Why postgresql encount duplicate key when key not exists? - postgresql

When I am inserting data into Postgresql(9.6),throw this error:
ERROR: duplicate key value violates unique constraint "book_intial_name_isbn_isbn10_key"
DETAIL: Key (name, isbn, isbn10)=(三銃士, , ) already exists.
SQL state: 23505
I add uniq constraint on columns name, isbn, isbn10.But when I check the distination table,it does not contains the record:
select * from public.book where name like '%三銃%';
How to fix?This is my insert sql:
insert into public.book
select *
from public.book_backup20190405 legacy
where legacy."name" not in
(
select name
from public.book
)
limit 1000

An educated guess, there may be more than one row in the source table book_backup20190405 which has the unique key tuple ('三銃', '', '').
Since the bulk INSERT INTO ... SELECT ... will be be transactional, you'll be none the wiser to the error, since all data will have been rolled back when the constraint fails.
You can verify this by running a dupe check on the source table:
SELECT name, isbn, isbn10, COUNT(*)
FROM public.book_backup20190405
WHERE name = '三銃'
GROUP BY name, isbn, isbn10
HAVING COUNT(*) > 1;
To see if there are duplicates.
Here's an example of how the source table can be the sole source of duplicates:
http://sqlfiddle.com/#!17/29ba3

Related

Computed table column with MAX value between rows containing a shared value

I have the following table
CREATE TABLE T2
( ID_T2 integer NOT NULL PRIMARY KEY,
FK_T1 integer, <--- foreign key to T1(Table1)
FK_DATE date, <--- foreign key to T1(Table1)
T2_DATE date, <--- user input field
T2_MAX_DIFF COMPUTED BY ( (SELECT DATEDIFF (day, MAX(T2_DATE), CURRENT_DATE) FROM T2 GROUP BY FK_T1) )
);
I want T2_MAX_DIFF to display the number of days since last input across all similar entries with a common FK_T1.
It does work, but if another FK_T1 values is added to the table, I'm getting an error about "multiple rows in singleton select".
I'm assuming that I need some sort of WHERE FK_T1 = FK_T1 of corresponding row. Is it possible to add this? I'm using Firebird 3.0.7 with flamerobin.
The error "multiple rows in singleton select" means that a query that should provide a single scalar value produced multiple rows. And that is not unexpected for a query with GROUP BY FK_T1, as it will produce a row per FK_T1 value.
To fix this, you need to use a correlated sub-query by doing the following:
Alias the table in the subquery to disambiguate it from the table itself
Add a where clause, making sure to use the aliased table (e.g. src, and src.FK_T1), and explicitly reference the table itself for the other side of the comparison (e.g. T2.FK_T1)
(optional) remove the GROUP BY clause because it is not necessary given the WHERE clause. However, leaving the GROUP BY in place may uncover certain types of errors.
The resulting subquery then becomes:
(SELECT DATEDIFF (day, MAX(src.T2_DATE), CURRENT_DATE)
FROM T2 src
WHERE src.FK_T1 = T2.FK_T1
GROUP BY src.FK_T1)
Notice the alias src for the table referenced in the subquery, the use of src.FK_T1 in the condition, and the explicit use of the table in T2.FK_T1 to reference the column of the current row of the table itself. If you'd use src.FK_T1 = FK_T1, it would compare with the FK_T1 column of src (as if you'd used src.FK_T1 = src.FK_T2), so that would always be true.
CREATE TABLE T2
( ID_T2 integer NOT NULL PRIMARY KEY,
FK_T1 integer,
FK_DATE date,
T2_DATE date,
T2_MAX_DIFF COMPUTED BY ( (
SELECT DATEDIFF (day, MAX(src.T2_DATE), CURRENT_DATE)
FROM T2 src
WHERE src.FK_T1 = T2.FK_T1
GROUP BY src.FK_T1) )
);

