I have a specific query with joins and aliases, and I need to retrieve columns name for a REST request in Talend.
I'm using Talend Open Studio for Data Integration 6.2 and I've got an Oracle 11g database with a read-only account. I can execute scripts with Talend, For example the query:
select
u.name as "user",
f.name as "food",
e.rate
from
Users as u
join Eval as e on u.user_id = e.user_id
join Food as f on e.food_id = f.food_id
where
1 = 1
should give the following result:
+------+--------+------+
| user | food | rate |
+------+--------+------+
| Baba | Donuts | 16.0 |
| Baba | Cheese | 20.0 |
| Keke | Pasta | 12.5 |
| Keke | Cheese | 15.0 |
+------+--------+------+
And I try to get the columns (in the right order) as follows by using scripts or Talend:
+--------+
| Column |
+--------+
| user |
| food |
| rate |
+--------+
Is there a way to query the Oracle database to get the columns or using talend to retrieve them?
UPDATE
Thanks to Marmite Bomber, a duplicate has been identified here for the Oracle approach. Now we need a Talend approach to the problem.
You can try this on a tJavaRow, following your DBInput component :
for (java.lang.reflect.Field field: row1.getClass().getDeclaredFields()) {
context.columnName = field.getName();
System.out.println("Field name is " + context.columnName );
}
Spotted on talend help center here : https://community.talend.com/t5/Design-and-Development/resolved-how-to-get-the-column-names-in-a-data-flow/td-p/99172
You can extend this, and put the column list on your outputflow :
//add this inside the loop, and 'columnNames' as an output row in tJavaRow schema
output_row.columnNames+=context.columnName+";";
With a tNormalize after tJavaRow, you shoud get the expected result.
Here´s a link to an oracle community thread which should answer your question
community.oracle.com
I am not able to write a comment, so posting this as an answer:
SELECT column_name
FROM all_tab_cols
WHERE table_name = 'table_name_here'
Related
I am looking for a SQL Server query that could transfer source SQL table data:
TextID | Text | LanguageID
-------|-------|-------------------------------------
app.aa | Hi | 6a13ea09-46ea-4c93-9b6a-e26bdc6ff4d8
app.cc | Hund | 0c894bb7-4937-4903-906a-d1b1dd64935c
app.aa | Hallo | 0c894bb7-4937-4903-906a-d1b1dd64935c
app.cc | Dog | 6a13ea09-46ea-4c93-9b6a-e26bdc6ff4d8
app.bb | Star | 6a13ea09-46ea-4c93-9b6a-e26bdc6ff4d8
...
into table like this one:
TextID | Original | Translated
-------|----------|-----------
app.aa | Hi | Hallo
app.bb | Star | -
app.cc | Dog | Hund
...
so that I can use it as a DataSource for GridView in ASP .NET. Thank you in advance for your help.
Whenever you need to combine data from two different rows into one, you need to join. For example:
select src.TextID "TextID", src.Text "Original", tr.Text "Translated"
from source_table src
left join source_table tr
on src.TextID = tr.TextID
and src.LangID = 'xxx' -- xxx is the source language id
and tr.LangID = 'yyy' -- yyy is the target language id
The left join ensures that untranslated words are included with a null translated value. To make a table for your DataSource, you'll need to wrap create table (or maybe create view) around the select:
create table translations as
select ...
I'm trying to create a query in SQL Server to determine how many times a person's name shows up in a list, but also that list will be unknown, so I would have to get the actual name from the previous select index... It's hard to explain so I'll show the query first and hopefully someone can help.
SELECT
SpeakerName, Spoken,
(SELECT COUNT(SpeakerName)
FROM tbl_SpeakerCard_Log
WHERE SpeakerName = 'SpeakerName[i]' AND SpeakDate = '3-9-16') as TimesSpoken
FROM
tbl_SpeakerCard_Log
WHERE
AID = ####
ORDER BY
GeneralComment ASC
So basically, in SpeakerName[i], I'd like to somehow get the SpeakerName from the outer Select. The output should come out something like this
+-------------+--------+-------------+
| SpeakerName | Spoken | TimesSpoken |
+-------------+--------+-------------+
| Holly | 0 | 4 |
| Robert | 1 | 5 |
| Mike | 1 | 2 |
+-------------+--------+-------------+
Try this:
select x.SpeakerName, x.Spoken, COUNT(*) as TimesSpoken
from tbl_SpeakerCard_Log x
WHERE AID = ####
and x.SpeakDate = '3-9-16'
group by x.SpeakerName, x.Spoken
Don't have SSMS installed on this computer so can't test it.
I'm a bit stumped on a query I need to write for work. I have the following two tables:
|===============Patterns==============|
|type | bucket_id | description |
|-----------------------|-------------|
|pattern a | 1 | Email |
|pattern b | 2 | Phone |
|==========Results============|
|id | buc_1 | buc_2 |
|-----------------------------|
|123 | pass | |
|124 | pass |fail |
In the results table, I can see that entity 124 failed a validation check in buc_2. Looking at the patterns table, I can see bucket 2 belongs to pattern b (bucket_id corresponds to the column name in the results table), so entity 124 failed phone validation. But how do I write a query that joins these two tables on the value of one of the columns? Limitations to how this query is going to be called will most likely prevent me from using any cursors.
Some crude solutions:
SELECT "id", "description" FROM
Results JOIN Patterns
ON "buc_1" = 'fail' AND "bucket_id" = 1
union all
SELECT "id", "description" FROM
Results JOIN Patterns
ON "buc_2" = 'fail' AND "bucket_id" = 2
Or, with a very probably better execution plan:
SELECT "id", "description" FROM
Results JOIN Patterns
ON "buc_1" = 'fail' AND "bucket_id" = 1
OR "buc_2" = 'fail' AND "bucket_id" = 2;
This will report all failure descriptions for each id having a fail case in bucket 1 or 2.
