I run the following queries:
CREATE INDEX ON :Role(id)
+-------------------+
| No data returned. |
+-------------------+
Indexes added: 1
CREATE (:Role {id:'abc'})
+-------------------+
| No data returned. |
+-------------------+
Nodes created: 1
Properties set: 1
Labels added: 1
And next, for some reason, the index is not used when I try to fetch the Role that I just created. Can you explain why?
neo4j-sh (?)$ PROFILE MATCH (role:Role {id:'abc'})
> RETURN role.id;
+---------+
| role.id |
+---------+
| "abc" |
+---------+
1 row
7 ms
Compiler CYPHER 2.2
Planner COST
Projection
|
+Filter
|
+NodeByLabelScan
+-----------------+---------------+------+--------+---------------+----------------------------+
| Operator | EstimatedRows | Rows | DbHits | Identifiers | Other |
+-----------------+---------------+------+--------+---------------+----------------------------+
| Projection | 1 | 1 | 1 | role, role.id | role.id |
| Filter | 1 | 1 | 5 | role | role.id == { AUTOSTRING0} |
| NodeByLabelScan | 6 | 5 | 6 | role | :Role |
+-----------------+---------------+------+--------+---------------+----------------------------+
Total database accesses: 12
You forgot to use the index.
Try this:
MATCH (role:Role)
USING INDEX role:Role(id)
WHERE role.id='abc'
RETURN role.id
Projection
|
+Expand(All)
|
+NodeIndexSeek
Total database accesses: 4
Related
I am working on a PowerBI report that is grabbing information from SQL and I cannot find a way to solve my problem using PowerBI or how to write the required code. My first table, Certifications, includes a list of certifications and required trainings that must be obtained in order to have an active certification.
My second table, UserCertifications, includes a list of UserIDs, certifications, and the trainings associated with a certification.
How can I write a SQL code or PowerBI measure to tell if a user has all required trainings for a certification? ie, if UserID 1 has the A certification, how can I verify that they have the TrainingIDs of 1, 10, and 150 associated with it?
Certifications:
CertificationsTable
UserCertifications:
UserCertificationsTable
This is a DAX pattern to test if contains at least some values.
| Certifications |
|----------------|------------|
| Certification | TrainingID |
|----------------|------------|
| A | 1 |
| A | 10 |
| A | 150 |
| B | 7 |
| B | 9 |
| UserCertifications |
|--------------------|---------------|----------|
| UserID | Certification | Training |
|--------------------|---------------|----------|
| 1 | A | 1 |
| 1 | A | 10 |
| 1 | A | 300 |
| 2 | A | 150 |
| 2 | B | 9 |
| 2 | B | 90 |
| 3 | A | 7 |
| 4 | A | 1 |
| 4 | A | 10 |
| 4 | A | 150 |
| 4 | A | 1000 |
In the above scenario, DAX needs to find out if the mandatory trainings (Certifications[TrainingID]) by Certifications[Certification] is completed by
UserCertifications[UserID ]&&UserCertifications[Certifications] partition.
In the above scenario, DAX should only return true for UserCertifications[UserID ]=4 as it is the only User that completed at least all the mandatory trainings.
The way to achieve this is through the following measure
areAllMandatoryTrainingCompleted =
VAR _alreadyCompleted =
CONCATENATEX (
UserCertifications,
UserCertifications[Training],
"-",
UserCertifications[Training]
) // what is completed in the fact Table; the fourth argument is very important as it decides the sort order
VAR _0 =
MAX ( UserCertifications[Certification] )
VAR _supposedToComplete =
CONCATENATEX (
FILTER ( Certifications, Certifications[Certification] = _0 ),
Certifications[TrainingID],
"-",
Certifications[TrainingID]
) // what is comeleted in the training Table; the fourth argument is very important as it decides the sort order
VAR _isMandatoryTrainingCompleted =
CONTAINSSTRING ( _alreadyCompleted, _supposedToComplete ) // CONTAINSSTRING (<Within Text>,<Search Text>); return true false
RETURN
_isMandatoryTrainingCompleted
I have a one tables in Postgresql and cannot find how to build a query.
The table contains columns nr_serii and deleteing_time. I trying to count nr_serii and substract from this positions with deleting_time.
My query:
select nr_serii , count(nr_serii ) as ilosc,count(deleting_time) as ilosc_delete
from MyTable
group by nr_serii, deleting_time
output is:
+--------------------+
| "666666";1;1 |
| "456456";1;0 |
| "333333";3;0 |
| "333333";1;1 |
| "111111";1;1 |
| "111111";3;0 |
+--------------------+
The part of table with raw data:
+--------------------------------+
| "666666";"2020-11-20 14:08:13" |
| "456456";"" |
| "333333";"" |
| "333333";"" |
| "333333";"" |
| "333333";"2020-11-20 14:02:23" |
| "111111";"" |
| "111111";"" |
| "111111";"2020-11-20 14:08:04" |
| "111111";"" |
+--------------------------------+
And i need substract column ilosc and column ilosc_delete
example:
nr_serii:333333 ilosc:3-1=2
Expected output:
+-------------+
| "666666";-1 |
| "456456";1 |
| "333333";2 |
| "111111";2 |
| ... |
+-------------+
I think this is very simple solution for this but i have empty in my head.
