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How to Get record from aerospike using list in java?

My data at test.setName looks like this
| id | cities | lob |
|-------|---------------------|------------|
| id123 | ["Cthdcn","Ctdel"] | ["Lob132"] |
| id345 | ["Ctijs","Ctdelhi"] | ["LOB231"] |
| id765 | ["Cthui"] | ["Lob875"] |
"cities" is already present as LIST INDEX, and want to get a
particular record by specifying cities array like(["Ctijs","Ctdelhi"])
via java client.
I want to retrieve (get) records by specifying cities array using
java. I am using the following method
public Record testGet(String namespace, String set, String city, List<String> binNames) {
Statement statement = new Statement();
statement.setNamespace(namespace);
statement.setSetName(set);
Filter filter = Filter.contains("cities", IndexCollectionType.LIST, city);
statement.setFilter(filter);
RecordSet records = this.client.query((QueryPolicy)null, statement);
return records.getRecord();
}
I am getting null. How can I retrieve that specific record? (AQL version 3.23.0)

Here is small script in AQL in a text file, list.aql , to replicate your test:
list.aql:
TRUNCATE test
DROP INDEX test.setName idx_city
SELECT * FROM test
CREATE LIST INDEX idx_city ON test.setName (cities) STRING
INSERT INTO test.setName (PK, id, cities, lob) VALUES ('key1', 'id123', LIST('["Cthdcn", "Ctdel"]'), LIST('["Lob132
"]'))
INSERT INTO test.setName (PK, id, cities, lob) VALUES ('key2', 'id345', LIST('["Ctijs", "Ctdelhi"]'), LIST('["LOB23
1"]'))
INSERT INTO test.setName (PK, id, cities, lob) VALUES ('key3', 'id765', LIST('["Cthui"]'), LIST('["Lob875"]'))
select * from test.setName
select * from test.setName in LIST where cities = 'Cthdcn'
Output in aql:
aql> run 'list.aql'
TRUNCATE test
OK
DROP INDEX test.setName idx_city
Error: (201) Index does not exist on the system.
SELECT * FROM test
0 rows in set (0.156 secs)
OK
CREATE LIST INDEX idx_city ON test.setName (cities) STRING
OK, 1 index added.
INSERT INTO test.setName (PK, id, cities, lob) VALUES ('key1', 'id123', LIST('["Cthdcn", "Ctdel"]'), LIST('["Lob132"]'))
OK, 1 record affected.
INSERT INTO test.setName (PK, id, cities, lob) VALUES ('key2', 'id345', LIST('["Ctijs", "Ctdelhi"]'), LIST('["LOB231"]'))
OK, 1 record affected.
INSERT INTO test.setName (PK, id, cities, lob) VALUES ('key3', 'id765', LIST('["Cthui"]'), LIST('["Lob875"]'))
OK, 1 record affected.
select * from test.setName
+---------+------------------------------+--------------------+
| id | cities | lob |
+---------+------------------------------+--------------------+
| "id123" | LIST('["Cthdcn", "Ctdel"]') | LIST('["Lob132"]') |
| "id765" | LIST('["Cthui"]') | LIST('["Lob875"]') |
| "id345" | LIST('["Ctijs", "Ctdelhi"]') | LIST('["LOB231"]') |
+---------+------------------------------+--------------------+
3 rows in set (0.124 secs)
OK
select * from test.setName in LIST where cities = 'Cthdcn'
+---------+-----------------------------+--------------------+
| id | cities | lob |
+---------+-----------------------------+--------------------+
| "id123" | LIST('["Cthdcn", "Ctdel"]') | LIST('["Lob132"]') |
+---------+-----------------------------+--------------------+
1 row in set (0.001 secs)
OK
aql>
In Java, you will have to iterate through the recordset to get each record that satisfies the query.
RecordSet records = client.query( .....)
while (records.next()){
Record r = records.getRecord();
....
}
records.close()
I just tested the following code:
public void read () {
Record record = null;
Statement stmt = new Statement();
stmt.setSetName("setName");
stmt.setNamespace("test");
stmt.setIndexName("idx_city");
stmt.setFilter(Filter.contains("cities", IndexCollectionType.LIST, "Cthui"));
RecordSet recordSet = this.client.query(queryPolicy, stmt);
while (recordSet.next()) {
record = recordSet.getRecord();
System.out.println(record.toString());
}
}
and it worked for me.
$ java -jar ./target/dm-predicateFilter-1.0-full.jar
(gen:1),(exp:348432597),(bins:(id:id765),(cities:[Cthui]),(lob:[Lob875]))

