Postgresql Multiple insertions into any tables depending on result of one select - postgresql

Using Postgresql (9.6) i need to execute multiple insert queries into any tables (table1, table2, table3, ...) depending on result of one select query from another tableMain if result has one or more records, like:
{
insert into table1 (id, name) values(1, 'name');
insert into table2 (id, name) values(1, 'name');
insert into table3 (id, name) values(1, 'name');
} if exists (select id from tableMain where id = 1)

You can use a data modifying CTE that first checks if the row in tablemain exists, and then re-uses that result in subsequent INSERT statements.
with idcheck (main_exist) as (
select exists (select * from tablemain where id = 1 limit 1)
), t1 as (
insert into table1 (id, name)
select 1, 'name'
from idcheck
where main_exists
), t2 as (
insert into table2 (id, name)
select 1, 'name'
from idcheck
where main_exists
)
insert into table3 (id, name)
select 1, 'name'
from idcheck
where main_exists;
If you always want to insert the same values in all three tables, you can include those values in the first query so that you don't need to repeat them:
with idcheck (id, name, main_exist) as (
select 1,
'name',
exists (select * from tablemain where id = 1 limit 1)
), t1 as (
insert into table1 (id, name)
select id, name
from idcheck
where main_exists
), t2 as (
insert into table2 (id, name)
select id, name
from idcheck
where main_exists
)
insert into table3 (id, name)
select id, name
from idcheck
where main_exists;

Related

Generate multiple rows for single column

I've data as below:
Create table #student(id int, name varchar(20))
create table #test(id int, test_Date datetime, test_type varchar(20))
Insert int #student values (1, 'A')
insert into #student values (2, 'B')
insert into #student values (3, 'C')
insert into #test values (1, '1/1/2022', 'Math')
insert into #test values (1, '1/2/2022', 'Eng')
insert into #test values (1, '1/3/2022', 'Science')
insert into #test values (2, '2/1/2022', 'Math')
insert into #test values (2, '2/2/2022', 'Eng')
insert into #test values (3, '3/1/2022', 'Math')
insert into #test values (3, '3/2/2022', 'Science')
Need data in the below format:
Output
Looks like you simply just want to join your #student table to your #test table.
SELECT s.id, s.name, t.test_date. t.test_type
FROM #student s
JOIN #test t
ON s.id = t.id
ORDER BY s.id, t.test_date, t.test_type
This will show the id, name, test date and test type per student.
Ordered by the student id, test date and test type.
try this
;with t0 AS (
SELECT s.id, s.name, t.test_date, t.test_type
,dense_rank() over(partition by s.id order by s.id ,test_date) AS drid
,dense_rank() over(partition by s.id,name order by s.id ,test_date) AS drname
FROM #student s
JOIN #test t
ON s.id = t.id
)
select case drid when 1 then id else null end as id
,case drname when 1 then name else null end as
name,test_Date,test_type from t0
ORDER BY t0.id, t0.name

