I am creating a view merging two tables with some similar fields and some dissimilar fields. I have this 95% working but there is one field from table A that matches up with a field from table B but only if you use that field from B as a join to pull a field from table C. The only part of the code below that isn't working is the JOIN. I could just put both of the fields in and do the logic to get provider_id from the ehruser_id in the model, but I feel like it should be doable in the SQL and I just don't have the knowledge to get that last bit working yet
DROP VIEW IF EXISTS vunifiedschedule CASCADE;
CREATE VIEW vunifiedschedule AS
SELECT
schedule_block.id as vid,
schedule_block.reason as vblock_reason,
NULL as vappointment_reason_id,
schedule_block.when_ts as vwhen,
schedule_block.deleted_ts as vdeleted_when,
schedule_block.placeofservice_id as vlocation_id,
schedule_block.duration as vduration,
true as vappointment_book,
schedule_block.note as vnote
FROM schedule_block
LEFT JOIN ( SELECT id FROM provider) as vprovider_id ON provider.ehruser_id = schedule_block.ehruser_id
UNION ALL
SELECT
appointment.id AS vid,
NULL as vblock_reason,
appointment.appointmentreason_id AS vappointment_reason_id,
appointment.appt_when AS vwhen,
appointment.deleted_when AS vdeleted_when,
appointment.location_id AS vlocation_id,
appointment.visit_length AS vduration,
appointment.appointment_book as vappointment_book,
appointment.note AS vnote,
appointment.provider_id as vprovider_id
FROM appointment
The error I get is
ERROR: missing FROM-clause entry for table "provider"
LINE 14: ...ELECT id FROM provider) as vprovider_id ON provider.e...
The error is pretty clear. You have no provider. I think you intend:
FROM schedule_block LEFT JOIN
( SELECT id FROM provider) vprovider_id
ON vprovider.ehruser_id = schedule_block.ehruser_id
--------^
However the subquery is unnecessary:
FROM schedule_block LEFT JOIN
provider
ON provider.ehruser_id = schedule_block.ehruser_id
1st select stmt of view has 9 columns but 2nd select stmt has 10 columns. This view will error with message "Query block has incorrect number of result columns
You selected 9 columns from the first table and 10 from the second, when using union you must have the same number of columns in both queries and the type columns selected must match.
Related
In this query I inserting records into a new empty table I created. These records are derived from another table where I am left joining that table to itself, in order to output records that are not included in the recent table that is appended on top of an older table. So basically it outputs records that were deleted.
CREATE DEFINER=`definer` PROCEDURE `stored_procedure_name`()
MODIFIES SQL DATA
SQL SECURITY INVOKER
BEGIN
START TRANSACTION;
INSERT INTO exceptions_table (
`insert_date`,
`updated`,
`account_number`,
`id_number`)
SELECT
`insert_date`,
`updated`,
`account_number`,
`id_number`
FROM original_table ot1
LEFT JOIN original_table ot2
ON ot1.`account_number` = vdcaas2.`account_number`
AND ot2.`insert_date` = '2022-12-20'
WHERE ot1.`insert_date` = '2022-12-10'
AND ot2.`account_number` IS NULL;
COMMIT;
END
I get an error stating: "SQL Error: Column "insert_date" in field list is ambiguous.
I'm not sure why because I have specified which table I am grabbing "insert_date" from when INSERTING and when SELECTING and JOINING..
Every row in your query has two columns called insert_date: one from the table you've aliased as "ot1", and one from the table (as it happens, the same table) you've aliased as "ot2".
The database system doesn't know which one you want, so you have to tell it by writing either "ot1.insert_date" or "ot2.insert_date", just as you do elsewhere in the query:
... ot2.`insert_date` = '2022-12-20'
...
... ot1.`insert_date` = '2022-12-10'
The same is true of the other columns you've listed to select.
