I have a table like below,I'm using vertica data base sql
| Name | Cust ID |
| | 1 |
| | 2 |
|Prem | 2 |
For cust ID 1 the name is blank, so it should display and N/A, for cust ID 2 we have 2 entries, which are 1 is blank and 2 is Prem, so blank should be ignored and should display Prem.
The final out put should be like this,
|Name | Cust ID |
|N/A |1 |
|Prem |2 |
The final output should be like this,
|Name | Cust ID |
|N/A |1 |
|Prem |2 |
This works if the non-empty name of the same cust-id is always the same in multiple rows. Note that I use the NULL value for non-existent data. An empty string and NULL are two different things, for me.
WITH
indata("name",custid) AS (
SELECT NULL , 1
UNION ALL SELECT NULL , 2
UNION ALL SELECT 'Prem', 2
)
SELECT
IFNULL(MAX("name"),'N/A') AS "name"
, custid
FROM indata
GROUP BY custid;
-- out Null display is "(null)".
-- out name | custid
-- out ------+--------
-- out N/A | 1
-- out Prem | 2
Related
I am running a docker image of Vertica on windows. I have created a table in vertica with this schema (student_id is primary key)
dbadmin#d1f942c8c1e0(*)=> \d testschema.student;
List of Fields by Tables
Schema | Table | Column | Type | Size | Default | Not Null | Primary Key | Foreign Key
------------+---------+------------+-------------+------+---------+----------+-------------+-------------
testschema | student | student_id | int | 8 | | t | t |
testschema | student | name | varchar(20) | 20 | | f | f |
testschema | student | major | varchar(20) | 20 | | f | f |
(3 rows)
student_id is a primary key. I am testing loading data from csv file using copy command.
First I used insert - insert into testschema.student values (1,'Jack','Biology');
Then I created a csv file at /home/dbadmin/vertica_test directory -
vi student.csv
2,Kate,Sociology
3,Claire,English
4,Jack,Biology
5,Mike,Comp. Sci
Then I ran this command
copy testschema.students from '/home/dbadmin/vertica_test/student.csv' delimiter ',' rejected data as table students_rejected;
I tested the result
select * from testschema.student - shows 5 rows
select * from students_rejected; - no rows
Then I creates another csv file with bad data at /home/dbadmin/vertica_test directory
vi student_bad.csv
bad_data_type_for_student_id,UnaddedStudent, UnaddedSubject
6,Cassey,Physical Education
I added data from bad csv file
copy testschema.students from '/home/dbadmin/vertica_test/student.csv' delimiter ',' rejected data as table students_rejected;
Then I tested the output
select * from testschema.student - shows 6 rows <-- only one row got added. all ok
select * from students_rejected; - shows 1 row <-- bad row's entry is here. all ok
all looks good
Then I added the bad data again without the rejected data option
copy testschema.students from '/home/dbadmin/vertica_test/student_bad.csv' delimiter ',' ;
But now the entry with student id 6 got added again!!
student_id | name | major
------------+--------+--------------------
1 | Jack | Biology
2 | Kate | Sociology
3 | Claire | English
4 | Jack | Biology
5 | Mike | Comp. Sci
6 | Cassey | Physical Education <--
6 | Cassey | Physical Education <--
Shouldn't this have got rejected?
If you created your students with a command of this type:
DROP TABLE IF EXISTS students;
CREATE TABLE students (
student_id int
, name varchar(20)
, major varchar(20)
, CONSTRAINT pk_students PRIMARY KEY(student_id)
);
that is, without the explicit keyword ENABLED, then the primary key constraint is disabled. That is, you can happily insert duplicates, but will run into an error if you later want to join to the students table via the primary key column.
With the primary key constraint enabled ...
[...]
, CONSTRAINT pk_students PRIMARY KEY(student_id) ENABLED
[...]
I think you get the desired effect.
The whole scenario:
DROP TABLE IF EXISTS students;
CREATE TABLE students (
student_id int
, name varchar(20)
, major varchar(20)
, CONSTRAINT pk_students PRIMARY KEY(student_id) ENABLED
);
INSERT INTO students
SELECT 1,'Jack' ,'Biology'
UNION ALL SELECT 2,'Kate' ,'Sociology'
UNION ALL SELECT 3,'Claire','English'
UNION ALL SELECT 4,'Jack' ,'Biology'
UNION ALL SELECT 5,'Mike' ,'Comp. Sci'
UNION ALL SELECT 6,'Cassey','Physical Education'
;
-- out OUTPUT
-- out --------
-- out 6
COMMIT;
COPY students FROM STDIN DELIMITER ','
REJECTED DATA AS TABLE students_rejected;
6,Cassey,Physical Education
\.