JPA (Hibernate) / QueryDSL left join with condition doesn't work

I have two tables - user and booking. Each user may have many bookings (one-to-many relationship).
user: booking:
id | name | id | country | user_id | price |
-------------| ------------------------------------|
1 | Alice | 1 | Italy | 1 | 2000 |
2 | Bob | 2 | France | 1 | 2500 |
3 | Spain | 1 | 3000 |
I want to select all users and all bookings where booking's price is greater than 2000 using Query DSL. If a user doesn't have any bookings or bookings don't match the condition I still want to select this user.
First, let's have a look at how it would look like using a simple SQL left join query:
SELECT u.*, b.* FROM user u LEFT JOIN booking b ON u.id = b.user_id AND b.price > 2000
The above query should provide the following result:
id | name | id | country | user_id | price |
-------------|----------------------------------------|
1 | Alice | 2 | France | 1 | 2500 |
1 | Alice | 3 | Spain | 1 | 3000 |
2 | Bob | null | null | null | null |
Now I want to do it using JPA with Query DSL
JPA-related stuff:
#Entity
public class User {
#Id
private Long id;
private String name;
#OneToMany(cascade = ALL, fetch = EAGER, orphanRemoval = true, mappedBy = "user")
private List<Booking> bookings;
// getters and setters
}
#Entity
public class Booking {
#Id
private Long id;
private String name;
private Integer price;
#ManyToOne(fetch = LAZY)
#JoinColumn(name = "user_id")
private User user;
// getters and setters
}
Query DSL:
public List<User> getUsersAndBookings() {
QUser user = QUser.user;
QBooking booking = QBooking.booking;
JPAQuery<User> jpaQuery = new JPAQuery(entityManager);
List<User> result = jpaQuery.from(user).leftJoin(user.bookings, booking).on(booking.price.gt(2000)).fetchJoin().fetch();
return result;
}
In fact, this code is not working and I get the following exception:
org.hibernate.hql.internal.ast.QuerySyntaxException: with-clause not allowed on fetched associations; use filters [select user from com.example.demo.entity.User user left join fetch user.bookings as booking with booking.price > ?1]
The problem is that the condition clause is specified in on method - on(booking.price.gt(2000)).
After some research I found that this condition should be specified in where method and should look like this:
List<User> result = jpaQuery.from(user).leftJoin(user.bookings, booking).where(booking.price.gt(2000)).fetchJoin().fetch();
This works, but not how I would expect it to work, since it doesn't return ALL users, it returns only one user (Alice), which has some bookings, matching the condition clause. Basically, it just filters the merged table (result table after left join operation) and that's not what I'm looking for.
I want to retrieve all users, and if there are no any bookings for a specific user, then just have null instead of booking list for this user.
Please help, been struggling for hours without any success.
Versions used:
Spring Boot 2.0.2
Spring Data JPA 2.0.7
Hibernate 5.2.16.Final
QueryDSL 4.1.4

You can use isNull expression in where clause to get the rows that have null values.
Your query should be like this:
jpaQuery.from(user)
.leftJoin(user.bookings, booking)
.fetchJoin()
.where(booking.price.gt(2000).or(booking.id.isNull())).fetch();
Hibernate produced query:
select
user0_.id as id1_1_0_,
bookings1_.id as id1_0_1_,
user0_.name as name2_1_0_,
bookings1_.country as country2_0_1_,
bookings1_.price as price3_0_1_,
bookings1_.user_id as user_id4_0_1_,
bookings1_.user_id as user_id4_0_0__,
bookings1_.id as id1_0_0__
from
user user0_
left outer join
booking bookings1_
on user0_.id=bookings1_.user_id
where
bookings1_.id is null
or bookings1_.price>?

It seems there is no JPA way for this. But I got it fixed in Hibernate way, using Filters org.hibernate.annotations.Filter.
#Entity
#FilterDef(name = "anyName", parameters = {
#ParamDef(name = "price", type = "integer")
})
public class User {
#Id
private Long id;
private String name;
#OneToMany(cascade = ALL, fetch = EAGER, orphanRemoval = true, mappedBy = "user")
#Filter(name = "anyName", condition = "price > :inputPrice")
private List<Booking> bookings;
}
Before querying the db, you must enable this filter.
Session session = enityManager.unwrap(Session.class);
session.enableFilter("anyName").setParameter("inputPrice", 2000);
// fetch using hql or criteria; but don't use booking.price.gt(2000) or similar condition there
session.disableFilter("anyName");
Now the result will have a User even if all of his booking prices are below 2000 and bookings list will be empty as expected.
NOTE: The word price in condition should be exactly same as the db column name; not as the model property name.

Optimization: Getting SQL Query out of loop

I have two tables with a 1 to n relationship.
table hobbies has a foreign key to table users called "userid"
SELECT * FROM hobbies WHERE userid = 7
can have multiple results.
table users contains a list of user profile data and table hobbies contains a list of user hobbies. I want to print a list of profile info of multiple users with hobbies of each user. (hobbies concatenated into one String)
i currently have the following sql queries: (pseudocode):
ResultSet result = executeQuery("SELECT * FROM users;");
for each returned row: executeQuery("SELECT * FROM hobbies WHERE userid =" + result.getInt("ref"));
how do I get the SQL queries out of the loop to optimize performance with a big list of users?
I was trying to do a LEFT JOIN and then doing the WHERE ref= check in java instead of in SQL
problem is that I then get duplicate users and i only want to print one row for each user when processing the result set
also Im not sure if the JOIN is really an improvement in performance, because I have to process more rows.
table users
+--------+------+---------+--------+
| userid | name | country | telno |
+--------+------+---------+--------+
| 1 | John | USA | 123456 |
| 2 | Max | Germany | 345678 |
+--------+------+---------+--------+
+--------------+------------+
| userid |hobby |
+--------------+------------+
| 1 | football |
| 1 | basketball |
| 2 | TV |
| 2 | Music |
| 2 | football |
+--------------+------------+
example output:
John, USA, 123456, {football, basketball}
Max, Germany, 345678, {TV, Music, football}