Mybatis Insert PK manually

I am trying to single insert data into table with assigned PK. Manually assiging PK.
XML file
<insert id = "insertStd" parameterType = "com.org.springboot.dao.StudentEntity" useGeneratedKeys = "false" keyProperty = "insertStd.id", keyColumn = "id">
INSERT INTO STUDENT (ID, NAME, BRANCH, PERCENTAGE, PHONE, EMAIL )
VALUES (ID=#{insertStd.id}, NAME=#{insertStd.name}, BRANCH=#{insertStd.branch}, PERCENTAGE=#{insertStd.percentage}, PHONE=#{insertStd.phone}, EMAIL =#{insertStd.email});
</insert>
Service call method
public boolean saveStudent(Student student){
LOGGER.info("Student object save");
int savedId= studentMapper.insertStd(student);
}
Log file
org.springframework.jdbc.badsqlgrammarexception
### Error updating database Causes: cause org.postgresql.util.psqlexception error column id does not exist
HINT: There is a column named "id" in the table "student" but it can't be referenced from this part of the query.
Position 200
### Error may exist in file [c:\.....\StudentMapper.xml]
### Error may involve in com.org.springboot.dao.StudentMapper.insertStd-InLine
### The error occurred while setting parameters
### SQL INSERT INTO STUDENT (ID, NAME, BRANCH, PERCENTAGE, PHONE, EMAIL )
VALUES (ID=?, NAME=?,BRANCH=?, PERCENTAGE=?, PHONE=?, EMAIL=?);
### cause org.postgresql.util.psqlexception ERROR column "id" doesn't exist. //It did worked with JPA id assigned manually.
### There is a column named "ID" in the table "STUDENT", Bbut it cannot be referenced from the part of the query.
The INSERT statement of malformed. The VALUES clause should not include the column names.
Also, since there's no primary auto-generation, you can remove all the other attributes. Just leave the mapper id.
Note: if you want to manually assign the PK value, you need to make sure the table does not have a GENERATED ALWAYS clause for the column. If this is the case, the table will ignore the value you are providing and will use its own rules to generate the PK.
Use:
<insert id="insertStd">
INSERT INTO STUDENT (ID, NAME, BRANCH, PERCENTAGE, PHONE, EMAIL)
VALUES (
#{insertStd.id}, #{insertStd.name}, #{insertStd.branch},
#{insertStd.percentage}, #{insertStd.phone}, #{insertStd.email}
);
</insert>
Your error is easily reproduceable:
create table t (a int, b varchar(10));
insert into t (a, b) values (123, 'ABC'); -- succeeds
insert into t (a, b) values (a=123, b='ABC'); -- fails!
error: column "a" does not exist
See the Fiddle.

I'm trying to insert tuples into a table A (from table B) if the primary key of the table B tuple doesn't exist in tuple A

Here is what I have so far:
INSERT INTO Tenants (LeaseStartDate, LeaseExpirationDate, Rent, LeaseTenantSSN, RentOverdue)
SELECT CURRENT_DATE, NULL, NewRentPayments.Rent, NewRentPayments.LeaseTenantSSN, FALSE from NewRentPayments
WHERE NOT EXISTS (SELECT * FROM Tenants, NewRentPayments WHERE NewRentPayments.HouseID = Tenants.HouseID AND
NewRentPayments.ApartmentNumber = Tenants.ApartmentNumber)
So, HouseID and ApartmentNumber together make up the primary key. If there is a tuple in table B (NewRentPayments) that doesn't exist in table A (Tenants) based on the primary key, then it needs to be inserted into Tenants.
The problem is, when I run my query, it doesn't insert anything (I know for a fact there should be 1 tuple inserted). I'm at a loss, because it looks like it should work.
Thanks.
Your subquery was not correlated - It was just a non-correlated join query.
As per description of your problem, you don't need this join.
Try this:
insert into Tenants (LeaseStartDate, LeaseExpirationDate, Rent, LeaseTenantSSN, RentOverdue)
select current_date, null, p.Rent, p.LeaseTenantSSN, FALSE
from NewRentPayments p
where not exists (
select *
from Tenants t
where p.HouseID = t.HouseID
and p.ApartmentNumber = t.ApartmentNumber
)