You need to change this
SELECT
`insert_date`,
`updated`,
`account_number`,
`id_number`
to this
SELECT
ot1.`insert_date`,
ot1.`updated`,
ot1.`account_number`,
ot1.`id_number`
or this
SELECT
ot2.`insert_date`,
ot2.`updated`,
ot2.`account_number`,
ot2.`id_number`
or some combination
Issue
SQL Error: Column "insert_date" in field list is ambiguous error means that the query is trying to reference the "insert_date" column from both tables, ot1 and ot2.
Try the following:
SELECT
ot1.`insert_date`,
ot1.`updated`,
ot1.`account_number`,
ot1.`id_number`
Also, you have a typo in your query:
ON ot1.`account_number` = vdcaas2.`account_number` -> ON ot1.`account_number` = ot2.`account_number`
SELECT
ID, PRIM_EMAIL, SEC_EMAIL, PHONE
FROM
STUDENTS.RECORDS
WHERE
ID IN (SELECT ID FROM STUDENTS.INFO WHERE ROLL_NO = '554')
UNION
SELECT NAME
FROM STUDENTS.INFO
WHERE ROLL_NO = '554';
Here Roll_No is a user inserted data so for now I have hard coded it. Basically with the help of ROLL_NO I sort the STUDENTS_INFO table from where I get the ID and based on that I try to get PRIM_EMAIL, SEC_EMAIL, PHONE from the STUDENTS.RECORDS table while matching the foreign keys of both the tables. In addition to the current result set I also want to have the prov_name column.
Any help is very much appreciated. Thank you!
I suspect that you want to put all this information on the same row, which suggests a join rather than union all:
select
r.ID,
r.PRIM_EMAIL,
r.SEC_EMAIL,
r.PHONE,
r.NAME
from STUDENTS.RECORDS r
inner join STUDENTS.INFO i ON i.ID = r.ID
where I.ROLL_NO = '554';
I think the source of your error query block has incorrect number of result columns is coming from trying to union together a table with 4 columns (id, prim_email, sec_email, phone) with 1 column (name).
From your question, I am gathering that you want a single table of id, prim_email, sec_email, phone from students.records and name from students.info.
I think the following query using CTE's might get you (partially) to your final result. You may want to refactor for optimizing performance.
with s_records as ( select * from students.records ),
s_info as ( select * from students.info ),
joined as (
select
s_records.id,
s_records.prim_email,
s_records.sec_email,
s_records.phone,
s_info.name
from s_records
left join s_info
on s_records.roll_no = s_info.roll_no
where roll_np = '554' )
select * from joined
Overall, I think that a join will be part of your solution rather than a union :-)
I am fairly new to SQL. What I am trying to do is create a view from an existing table. I also need to add a new column to the view which maps to the values of an existing column in the table.
So within the view, if the value in a field for Col_1 = A, then the value in the corresponding row for New_Col = C etc
Does this even make sense? Would I use the CASE clause? Is mapping in this way even possible?
Thanks
The best way to do this is to create a mapping or lookup table
For example consider the following LOOKUP table.
COL_A NEW_VALUE
---- -----
A C
B D
Then you can have a query like this:
SELECT A.*, LOOK.NEW_VALUE
FROM TABLEA AS A
JOIN LOOKUP AS LOOK ON A.COL_A = LOOK.COL_A
This is what DimaSUN is doing in his query too -- but in his case he is creating the table dynamically in the body of the query.
Also note, I'm using a JOIN (which is an inner join) so only results in the lookup table will be returned. This could filter the results. A LEFT JOIN there would return all data from A but some of the new columns might be null.
Generally, a view is an instance of a table/a replica provided that there is no alteration to the original table. So, as per your query you can manipulate the data and columns in a view by using case.
Create View viewname as
Select *,
case when column=a.value then 'C'
....