I see what you want now. You want to subtract the number where deleting_time is not null from the ones where it is null:
select nr_serii,
count(*) filter (where deleting_time is null) - count(deleting_time) as ilosc_delete
from MyTable
group by nr_serii;
Here is a db<>fiddle.
Assume there is a table employee:
+-----------+------------------+
| col_name | data_type |
+-----------+------------------+
| id | string |
| perf | map<string,int> |
+-----------+------------------+
and the data inside this table:
+-----+------------------------------------+--+
| id | perf |
+-----+------------------------------------+--+
| 1 | {"job":80,"person":70,"team":60} |
| 2 | {"job":60,"team":80} |
| 3 | {"job":90,"person":100,"team":70} |
+-----+------------------------------------+--+
I tried the following two queries but they all return the same result:
1. select explode(perf) from employee;
2. select key,value from employee lateral view explode(perf) as key,value;
The result:
+---------+--------+--+
| key | value |
+---------+--------+--+
| job | 80 |
| team | 60 |
| person | 70 |
| job | 60 |
| team | 80 |
| job | 90 |
| team | 70 |
| person | 100 |
+---------+--------+--+
So, what is the difference between them? I did not find suitable examples. Any help is appreciated.
For your particular case both queries are OK. But you can't use multiple explode() functions without lateral view. So, the query below will fail:
select explode(array(1,2)), explode(array(3, 4))
You'll need to write something like:
select
a_exp.a,
b_exp.b
from (select array(1, 2) as a, array(3, 4) as b) t
lateral view explode(t.a) a_exp as a
lateral view explode(t.b) b_exp as b
I'm considering aerospike for one of our projects. So I currently created a 3 node cluster and loaded some data on it.
Sample data
ns: imei
set: imei_data
+-------------------+-----------------------+-----------------------+----------------------------+--------------+--------------+
| imsi | fcheck | lcheck | msc | fcheck_epoch | lcheck_epoch |
+-------------------+-----------------------+-----------------------+----------------------------+--------------+--------------+
| "413010324064956" | "2017-03-01 14:30:26" | "2017-03-01 14:35:30" | "13d20b080011044917004100" | 1488358826 | 1488359130 |
| "413012628090023" | "2016-09-21 10:06:49" | "2017-09-16 13:54:40" | "13dc0b080011044917006100" | 1474432609 | 1505550280 |
| "413010130130320" | "2016-12-29 22:05:07" | "2017-10-09 16:17:10" | "13d20b080011044917003100" | 1483029307 | 1507546030 |
| "413011330114274" | "2016-09-06 01:48:06" | "2017-10-09 11:53:41" | "13d20b080011044917003100" | 1473106686 | 1507530221 |
| "413012629781993" | "2017-08-16 16:03:01" | "2017-09-13 18:10:48" | "13dc0b080011044917004100" | 1502879581 | 1505306448 |
Then I created a secondary index on lcheck_epoch using AQL since I want to query based on date.
create index idx_lcheck on imei.imei_data (lcheck_epoch) NUMERIC
+--------+----------------+-----------+-------------+-------+--------------+----------------+-----------+
| ns | bin | indextype | set | state | indexname | path | type |
+--------+----------------+-----------+-------------+-------+--------------+----------------+-----------+
| "imei" | "lcheck_epoch" | "NONE" | "imei_data" | "RW" | "idx_lcheck" | "lcheck_epoch" | "NUMERIC" |
+--------+----------------+-----------+-------------+-------+--------------+----------------+-----------+
When I execute
select imsi from imei.imei_data where idx_lcheck=1476165806
I'm getting
Error: (204) AEROSPIKE_ERR_INDEX
Please explain.
You're using the index name, not the bin name, in your query. Try this:
SELECT imsi FROM imei.imei_data WHERE lcheck_epoch=1476165806
Or
SELECT imsi FROM imei.imei_data WHERE lcheck_epoch BETWEEN 1490000000 AND 1510000000
Just a note, you can do much more complex queries using predicate filtering through several of the language clients (Java, C, C#, Go). For example the PredExp class of the Java client (see examples.)
I have a table in Access named Spells which holds patient spells (where a patient has a spell within a hospital). It's structure is as below:
| ID | SpellID | MultipleSpell | FirstSpell | LastSpell |
|----|---------|---------------|------------|-----------|
| 1 | 1 | False | | |
| 2 | 2 | True | | |
| 3 | 2 | True | | |
| 4 | 3 | False | | |
| 5 | 4 | False | | |
| 6 | 5 | True | | |
| 7 | 5 | True | | |
| 8 | 5 | True | | |
The MultipleSpell column indicates that there are multiple occurrences of the spell within the table.
I'd like to run query which would update the FirstSpell column to True for records with the IDs of 1,2,4,5,6. So basically, where a Spell is the first one in the table, it should be marked, in the FirstSpell column.
I would also then like to update the LastSpell column to True for records with the IDs of 1,3,4,5,8.
The reasoning for this (if you're interested) is that the table links to a separate table containing the name of wards. It would be useful to link to this other table and indicate whether the ward is the admitting ward (FirstSpell) or the discharging ward (LastSpell)
You can update the first using:
update spells
set firstspell = 1
where id = (select min(id)
from spells as s2
where spells.spellid = s2.spellid
);
Similar logic (using max()) can be used for the last spell.