About max
GROUP BY and HAVING clauses
Explains how to use the GROUP BY and HAVING clauses in a JPA/JPQL query.... Aggregate calculations (count, sum, avg, max, min) that are carried out on all the objects (or the object tuples) in the ... values (numeric, strings, dates). MAX - returns the maximum of comparable values (numeric, strings, dates). ...
max(x)
Create an aggregate expression applying the numerical max operation.(Method of javax.persistence.criteria.CriteriaBuilder)
Server Configuration
Explains how to set a JPA/JDO database server using ObjectDB, the fast Java object database for JPA/JDO.... > <connection port = "6136" max = "100" /> <data path = "$objectdb/db-files" ... element <connection port = "6136" max = "100" /> The <connection> element specifies ...
Error using query with MAX() function
I have a class that is persisting a Entity that holds remarks and a time. Then when I query for the latest remark I get a internal error when the remark is larger than 1966 chars. Here is a test class and entity that reproduces the problem on my system. ... ) ; Expression me = cb. max ( c ) ; CriteriaQuery<Object> s = q. ... #150 query.manager] <queryRequest query="SELECT MAX($1.addDate) FROM Notes $1 WHERE $1.addDate IS NOT NULL" args="null" ...
JPA Query Structure (JPQL / Criteria)
Explains the structure of a JPQL query, which consists of 6 clauses: SELECT, FROM, WHERE, GROUP BY, HAVING, ORDER BY.... operation. See JavaDoc Reference Page... , max max(x) CriteriaBuilder's method Create an aggregate expression ...
JPA Criteria API Queries
Explains how to use the JPA Criteria API (CriteriaBuilder, CriteriaQuery, etc.) to build JPQL like queries.... operation. See JavaDoc Reference Page... , max max(x) CriteriaBuilder's method Create an aggregate expression ...
em.flush(); em.clear(); loosing data and not persisting managed objects
I'm having trouble with flush() and clear() in a loop inside a transaction not persisting modified objects to database. Sometimes it does other times it doesn't. Here is my Entity. ... for ( int i = 0 ; i<Integer. MAX_VALUE ; i ++ ) { TestEntity v = new ... #132 query.manager] <queryRequest query="SELECT MAX($1.addDate) FROM Notes $1 WHERE $1.addDate IS NOT NULL" args="null" ...
Comparison in JPQL and Criteria API
Explains how comparison operators can be used in JPQL queries, including in comparing null values.... two following expressions are equivalent ( :min and :max are query parameters ): x BETWEEN :min AND :max x >= :min AND x <= :max Similarly, NOT ...
javax.persistence.criteria.CriteriaBuilder
Used to construct criteria queries, compound selections, expressions, predicates, orderings.(Interface of JPA)
Occasionally slow requests in load testing
We are running load testing against objectdb version 2.3.7_18. The performance is generally OK, however there are quite a few "spikes" in the performance where we are getting a lot of very slow response times from the DB, around 10 - 15 seconds. Looking at the DB server process with AppDynamics we can see that most of the requests get stuck in one of 2 places: com.objectdb.o.PGC:w: line number 232 com.objectdb.o.LFL:U: line number 1068 Please see the attached callgraph examples for full stack trace examples. ... /> <log path = "$objectdb/log/" max = "8mb" stdout = "false" stderr = "false" /> ... = "true" sync = "false" path = "." max = "128mb" /> <recording enabled = "false" sync ...