Recursive CTE and multiple inserts in joined table

I'm searching to copy nodes of a hierarchical tree and to apply the changes onto a joined table. I found parts of the answer in other questions like Postgresql copy data within the tree table for the tree copy (in my case I only copy the children and not the root) and PostgreSQL - Insert data into multiple tables simultaneously to insert data in several table simultaneously, but I don't manage to mix them.
I would like to:
Generate the new nodes id from the fields table
Insert the new field ids in the data_versions table
Insert the new nodes in the fields table with the data_id from the data_versions table
Note: there is a circular reference between the fields and the data_versions tables.
See below the schema:
Here is a working query, but without the insert in the data_versions table. It is only a shallow copy (keeping the same data_id) while I would like a deep copy:
WITH created_data AS (
WITH RECURSIVE cte AS (
SELECT *, nextval('fields_id_seq') new_id FROM fields WHERE parent_id = :source_field_id
UNION ALL
SELECT fields.*, nextval('fields_id_seq') new_id FROM cte JOIN fields ON cte.id = fields.parent_id
)
SELECT C1.new_id, C1.name, C1.field_type, C1.data_id, C2.new_id new_parent_id
FROM cte C1 LEFT JOIN cte C2 ON C1.parent_id = C2.id
)
INSERT INTO fields (id, name, parent_id, field_type, data_id)
SELECT new_id, name, COALESCE(new_parent_id, :target_field_id), field_type, data_id FROM created_data
RETURNING id, name, parent_id, field_type, data_id;
And here is the draft query I'm working on for inserting data in the data_versions table resulting with WITH clause containing a data-modifying statement must be at the top level as an error:
WITH created_data AS (
WITH cloned_fields AS (
WITH RECURSIVE cte AS (
SELECT *, nextval('fields_id_seq') new_id FROM fields WHERE parent_id = :source_field_id
UNION ALL
SELECT fields.*, nextval('fields_id_seq') new_id FROM cte JOIN fields ON cte.id = fields.parent_id
)
SELECT C1.new_id, C1.name, C1.field_type, C1.data_id, C2.new_id new_parent_id
FROM cte C1 LEFT JOIN cte C2 ON C1.parent_id = C2.id
),
cloned_data AS (
INSERT INTO data_versions (value, author, field_id)
SELECT d.value, d.author, c.new_id
FROM cloned_fields c
INNER JOIN data_versions d ON c.data_id = d.id
RETURNING id data_id
)
SELECT cloned_fields.new_id, cloned_fields.name, cloned_fields.field_type, cloned_fields.new_parent_id, cloned_data.data_id
FROM cloned_fields
INNER JOIN cloned_data ON cloned_fields.data_id = cloned_data.id
)
INSERT INTO fields (id, name, parent_id, field_type, data_id)
SELECT new_id, name, COALESCE(new_parent_id, :target_field_id), field_type, data_id FROM created_data
RETURNING id, name, parent_id, field_type, data_id, value data;
If other people were encountering the same issue as me, I came up with this solution some months later. The trick was to move the data-modifying CTE at the top level as suggested by the error message. We can always access previously declared CTE's:
WITH new_fields_ids AS (
WITH RECURSIVE cte AS (
SELECT *, nextval('fields_id_seq') new_id FROM fields WHERE parent_id = :source_field_id
UNION ALL
SELECT fields.*, nextval('fields_id_seq') new_id FROM cte JOIN fields ON cte.id = fields.parent_id
)
SELECT C1.new_id, C1.name, C1.field_type, C1.data_id, C2.new_id new_parent_id
FROM cte C1 LEFT JOIN cte C2 ON C1.parent_id = C2.id
),
cloned_data AS (
INSERT INTO data_versions (value, author, field_id)
SELECT d.value, d.author, c.new_id
FROM new_fields_ids c
INNER JOIN data_versions d ON c.data_id = d.id
RETURNING id AS data_id, field_id, value
),
created_data AS (
SELECT new_fields_ids.new_id, new_fields_ids.name, new_fields_ids.field_type, new_fields_ids.new_parent_id, cloned_data.data_id
FROM new_fields_ids
INNER JOIN cloned_data ON new_fields_ids.new_id = cloned_data.field_id
),
cloned_fields AS (
INSERT INTO fields (id, name, parent_id, field_type, data_id)
SELECT new_id, name, COALESCE(new_parent_id, :target_field_id), field_type, data_id FROM created_data
RETURNING id, name, parent_id, field_type, data_id
)
SELECT f.id, f.name, f.parent_id, f.field_type, f.data_id, d.value AS data FROM cloned_fields f
INNER JOIN cloned_data d ON f.id = d.field_id;

Recursive hierarchical PGSQL request with uuid goes into a loop

Helle there
I'd like to get a hierarchical data parent / childs. meaning that if i select tje id of the parent, all its chilren will be in the record
Their relations are defined by the parent UUID
I have in a DB the following data :
INSERT INTO dummy_table (Id, parent) VALUES ('0171a28a-578a-49b5-86d5-ff0df54c8e96', '0171a28a-578a-49b5-86d5-ff0df54c8e96')
INSERT INTO dummy_table (Id, parent) VALUES ('0171a28a-5809-4708-9fc9-aeb91c16e560', '0171a28a-578a-49b5-86d5-ff0df54c8e96')
INSERT INTO dummy_table (Id, parent) VALUES ('0171a28a-580b-4de9-b3fa-35f13df27dd5', '0171a28a-5809-4708-9fc9-aeb91c16e560')
INSERT INTO dummy_table (Id, parent) VALUES ('0171a28a-580c-4e6b-8d17-0cc18af24b25', '0171a28a-580b-4de9-b3fa-35f13df27dd5')
INSERT INTO dummy_table (Id, parent) VALUES ('0171a28a-580d-47ee-aa15-92c6727e657e', '0171a28a-580c-4e6b-8d17-0cc18af24b25')
And my request is the following :
WITH RECURSIVE cte AS (
SELECT id, parent FROM dummy_table WHERE id = '0171a28a-578a-49b5-86d5-ff0df54c8e96'
UNION ALL
SELECT dt.id, dt.parent FROM dummy_table dt INNER JOIN cte ON cte.parent = dt.id
)
SELECT * FROM cte;
The problem i have is that it loops and I cannot figure out why.
Any help please ?
Thanks you all
That query goes into a loop because the first row in your data references itself as its parent and so the recursion never stops. Add a check to avoid self-reference and you should be fine
WITH RECURSIVE cte AS (
SELECT id, parent FROM dummy_table WHERE id = '0171a28a-578a-49b5-86d5-ff0df54c8e96'
UNION ALL
SELECT dt.id, dt.parent FROM dummy_table dt INNER JOIN cte ON cte.parent = dt.id and cte.id <> dt.id
)
SELECT * FROM cte;
Another option is setting parent as null in the rows where parent is equal to id

