes (I omit the screenshot):

SELECT `uid`, `title`, `pid`, `deleted` FROM `tx_news_domain_model_news` WHERE (tx_news_domain_model_news.sys_language_uid LIKE '%%') AND (`tx_news_domain_model_news`.`deleted` = 0) LIMIT 100

3) now try to add at least one field e.g. "teaser": when you click some "reload" button, the part "Make Query:" still has "Language":"contains":"" and the final query becomes (I omit the screenshot):

SELECT `uid`, `title`, `teaser`, `pid`, `deleted` FROM `tx_news_domain_model_news` WHERE (tx_news_domain_model_news.sys_language_uid LIKE '%%') AND (`tx_news_domain_model_news`.`deleted` = 0) LIMIT 100

Is this the expected behavior? Is a different test necessary?

seems to be resolved as Richardo mentioned. If not, please open a new issue with steps how to reproduce it.