-- out vsql:/home/gessnerm/._vfv.sql:4: ERROR 6745:
-- out Duplicate key values: 'student_id=6'
-- out -- violates constraint 'dbadmin.students.pk_students'
SELECT * FROM students;
-- out student_id | name | major
-- out ------------+--------+--------------------
-- out 1 | Jack | Biology
-- out 2 | Kate | Sociology
-- out 3 | Claire | English
-- out 4 | Jack | Biology
-- out 5 | Mike | Comp. Sci
-- out 6 | Cassey | Physical Education
SELECT * FROM students_rejected;
-- out node_name | file_name | session_id | transaction_id | statement_id | batch_number | row_number | rejected_data | rejected_data_orig_length | rejected_reason
-- out -----------+-----------+------------+----------------+--------------+--------------+------------+---------------+---------------------------+-----------------
-- out (0 rows)
And the only reliable check seems to be the ANALYZE_CONSTRAINTS() call ...
ALTER TABLE students ALTER CONSTRAINT pk_students DISABLED;
-- out Time: First fetch (0 rows): 7.618 ms. All rows formatted: 7.632 ms
COPY students FROM STDIN DELIMITER ','
REJECTED DATA AS TABLE students_rejected;
6,Cassey,Physical Education
\.
-- out Time: First fetch (0 rows): 31.790 ms. All rows formatted: 31.791 ms
SELECT * FROM students;
-- out student_id | name | major
-- out ------------+--------+--------------------
-- out 1 | Jack | Biology
-- out 2 | Kate | Sociology
-- out 3 | Claire | English
-- out 4 | Jack | Biology
-- out 5 | Mike | Comp. Sci
-- out 6 | Cassey | Physical Education
-- out 6 | Cassey | Physical Education
SELECT * FROM students_rejected;
-- out node_name | file_name | session_id | transaction_id | statement_id | batch_number | row_number | rejected_data | rejected_data_orig_length | rejected_reason
-- out -----------+-----------+------------+----------------+--------------+--------------+------------+---------------+---------------------------+-----------------
-- out (0 rows)
SELECT ANALYZE_CONSTRAINTS('students');
-- out Schema Name | Table Name | Column Names | Constraint Name | Constraint Type | Column Values
-- out -------------+------------+--------------+-----------------+-----------------+---------------
-- out dbadmin | students | student_id | pk_students | PRIMARY | ('6')
-- out (1 row)
I currently have a table:
id | info | value | date
1 | desc | description | 19-01-1990 10:01:23
2 | lname | Doe | 19-11-1990 10:01:23
1 | fname | John | 19-08-1990 10:01:23
1 | dob | dob | 19-05-1990 10:01:23
3 | fname | Jo | 19-01-1990 10:01:23
I would like to query and grab data and do joins with multiple tables later on, so I need it to be:
id | desc | lname | fname | dob | desc | date | ... |
1 | description | Doe | John | dob | description | 19-01-1990 10:01:23 | ... |
2 | ......... | ..... | Jo | | | ... | ... |
I have tried crosstab but it does not seem to work. Any help is appreciated
Your current table is a typical denormalized key value store. You may generate the normalized output you want by aggregating by id and then using max CASE expressions:
SELECT
id,
MAX(CASE WHEN info = 'desc' THEN value END) AS desc,
MAX(CASE WHEN info = 'lname' THEN value END) AS lname,
MAX(CASE WHEN info = 'fname' THEN value END) AS fname,
MAX(CASE WHEN info = 'dob' THEN value END) AS dob
FROM yourTable
GROUP BY
id
ORDER BY
id;
Note that I don't have any column for the date, as you did not give logic for which date value should be retained for each id.
As for the Spring part of your question, you would probably have to use a native query to execute the above.
I have a column ref_key in my table events in oracle database (plsql) where ref_key i am generating from creation_time in format
update events set ref_key= 'EV_'|| TOCHAR(creation_time, 'YYMMDD_HH24MISS');
now the problems is events are generated by batches from files so creation time for many rows can be same. There could be any number of duplicates in this column and I want it to be unique.
I already hada primary key, this is non-id field added recently and existing data needs to be updated to have a unique non null human readable value in this ref_key column.
I am getting data like column A and i want it like column B
Column A Column B or
EV_201005_151610 EV_201005_151610 EV_201005_151610_1
EV_201005_151610 EV_201005_151610_1 EV_201005_151610_2
EV_201005_151610 EV_201005_151610_2 EV_201005_151610_3
EV_201005_151610 EV_201005_151610_3 EV_201005_151610_4
EV_201005_151610 EV_201005_151610_4 EV_201005_151610_5
EV_201005_151711 EV_201005_151711 EV_201005_151711_1
EV_201005_151711 EV_201005_151711_1 EV_201005_151711_2
EV_201005_151711 EV_201005_151711_2 EV_201005_151711_3
I dont know how to do it. I can get all distinct values of ref_key where count(ref_key) > 1 . Then can append some sequence to it and reset the sequence after value changes, or anything like that. Or may be my first update query itself. Can Anyone please help with query in achieving this objective.
