I have database query similar to below one, it is working fine when i execute this in mySql but it failing in Junit with error "expression not in aggregate or GROUP BY columns:". My JUnit uses in memory HSQL DB. I have gone through the Strange behavior of HSQLDB and group by and understand we need to give group by for all fields when aggregate method is used in the query.
But i have a requirement where i need to get the all the value based on grouping with only one column(which is not primary key), can you please suggest how can i achieve this in JUnit.
Query which I'm executing :
Select *, count(sampleField) from TestTable where sampleField2 != null group by sampleField
You can use min(column_name) or max(column_name) for the other columns.
For example, if you have columns named firstname and lastname
Select min(firstname), min(lastname), count(sampleField) from TestTable where sampleField2 is not null group by sampleField
Edited: use is not null instead of != null for correct results.
Related
I am using a single Spring JDBC update to make an update to two tables in my Postgres database. My SQL query is as follows:
UPDATE accounts SET last_transaction_amount = :transaction_amount WHERE acct_num = :acct_num; INSERT INTO transactions (transaction_amout) VALUES (:transaction_amount);
Using NamedParameterJdbcTemplate#update, I have no issue executing this query and achieving the expected results.
The transactions table generates a sequential transaction identifier, and I want to return this to my application.
I've tried passing a GeneratedKeyHolder in the update call. This is returning the error "A result was returned when none was expected". Docs link.
I've tried passing a GeneratedKeyHolder and array of column names (new String[] {"transaction_id"}). This is returning the error that the column doesn't exist. Note this method call does work to return the transaction id when I only pass the INSERT query without the preceding UPDATE query. Docs link.
How can I retrieve the generated key? Thank you!
You seem to be looking for the RETURNING clause. Assuming that the serial number is called transaction_id:
INSERT INTO transactions (transaction_amout)
VALUES (:transaction_amount)
RETURNING transaction_id;
I have the following JPA query that truncates dates to a full hour and counts them:
SELECT a.alertconfiguration.id.id,
date_trunc('hour', a.date) AS fromDate,
count(*) AS count
FROM alert a
GROUP BY a.alertconfiguration.id.id,
a.alertlevel,
date_trunc('hour', a.date)
I'm running this in a Spring Boot application using Hibernate. It works fine. But I don't want to duplicate the function call to date_trunc.
I have tried referring to fromDate in the GROUP BY clause but then I get an exception org.postgresql.util.PSQLException: ERROR: column "fromdate" does not exist
http://hibernate.atlassian.net/browse/HHH-9301 also states it is not possible to refer to aliases in the group by clause.
How could I rewrite my query without the duplicate function call?
Can you give a try using 2 instead of date_trunc('hour', a.date) in group by clause, as fromdate is 2nd column
Hibernate does not work with alias in group by or any aggregate functions. And as you will see in your sql query generated, the alias is different than that you have assigned.
I am trying to setup a query for my application to pull only values from a table that have a specific column set. Mostly this column will be null, but if you edit and save the item on the application end without putting anything in this field, then it saves a blank string to that database field.
I have tried the TSQL query:
SELECT * from TABLE where COLUMN is not NULL AND COLUMN != ''
This query returns the results I need, but when I run the same query in HQL:
SELECT OBJECT from TABLE where COLUMN is not NULL and COLUMN <> ''
Then it still contains the values that have a blank string in that column. I have tried this using HQL with the operators <> and !=, and have also tried converting it to a criteria object using Restrictions.ne("column","") but nothing seems to provide the result I need.
I tried Length as in the comments, but had no luck. With the length in the query hibernate generates the full query as so. the time_clock_id column is the one that i'm having the problem with. Hibernate is set to SQLServerDialect
select timezone0_.time_zone_id as time1_368_, timezone0_.version as version368_, timezone0_.modification_timestamp as modifica3_368_, timezone0_.time_offset as time4_368_, timezone0_.modification_user as modifica5_368_, timezone0_.name as name368_, timezone0_.description as descript7_368_, timezone0_.active as active368_, timezone0_.time_clock_id as time9_368_ from time_zone timezone0_ where timezone0_.active=1 and (timezone0_.time_clock_id is not null) and len(timezone0_.time_clock_id)>0
Rookie Mistake. There was another place within my action class where I was using a different query to build the select list in the application. This was resulting in the list being overwritten with all values instead of those that use blank. After snipping this duplication I can use the operator column <> '' and I am getting the correct results
I use MySQL 5.5 with Hibernate 3.6 and JPA 2.0. I have a User table with a firstName which could also be null or an empty string. I want to have those empty firstName results last in my search results. For that I wrote the following SQL query which works just fine:
SELECT * FROM User ORDER BY ISNULL(firstName), firstName = "", firstName ASC LIMIT 100
Now want to translate this to JPA using the criteria API and I am not quite so sure about the order by. Here is what I have:
criteriaQuery = criteriaQuery.orderBy(cb.asc(cb.isNull(users.get(User_.firstName))), cb.asc(cb.equal(users.get(User_.firstName), "")), cb.asc(users.get(User_.firstName)));
However, the code snippet above does not work, because the CriteriaBuilder.isNull() method is traslated to IS NULL and not to the ISNULL() function of MySQL. I get the following exception:
org.hibernate.hql.ast.QuerySyntaxException: unexpected AST node: is null
Any ideas on how to check for null in the Order by statement with JPA 2.0
That is not possible. In JPA you can ORDER BY fields only that you select (that are in the SELECT part of your query). The problem is that there is no IS_NULL function, that can be used in the SELECT part.
I got the exact same problem as you do, finally I solve it using this way, maybe you can try:
CriteriaQuery<> query;
query.orderBy(cb.desc(cb.selectCase().
when(cb.isNull("field name"),0).otherwise(1)),
cb.asc("field name");
I am trying to write a DAO using Spring's HibernateTemplate that supports deletion from a table based on several conditions. For example, sample SQL:
Delete from Employee where Name='E01' AND Dept='D01' AND Address='ADR01';
I wrote the below code for this query:
session.createQuery("delete from Employee where name=? and dept=? and address=?")
.setParameter(0, name).setParameter(1, dept).setParameter(2, address)
.executeUpdate();
it works fine if all columns in where clause have some values. However, if I try to delete records which have "NULL" in their any column, then it does not work.
The generated SQL Query is always of the form:
Delete from Employee where Name=? AND Dept=? AND Address=?;
which of course cannot handle NULL comparison - SQL requires "IS NULL" for checking NULL and "=null" doesn't do the trick here. So when I pass dept as null in Java code, the generated SQL would be of the form:
Delete from Employee where Name='E01' AND Dept=null AND Address='ADR01';
This does not delete the records from DB which have NULL values in Dept column, as the correct condition would be "Dept IS NULL"; and "Dept=null" does not work! Is there anyway to compare NULL values in where clause without using a native query?
NOTE:
I do not want to use deleteAll(Collection) method of HibernateTemplate, as it requires fetching the records first and then deleting them - i.e. more than 1 SQL query. I want to achieve deletion using a single SQL query, without requiring to select first, or requiring native queries.
I am aware that Spring advices using SessionFactory now, but I am stuck with HibernateTemplate in existing code base.