This is most probably the fastest solution
SELECT name, country, telNo, GROUP_CONCAT(hobby)
FROM users u LEFT JOIN hobbies h ON u.id = h.userId
GROUP BY name, country, telNo
See https://dev.mysql.com/doc/refman/5.7/en/group-by-functions.html#function_group-concat for formatting options.
It's only good for the final output, e.g., if your hobbies contain commas, you wont't be able to parse them uniquely.

You can try :
SELECT h.userid, h.allyouneed FROM hobbies h, users u WHERE h.userid =u.userid
and get the info in one query

"SELECT * FROM hobbies h join users u on h.userid = u.userid WHERE userid = ?"
preparedStatement.setInt(result.getInt("ref"));
You can then save all the hobbies to a list similar to the 'Book' example below.
public static List<String> selectAll() throws SQLException {
PreparedStatement ps = null;
ResultSet rs = null;
// THE LIST OF BOOKS YOU WILL RETURN
List<String> books = new ArrayList<>();
String sql = "SELECT BOOK FROM BOOKs";
try(Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/bookshop", "root", "");){
ps = conn.prepareStatement(sql);
rs = ps.executeQuery();
while(rs.next()){
String book= rs.getString ("BOOK");
// ADD BOOK TO THE LIST
books.add(book);
}
}
finally{
ps.close();
rs.close();
}
// RETURN LIST OF ALL BOOKS
return books;
}

SELECT u.userid,u.name,u.country GROUP_CONCAT(hobby SEPARATOR ',')
FROM hobbies as h join users as u on h.userid=u.userid
where h.userid = ? GROUP BY u.userid,u.name,u.country;
assumming you have relationship on hobbies to users. the query will concat the columns of hobby of the join tables, and there will be one unique user per row.

Hibernate - Distinct Query returning two columns result

Sometime back I asked the question regarding how to do a Distinct query using Hibernate. Now that I'm past that milestone, there is another thing that I require. And that is, given the table,
---------------------------------------
| user_id | user_name | user_type |
---------------------------------------
| 1 | mark taylor | admin |
| 2 | bill paxton |co-ordinator|
| 1 | tony brooks | admin |
| 3 | ali jahan | developer |
---------------------------------------
I want to create a distinct query which returns the distinct user_type along with it's corresponding user_id. Please do note that the user_id for a particular user_type is same. So for example,
admin = 1
co-ordinator = 2
developer = 3
So the return I'm expecting is somewhat like a ArrayList or that sort which contains both values like
user_id,user_type
The code I've written to get Distinct UserType is as follows and I'm hoping there could be some modification to it to get the desired result.
public List<String> findDistinctUserName() throws HibernateException {
List<String> returnVal = new ArrayList<String>();
Criteria c = this.createCriteria();
c.setProjection(Projections.distinct(Projections.property("userType")));
c.addOrder(Order.asc("userType"));
List<String> userTypeList = c.list();
for(String userType : userTypeList) {
if(!userType.equalsIgnoreCase("")) {
returnVal.add(userType);
}
}
return returnVal;
}
Thank you for your answers in advance.

Try this:
criteria.setProjection(Projections.distinct(Projections.property("userType")), "userType");
Also u don't have to check for blank strings, try this:
criteria.add(Restrictions.ne("userType",""));

JAVA mySQL JOIN 2 tables

Hey guys I'm looking to get information out of 2 tables to create a JTABLE with that information.
The tables I am look at are 'shipments' and 'customers'
Where shipments takes the form of
shipNumber | shipperID | destID | size | weight
and customers takes the form of
ID | lastName | firstName | street | city | state | zip
The shipperID and destID both refer to a customer ID.
I am trying to get the city/state information out of the customers table that corresponds to the shipperID and destID.
I have tried the following
query = "SELECT shipments.shipNumber, customers.city, customers.state, customers.city, customers.state FROM shipments, customers WHERE shipments.shipperID = customers.ID";
Realizing that the duplicate customers.city/customers.state is populating the same information twice.
As previously said, I am trying to get the shipper city/state and destination city/state.
I also tried
query = "SELECT shipments.shipNumber, customers.city, customers.state, customers.city, customers.state, shipments.size"
+ " FROM shipments"
+ " INNER JOIN customers ON customers.id = shipments.shipperID";
Where this gives the same information.
I am not sure how to reference the destID = customer.id
Thanks,
Mike

The usual trick is to join with the customers table twice, once for the shipper and once for the destination:
SELECT shipments.shipNumber,
shipper.city, shipper.state,
dest.city, dest.state,
shipments.size
FROM shipments
INNER JOIN customers shipper ON shipper.id = shipments.shipperID
INNER JOIN customers dest ON dest.id = shipments.destID