Converting Traditional IF EXIST UPDATE ELSE INSERT into MERGE is not working?

I am going to use MERGE to insert or update a table depending upon ehether it's exist or not. This is my query,
declare #t table
(
id int,
name varchar(10)
)
insert into #t values(1,'a')
MERGE INTO #t t1
USING (SELECT id FROM #t WHERE ID = 2) t2 ON (t1.id = t2.id)
WHEN MATCHED THEN
UPDATE SET name = 'd', id = 3
WHEN NOT MATCHED THEN
INSERT (id, name)
VALUES (2, 'b');
select * from #t;
The result is,
id name
1 a
I think it should be,
id name
1 a
2 b
You have your USING part slightly messed up, that's where to put what you want to match against (although in this case you're only using id)
declare #t table
(
id int,
name varchar(10)
)
insert into #t values(1,'a')
MERGE INTO #t t1
USING (SELECT 2, 'b') AS t2 (id, name) ON (t1.id = t2.id)
WHEN MATCHED THEN
UPDATE SET name = 'd', id = 3
WHEN NOT MATCHED THEN
INSERT (id, name)
VALUES (2, 'b');
select * from #t;
As Mikhail pointed out, your query in the USING clause doesn't contain any rows.
If you want to do an upsert, put the new data into the USING clause:
MERGE INTO #t t1
USING (SELECT 2 as id, 'b' as name) t2 ON (t1.id = t2.id) --This no longer has an artificial dependency on #t
WHEN MATCHED THEN
UPDATE SET name = t2.name
WHEN NOT MATCHED THEN
INSERT (id, name)
VALUES (t2.id, t2.name);
This query won't return anything:
SELECT id FROM #t WHERE ID = 2
Because where is no rows in table with ID = 2, so there is nothing to merge into table.
Besides, in MATCHED clause you are updating a field ID on which you are joining table, i think, it's forbidden.
For each DML operations you have to commit (Marks the end of a successful the transaction)Then only you will be able to see the latest data
For example :
GO
BEGIN TRANSACTION;
GO
DELETE FROM HumanResources.JobCandidate
WHERE JobCandidateID = 13;
GO
COMMIT TRANSACTION;
GO

one column split to more column sql server 2008?