ELSE
END
FROM ( Select * from table) a
If You have restricted list of replaced values You may hardcode that list in query
select T.*,map.New_Col
from ExistingTable T
left join (
values
('A','C')
,('B','D')
) map (Col_1,New_Col) on map.Col_1 = T.Col_1
In this sample You hardcode 'A' -> 'C' and 'B' -> 'D'
In general case You better may to use additional table ( see Hogan answer )
CREATE VIEW ALL_TABLES AS SELECT * FROM employee_view, av_pay;
I keep getting error message how do I overcome this
VIEW Duplicate column name 'ISLAND'
av_pay:
employee_view:
You are doing a select *, which will output the same column names as defined in the tables you are querying. As you have both columns defined with the same name in both, there you have the error.
So either rename one of the columns or change the query to something like:
select employee_view.ISLAND ISLAND_V, av_pay.ISLAND ISLAND_P, ... FROM ...
The db engine complaints because your select clause is "*" and both the source tables contain the column "island". As a result, the dbms does not know which column should be returned - from employee_view or av_pay?
BTW, a select from 2 tables without a join will result in a cartesian product...
How would the SQL statement look like to return the bottom result from the upper table?
The last letter from the key should be removed. It stands for the language. EXP column should be split into 5 columns with the language prefix and the right value.
I'm weak at writing more or less difficult SQL statements so any help would be appreciated!
The Microsoft Access equivalent of a PIVOT in SQL Server is known as a CROSSTAB. The following query will work for Microsoft Access 2010.
TRANSFORM First(table1.Exp) AS FirstOfEXP
SELECT Left([KEY],Len([KEY])-2) AS [XKEY]
FROM table1
GROUP BY Left([KEY],Len([KEY])-2)
PIVOT Right([KEY],1);
Access will throw a circular field reference error if you try to name the row heading with KEY since that is also the name of the original table field that you are deriving it from. If you do not want XKEY as the field name, then you would need to break apart the above query into two separate queries as shown below:
qsel_table1:
SELECT Left([KEY],Len([KEY])-2) AS XKEY
, Right([KEY],1) AS [Language]
, Table1.Exp
FROM Table1
ORDER BY Left([KEY],Len([KEY])-2), Right([KEY],1);
qsel_table1_Crosstab:
TRANSFORM First(qsel_table1.Exp) AS FirstOfEXP
SELECT qsel_table1.XKEY AS [KEY]
FROM qsel_table1
GROUP BY qsel_table1.XKEY
PIVOT qsel_table1.Language;
In order to always output all language columns regardless of whether there is a value or not, you need to spike of those values into a separate table. That table will then supply the row and column values for the crosstab and the original table will supply the value expression. Using the two query solution above we would instead need to do the following:
table2:
This is a new table with a BASE_KEY TEXT*255 column and a LANG TEXT*1 column. Together these two columns will define the primary key. Populate this table with the following rows:
"AbstractItemNumberReportController.SelectPositionen", "D"
"AbstractItemNumberReportController.SelectPositionen", "E"
"AbstractItemNumberReportController.SelectPositionen", "F"
"AbstractItemNumberReportController.SelectPositionen", "I"
"AbstractItemNumberReportController.SelectPositionen", "X"
qsel_table1:
This query remains unchanged.
qsel_table1_crosstab:
The new table2 is added to this query with an outer join with the original table1. The outer join will allow all rows to be returned from table2 regardless of whether there is a matching row in the table1. Table2 now supplies the values for the row and column headings.
TRANSFORM First(qsel_table1.Exp) AS FirstOfEXP
SELECT Table2.Base_KEY AS [KEY]
FROM Table2 LEFT JOIN qsel_table1 ON (Table2.BASE_KEY = qsel_table1.XKEY)
AND (Table2.LANG = qsel_table1.Language)
GROUP BY Table2.Base_KEY
PIVOT Table2.LANG;
Try something like this:
select *
from
(
select 'abcd' as [key], right([key], 1) as id, expression
from table1
) x
pivot
(
max(expression)
for id in ([D], [E])
) p
Demo Fiddle