If you have a primary key column, say id, you could do this with a merge statement:
merge into events e
using (
select
id,
row_number() over(partition by to_char(creation_time, 'YYMMDD_HH24MISS') order by id) rn,
count(*) over(partition by to_char(creation_time, 'YYMMDD_HH24MISS')) cnt
from events
) e1
on (e1.id = e.id)
when matched then
update set e.ref_key = 'EV_'
|| to_char(creation_time, 'YYMMDD_HH24MISS')
|| case when e1.cnt > 1 then '_' || to_char(e1.rn) end
Demo on DB Fiddle:
Sample data:
ID | CREATION_TIME | REF_KEY
-: | :------------------ | :------
1 | 2020-10-05 11:03:57 | null
2 | 2020-10-05 11:03:57 | null
3 | 2020-10-04 11:03:57 | null
4 | 2020-10-04 11:03:57 | null
5 | 2020-10-04 11:03:57 | null
6 | 2020-10-03 11:03:57 | null
Results:
ID | CREATION_TIME | REF_KEY
-: | :------------------ | :-----------------
1 | 2020-10-05 11:03:57 | EV_201005_110357_1
2 | 2020-10-05 11:03:57 | EV_201005_110357_2
3 | 2020-10-04 11:03:57 | EV_201004_110357_1
4 | 2020-10-04 11:03:57 | EV_201004_110357_2
5 | 2020-10-04 11:03:57 | EV_201004_110357_3
6 | 2020-10-03 11:03:57 | EV_201003_110357
I have this written and working as a raw SQL query, but I am trying to convert it to a more Laravel eloquent / query builder design instead of just a raw query.
My table structure like this:
Table One (Name model)
______________
| id | name |
|------------|
| 1 | bob |
| 2 | jane |
--------------
Table Two (Date Model)
_________________________________
| id | table_1_id | date |
|-------------------------------|
| 1 | 1 | 2000-01-01 |
| 2 | 1 | 2000-01-31 |
| 4 | 1 | 2000-02-28 |
| 5 | 1 | 2000-03-03 |
| 6 | 2 | 2000-01-03 |
| 7 | 2 | 2000-01-05 |
---------------------------------
I am returning only the the highest (most recent) dates from table 2 (Dates model) that match the user bob from table 1 (Name model).
For instance, in the example above, I return this from my query
2000-01-31
2000-02-28
2000-03-03
Here is what I am doing now (which works), but i'm just not sure how to use YEAR, MONTH and MAX with laravel.
DB::select(
DB::raw("
SELECT MAX(date) as max_date
FROM table_2
INNER JOIN table_1 ON table_1.id = table_2.table_1_id
WHERE table_1.name = 'bob'
GROUP BY YEAR(date), MONTH(date)
ORDER BY max_date DESC
")
);
Try this code if any problem then,
DB::table('table_1')->join('table_2', 'table_1.id','=','table_2.table_1_id')
->select(DB::raw('MAX(date) as max_date'),DB::raw('YEAR(date) year, MONTH(date) month'),'table_1.name')
->where('name','bob')
->groupBy('year','month')
->orderBy('max_date')
->get();
If any problem with above code then feel free to ask.
I have got a table with name table_listnames whose structure is given below
mysql> desc table_listnames;
+-------+--------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-------+--------------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| name | varchar(255) | NO | | NULL | |
+-------+--------------+------+-----+---------+----------------+
2 rows in set (0.04 sec)
It has got sample data as shown
mysql> select * from table_listnames;
+----+------------+
| id | name |
+----+------------+
| 6 | WWW |
| 7 | WWWwww |
| 8 | WWWwwws |
| 9 | WWWwwwsSSS |
| 10 | asdsda |
+----+------------+
5 rows in set (0.00 sec)
I have a requirement where if name not found under the table , i need to insert or else do nothing
I am achieving it this way
String sql = "INSERT INTO table_listnames (name) SELECT name FROM (SELECT ?) AS tmp WHERE NOT EXISTS (SELECT name FROM table_listnames WHERE name = ?) LIMIT 1";
pst = dbConnection.prepareStatement(sql);
pst.setString(1, salesName);
pst.setString(2, salesName);
pst.executeUpdate();
Is it possible to know the id of the record of the given name in this case