Table name: Table1
id name
1 1-aaa-14 milan road
2 23-abcde-lsd road
3 2-mnbvcx-welcoome street
I want the result like this:
Id name name1 name2
1 1 aaa 14 milan road
2 23 abcde lsd road
3 2 mnbvcx welcoome street
This function ought to give you what you need.
--Drop Function Dbo.Part
Create Function Dbo.Part
(#Value Varchar(8000)
,#Part Int
,#Sep Char(1)='-'
)Returns Varchar(8000)
As Begin
Declare #Start Int
Declare #Finish Int
Set #Start=1
Set #Finish=CharIndex(#Sep,#Value,#Start)
While (#Part>1 And #Finish>0)Begin
Set #Start=#Finish+1
Set #Finish=CharIndex(#Sep,#Value,#Start)
Set #Part=#Part-1
End
If #Part>1 Set #Start=Len(#Value)+1 -- Not found
If #Finish=0 Set #Finish=Len(#Value)+1 -- Last token on line
Return SubString(#Value,#Start,#Finish-#Start)
End
Usage:
Select ID
,Dbo.Part(Name,1,Default)As Name
,Dbo.Part(Name,2,Default)As Name1
,Dbo.Part(Name,3,Default)As Name2
From Dbo.Table1
It's rather compute-intensive, so if Table1 is very long you ought to write the results to another table, which you could refresh from time to time (perhaps once a day, at night).
Better yet, you could create a trigger, which automatically updates Table2 whenever a change is made to Table1. Assuming that column ID is primary key:
Create Table Dbo.Table2(
ID Int Constraint PK_Table2 Primary Key,
Name Varchar(8000),
Name1 Varchar(8000),
Name2 Varchar(8000))
Create Trigger Trigger_Table1 on Dbo.Table1 After Insert,Update,Delete
As Begin
If (Select Count(*)From Deleted)>0
Delete From Dbo.Table2 Where ID=(Select ID From Deleted)
If (Select Count(*)From Inserted)>0
Insert Dbo.Table2(ID, Name, Name1, Name2)
Select ID
,Dbo.Part(Name,1,Default)
,Dbo.Part(Name,2,Default)
,Dbo.Part(Name,3,Default)
From Inserted
End
Now, do your data manipulation (Insert, Update, Delete) on Table1, but do your Select statements on Table2 instead.
The below solution uses a recursive CTE for splitting the strings, and PIVOT for displaying the parts in their own columns.
WITH Table1 (id, name) AS (
SELECT 1, '1-aaa-14 milan road' UNION ALL
SELECT 2, '23-abcde-lsd road' UNION ALL
SELECT 3, '2-mnbvcx-welcoome street'
),
cutpositions AS (
SELECT
id, name,
rownum = 1,
startpos = 1,
nextdash = CHARINDEX('-', name + '-')
FROM Table1
UNION ALL
SELECT
id, name,
rownum + 1,
nextdash + 1,
CHARINDEX('-', name + '-', nextdash + 1)
FROM cutpositions c
WHERE nextdash < LEN(name)
)
SELECT
id,
[1] AS name,
[2] AS name1,
[3] AS name2
/* add more columns here */
FROM (
SELECT
id, rownum,
part = SUBSTRING(name, startpos, nextdash - startpos)
FROM cutpositions
) s
PIVOT ( MAX(part) FOR rownum IN ([1], [2], [3] /* extend the list here */) ) x
Without additional modifications this query can split names consisting of up to 100 parts (that's the default maximum recursion depth, which can be changed), but can only display no more than 3 of them. You can easily extend it to however many parts you want it to display, just follow the instructions in the comments.
select T.id,
substring(T.Name, 1, D1.Pos-1) as Name,
substring(T.Name, D1.Pos+1, D2.Pos-D1.Pos-1) as Name1,
substring(T.Name, D2.Pos+1, len(T.name)) as Name2
from Table1 as T
cross apply (select charindex('-', T.Name, 1)) as D1(Pos)
cross apply (select charindex('-', T.Name, D1.Pos+1)) as D2(Pos)
Testing performance of suggested solutions
Setup:
create table Table1
(
id int identity primary key,
Name varchar(50)
)
go
insert into Table1
select '1-aaa-14 milan road' union all
select '23-abcde-lsd road' union all
select '2-mnbvcx-welcoome street'
go 10000
Result:
if you always will have 2 dashes, you can do the following by using PARSENAME
--testing table
CREATE TABLE #test(id INT, NAME VARCHAR(1000))
INSERT #test VALUES(1, '1-aaa-14 milan road')
INSERT #test VALUES(2, '23-abcde-lsd road')
INSERT #test VALUES(3, '2-mnbvcx-welcoome street')
SELECT id,PARSENAME(name,3) AS name,
PARSENAME(name,2) AS name1,
PARSENAME(name,1)AS name2
FROM (
SELECT id,REPLACE(NAME,'-','.') NAME
FROM #test)x
if you have dots in the name column you have to first replace them and then replace them back to dots in the end
example, by using a tilde to substitute the dot
INSERT #test VALUES(3, '5-mnbvcx-welcoome street.')
SELECT id,REPLACE(PARSENAME(name,3),'~','.') AS name,
REPLACE(PARSENAME(name,2),'~','.') AS name1,
REPLACE(PARSENAME(name,1),'~','.') AS name2
FROM (
SELECT id,REPLACE(REPLACE(NAME,'.','~'),'-','.') NAME
FROM #test)x