Ignite SQL error 50000 when inserting on refence table - mariadb

Question

I'm currently researching on Ignite, and I used web-console's automatic RDBMS integration feature for my MariaDB persistent store.
This made ignite configure a cache for one of my reference table which has a many-to-many relationship, with 2 fields, both primary-keys.
Example Structure in the persistent store:
CREATE TABLE `user_category` (
`USER_ID` bigint(20) NOT NULL,
`CATEGORY` bigint(20) NOT NULL,
PRIMARY KEY (`USER_ID`,`CATEGORY`),
KEY `FK48520EF2B4BDA303` (`USER_ID`),
KEY `FK48520EF2C941D634` (`CATEGORY`),
CONSTRAINT `FK48520EF2B4BDA303` FOREIGN KEY (`USER_ID`) REFERENCES `ctrl_app_user` (`USER_ID`) ON DELETE CASCADE ON UPDATE CASCADE,
CONSTRAINT `FK48520EF2C941D634` FOREIGN KEY (`CATEGORY`) REFERENCES `request_category` (`CATEGORY_ID`) ON DELETE CASCADE ON UPDATE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
This made web-console configure the cache like this:
ArrayList<QueryEntity> qryEntities = new ArrayList<>();
QueryEntity qryEntity = new QueryEntity();
qryEntity.setKeyType("model.UserCategoryKey");
qryEntity.setValueType("model.UserCategory");
qryEntity.setTableName("user_category");
HashSet<String> keyFields = new HashSet<>();
keyFields.add("userId");
keyFields.add("category");
qryEntity.setKeyFields(keyFields);
LinkedHashMap<String, String> fields = new LinkedHashMap<>();
fields.put("userId", "java.lang.Long");
fields.put("category", "java.lang.Long");
qryEntity.setFields(fields);
HashMap<String, String> aliases = new HashMap<>();
aliases.put("userId", "USER_ID");
qryEntity.setAliases(aliases);
ArrayList<QueryIndex> indexes = new ArrayList<>();
QueryIndex index = new QueryIndex();
index.setName("FK48520EF2B4BDA303");
index.setIndexType(QueryIndexType.SORTED);
LinkedHashMap<String, Boolean> indFlds = new LinkedHashMap<>();
indFlds.put("userId", false);
index.setFields(indFlds);
indexes.add(index);
index = new QueryIndex();
index.setName("FK48520EF2C941D634");
index.setIndexType(QueryIndexType.SORTED);
indFlds = new LinkedHashMap<>();
indFlds.put("category", false);
index.setFields(indFlds);
indexes.add(index);
qryEntity.setIndexes(indexes);
qryEntities.add(qryEntity);
ccfg.setQueryEntities(qryEntities);
return ccfg;
I am able to retrieve data from ignite properly using its standard SQL.
However, when trying to insert data to that cache, I am getting error 50000 which according to Ignite documentation, is a query that is unsupported by ANSI-99.
Documentation also mentioned to take a look into the SQLException message but the message only mentioned the error 50000.
sample insert statement:
insert into USER_CATEGORY (USER_ID, CATEGORY) values (1, 1);
Thanks in Advance.

Answer 1

Most likely you need to specify a schema name (cache name) for the query:
insert into "YourCacheName".USER_CATEGORY (USER_ID, CATEGORY) values (1, 1);

Answer 2

So, for everyone who will experience this issue in the future, I've resolved the issue by removing the query entity keys.
keyFields.add("userId");
keyFields.add("category");
Ignite treats keys in a reference table/cache as unique, so both columns needed to be unique, this is not applicable for reference tables with many-to-many relationship since this design is bound to have duplicates for each column.
Thanks for those who took a look at this issue!~