API/Queries/Saved-Queries.md

+The entity extensions.query is used to save queries. It takes the same arguments "attrs" and "conds" as [[General Queries]]. It is a normal entity, so all endpoints work as usual. The only difference is that the [[General Queries]] endpoint knows it is the entity where saved queries are stored.
+
+To save a query, call 
+
+`/data/extensions/query/transitions/create`
+
+```JSON
+ {                       
+    "entity": "98",
+    "name": "employee filter",
+    "conds": {"date_of_birth": {"<":"1994-03-28"}},
+    "atts": {},
+    "is_default": "FALSE",
+ }
+```
+
+this will return the query id which can then be used on the entity.
+
+If `is_default` is set, it will be set as the new default search for the entity.
+
+### Calling a query
+
+`/data/$module/$entity/query?id=$id`
+
+In addition to the id, the general paging parameters (limit, offset, page, page_size, no_filtered_count) can be used.
+
+It is also possible to overload the search `conds` and the `order_by` flag, `attrs` will be ignored. 
+
+```
+/data/$module/$entity/query?id=$id&conds={"id":"3"}      -> works, returns entry with id=3
+/data/$module/$entity/query?id=$id&order_by=$column      -> works, returns list in that order
+/data/$module/$entity/query?id=$id&attrs={"bla":"blubb"} -> does not work, attrs are ignored
+```
+
+### Invalid queries
+
+A query can become invalid if the underlying database model changes. It will be flagged as invalid once it's been used and produced an error. A subsequent database model change sets all queries with is_valid=FALSE to is_valid=NULL and the query will be tested when it's next used. After that, it's is_valid flag is set again.
+
+* is_valid=TRUE  -> worked last time it was used
+* is_valid=FALSE -> failed last time it was used 
+* is_valid=NULL  -> state unknown after model change
+
+### Caching
+
+All queries are cached by the api, and get updated when there is a change. To rebuild the cache (at system startup or when there is a problem), execute:
+
+    script/cache_update.pl --no-create-schema-files --no-dump-errors
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