Insert multiple rows where not exists PostgresQL

I'd like to generate a single sql query to mass-insert a series of rows that don't exist on a table. My current setup makes a new query for each record insertion similar to the solution detailed in WHERE NOT EXISTS in PostgreSQL gives syntax error, but I'd like to move this to a single query to optimize performance since my current setup could generate several hundred queries at a time. Right now I'm trying something like the example I've added below:
INSERT INTO users (first_name, last_name, uid)
SELECT ( 'John', 'Doe', '3sldkjfksjd'), ( 'Jane', 'Doe', 'adslkejkdsjfds')
WHERE NOT EXISTS (
SELECT * FROM users WHERE uid IN ('3sldkjfksjd', 'adslkejkdsjfds')
)
Postgres returns the following error:
PG::Error: ERROR: INSERT has more target columns than expressions
The problem is that PostgresQL doesn't seem to want to take a series of values when using SELECT. Conversely, I can make the insertions using VALUES, but I can't then prevent duplicates from being generated using WHERE NOT EXISTS.
http://www.techonthenet.com/postgresql/insert.php suggests in the section EXAMPLE - USING SUB-SELECT that multiple records should be insertable from another referenced table using SELECT, so I'm wondering why I can't seem to pass in a series of values to insert. The values I'm passing are coming from an external API, so I need to generate the values to insert by hand.
Your select is not doing what you think it does.
The most compact version in PostgreSQL would be something like this:
with data(first_name, last_name, uid) as (
values
( 'John', 'Doe', '3sldkjfksjd'),
( 'Jane', 'Doe', 'adslkejkdsjfds')
)
insert into users (first_name, last_name, uid)
select d.first_name, d.last_name, d.uid
from data d
where not exists (select 1
from users u2
where u2.uid = d.uid);
Which is pretty much equivalent to:
insert into users (first_name, last_name, uid)
select d.first_name, d.last_name, d.uid
from (
select 'John' as first_name, 'Doe' as last_name, '3sldkjfksjd' as uid
union all
select 'Jane', 'Doe', 'adslkejkdsjfds'
) as d
where not exists (select 1
from users u2
where u2.uid = d.uid);
a_horse_with_no_name's answer actually has a syntax error, missing a final closing right parens, but other than that is the correct way to do this.
Update:
For anyone coming to this with a situation like mine, if you have columns that need to be type cast (for instance timestamps or uuids or jsonb in PG 9.5), you must declare that in the values you pass to the query:
-- insert multiple if not exists
-- where another_column_name is of type uuid, with strings cast as uuids
-- where created_at and updated_at is of type timestamp, with strings cast as timestamps
WITH data (id, some_column_name, another_column_name, created_at, updated_at) AS (
VALUES
(<id value>, <some_column_name_value>, 'a5fa7660-8273-4ffd-b832-d94f081a4661'::uuid, '2016-06-13T12:15:27.552-07:00'::timestamp, '2016-06-13T12:15:27.879-07:00'::timestamp),
(<id value>, <some_column_name_value>, 'b9b17117-1e90-45c5-8f62-d03412d407dd'::uuid, '2016-06-13T12:08:17.683-07:00'::timestamp, '2016-06-13T12:08:17.801-07:00'::timestamp)
)
INSERT INTO table_name (id, some_column_name, another_column_name, created_at, updated_at)
SELECT d.id, d.survey_id, d.arrival_uuid, d.gf_created_at, d.gf_updated_at
FROM data d
WHERE NOT EXISTS (SELECT 1 FROM table_name t WHERE t.id = d.id);
a_horse_with_no_name's answer saved me today on a project, but had to make these tweaks to make it perfect.

In DB2, perform an update based on insert for large number of rows

In DB2, I need to do an insert, then, using results/data from that insert, update a related table. I need to do it on a million plus records and would prefer not to lock the entire database. So, 1) how do I 'couple' the insert and update statements? 2) how can I ensure the integrity of the transaction (without locking the whole she-bang)?
some pseudo-code should help clarify
STEP 1
insert into table1 (neededId, id) select DYNAMICVALUE, id from tableX where needed value is null
STEP 2
update table2 set neededId = (GET THE DYNAMIC VALUE JUST INSERTED) where id = (THE ID JUST INSERTED)
note: in table1, the ID col is not unique, so i can't just filter on that to find the new DYNAMICVALUE
This should be more clear (FTR, this works, but I don't like it, because I'd have to lock the tables to maintain integrity. Would be great it I could run these statements together, and allow the update to refer to the newAddressNumber value.)
/****RUNNING TOP INSERT FIRST****/*
--insert a new address for each order that does not have a address id
insert into addresses
(customerId, addressNumber, address)
select
cust.Id,
--get next available addressNumber
ifNull((select max(addy2.addressNumber) from addresses addy2 where addy2.customerId = cust.id),0) + 1 as newAddressNumber,
cust.address
from customers cust
where exists (
--find all customers with at least 1 order where addressNumber is null
select 1 from orders ord
where 1=1
and ord.customerId = cust.id
and ord.addressNumber is null
)
/*****RUNNING THIS UPDATE SECOND*****/
update orders ord1
set addressNumber = (
select max(addressNumber) from addresses addy3
where addy3.customerId = ord1.customerId
)
where 1=1
and ord1.addressNumber is null
The IDENTITY_VAL_LOCAL function is a non-deterministic function that returns the most recently assigned value for an identity column, where the assignment occurred as a result of a single INSERT statement using a VALUES clause