See http://sqlfiddle.com/#!4/a3eae/8 for a live example
That being said, the right solution would be probably to change your schema to something more manageable. Say by using an association table to store each failed test -- as you have in fact here a many to many relationship.
An other approach if you are using Oracle ≥ 11g, would be to use the UNPIVOT operation. This will translate columns to rows at query execution:
select * from Results
unpivot ("result" for "bucket_id" in ("buc_1" as 1, "buc_2" as 2))
join Patterns
using("bucket_id")
where "result" = 'fail';
Unfortunately, you still have to hard-code the various column names.
See http://sqlfiddle.com/#!4/a3eae/17
It looks to me that what you really want to know is the description(in your example Phone) of a Pattern entry given the condition that the bucket failed. Regardless of the specific example you have you want a solution that fulfills that condition, not just your particular example.
I agree with the comment above. Your bucket entries should be tuples(rows) and not arguments, and also you should share the ids on each table so you can actually join them. For example, Consider adding a bucket column and index their number then just add ONE result column to store the state. Like this:
|===============Patterns==============|
|type | bucket_id | description |
|-----------------------|-------------|
|pattern a | 1 | Email |
|pattern b | 2 | Phone |
|==========Results====================|
|entity_id | bucket_id |status |
|-------------------------------------|
|123 | 1 |pass |
|124 | 1 |pass |
|123 | 2 | |
|124 | 2 |fail |
1.-Use an Inner Join: http://www.w3schools.com/sql/sql_join_inner.asp and the WHERE clause to filter only those buckets that failed:
2.-Would this example help?
SELECT Patterns.type, Patterns.description, Results.entity_id,Results.status
INNER JOIN Results
ON
Patterns.bucket_id=Results.bucket_id
WHERE
Results.status=fail
Lastly, I would also add a primary_key column to each table to make sure indexing is faster for each unique combination.
Thanks!
I have some problems regarding a pivot query. I am new to this. So look for something in the internet so I found dozens of them. So I decided to follow this Link. Been practice but seems like I ran into some obvious error.
My code is:
select
risk, [Quick] AS Quick, [Brown] AS Brown, [Fox] AS Fox
from
(select risk, site
from tst) as ps
PIVOT
(
count(risk)
for site in ([Brown], [Brown], [Fox])
) AS pvt
But it is throwing an error:
Invalid column name 'risk'.
Basically I want to have an output like this:
|Foo | Quick | Brown | Fox |
| 1 | 10 | 3 | 2 |
| 2 | 5 | 4 | 4 |
| 3 | 4 | 1 | 5 |
| 4 | 2 | 3 | 7 |
| 5 | 3 | 2 | 1 |
Something like that. Just counting how many there is in a specific number. Any help would be much appreciated. Thanks
The problem with your existing query is you are using the column risk in your final select list as well as inside of the aggregate function. Once you've counted the risk values for each site this is not available to display.
To get around this you can add a second version of the risk column to your subquery similar to the following. You then count this other column of risk and display one in the final select:
select risk, [ADAB] AS ADAB, [Bahrain] AS Bahrain, [Thumrait] AS Thumrait
from
(
select risk, piv_risk = risk, site
from qcqcif
) as ps
PIVOT
(
count(piv_risk)
for site in ([ADAB], [Bahrain], [Thumrait])
) AS pvt;
See SQL Fiddle with Demo
I have been using sql queries in my rails code which needs to be transitioned to Active Record Query. I haven't used Active Record before so i tried going through http://guides.rubyonrails.org/active_record_querying.html to get the proper syntax to be able to switch to this method of getting the data. I am able to convert the simple queries into this format but there are other complex queries like
SELECT b.owner,
Sum(a.idle_total),
Sum(a.idle_monthly_usage)
FROM market_place_idle_hosts_summaries a,
(SELECT DISTINCT owner,
hostclass,
week_number
FROM market_place_idle_hosts_details
WHERE week_number = '#{week_num}'
AND Year(updated_at) = '#{year_num}') b
WHERE a.hostclass = b.hostclass
AND a.week_number = b.week_number
AND Year(updated_at) = '#{year_num}'
GROUP BY b.owner
ORDER BY Sum(a.idle_monthly_usage) DESC
which i need in Active Record format but because of the complexity I am stuck as to how to proceed with the conversion.
The output of the query is something like this
+----------+-------------------+---------------------------+
| owner | sum(a.idle_total) | sum(a.idle_monthly_usage) |
+----------+-------------------+---------------------------+
| abc | 485 | 90387.13690185547 |
| xyz | 815 | 66242.01857376099 |
| qwe | 122 | 11730.609939575195 |
| asd | 80 | 9543.170425415039 |
| zxc | 87 | 8027.090087890625 |
| dfg | 67 | 7303.070011138916 |
| wqer | 76 | 5234.969814300537 |
Instead of converting it to an active record, you can use the find_by_sql method. Since your query is a bit complex.
You can use also use ActiveRecord::Base.connection, directly to fetch the records.
like this,
ActiveRecord::Base.connection.execute("your query")
You can create the subquery apart with ActiveRecord and convert it to sql using to_sql
Then use joins to join your table a with the b one, that it is the subquery. Note also the use of the active record clauses select, where, group and order that are basically what you need to build this complex SQL query in ActiveRecord.
Something similar to the following will work:
subquery = SubModel.select("DISTINCT ... ").where(" ... ").to_sql
Model.select("b.owner, ... ")
.joins("JOIN (#{subquery}) b ON a.hostclass = b.hostclass")
.where(" ... ")
.group("b.owner")
.order("Sum(a.idle_monthly_usage) DESC")