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How can I access a value when inserting into a table?

I'm trying to write a java sql query, the simplified table would be table(name,version) with a unique constraint on (name, version).
I'm trying to insert a row into my database with a conditional statement. Meaning that when a entry with the same name exists, it should insert the row with same name and its version increased by 1.
I have tried with the following:
INSERT INTO table(name,version)
VALUES(?, CASE WHEN EXISTS(SELECT name from table where name=?)
THEN (SELECT MAX(version) FROM table WHERE name = ?) +1
ELSE 1 END)
values are sent by user.
My question is, how can I access the 'name' inside the values so I could compare them?

If you want to write this as a single query:
INSERT INTO table (name, version)
SELECT ?, COLAESCE(MAX(t2.version) + 1, 1)
FROM table t2
WHERE t2.name = ?;
That said, this is dangerous. Two threads could execute this query "at the same time" and possibly create the same version number. You can prevent this from happening by adding a unique index/constraint on (name, version).
With the unique index/constraint, one of the updates will fail if there is a conflict.

I see at least two approaches:
1. For each pair of name and version you first query the max version:
SELECT MAX(VERSION) as MAX FROM <table> WHERE NAME = <name>
And then you insert the result + 1 with a corresponding insert query:
INSERT INTO <table>(NAME,VERSION) VALUES (<name>,result+1)
This approach is very straight-forward, easy-to-read and implement, however, not really performant because of so many queries necessary.
You can achieve that with sql alone with sql analytics and window functions, e.g.:
SELECT NAME, ROW_NUMBER() over (partition BY NAME ORDER BY NAME) as VERSION FROM<table>
You can then save the result of this query as a table using CREATE TABLE as SELECT...
(The assumption here is that the first version is 1, if it is not the case, then one could slightly rework the query). This solution would be very performant even for large datasets.

You should get the name before insertion. In your case, if something went wrong then how would you know about it so you get the name before insert query.
Not sure but you try this:
declare int version;
if exists(SELECT name from table where name=?)
then
version = SELECT MAX(version) FROM table WHERE name = ?
version += 1
else
version = 1
end
Regards.

This is actually a bad plan, you might be changing what the user's specified data. That is likely to not be what is desired, maybe they're not trying to create a new version but just unaware that the one wanted already exists. But, you can create a function, which your java calls, not only inserts the requested version or max+1 if the requested version already exists. Moreover it returns the actual values inserted.
-- create table
create table nv( name text
, version integer
, constraint nv_uk unique (name, version)
);
-- function to create version or 1+max if requested exists
create or replace function new_version
( name_in text
, version_in integer
)
returns record
language plpgsql strict
as $$
declare
violated_constraint text;
return_name_version record;
begin
insert into nv(name,version)
values (name_in,version_in)
returning (name, version) into return_name_version;
return return_name_version;
exception
when unique_violation
then
GET STACKED DIAGNOSTICS violated_constraint = CONSTRAINT_NAME;
if violated_constraint like '%nv\_uk%'
then
insert into nv(name,version)
select name_in, 1+max(version)
from nv
where name = name_in
group by name_in
returning (name, version) into return_name_version;
return return_name_version;
end if;
end;
$$;
-- create some data
insert into nv(name,version)
select 'n1', gn
from generate_series( 1,3) gn ;
-- test insert existing
select new_version('n2',1);
select new_version('n1',1);
select *
from nv
order by name, version;

java8 + mariadb 5.6: How to get autogenerated value when insert a blob

I have a mariadb table with 2 cols: rowid int pk autogenerated and imagen blob.
By using "CallableStatement sentence = mariaConn.prepareCall(myinsert);" I'm able to add a new row with a blob into "imagen" BUT I can't get the autogenerated pk col "rowid".
By the other hand, using "Statement sentence = mariaConn.prepareStatement(myinsert);" I can get the autogenerated col "rowid" but I can't add a blob into "imagen" (only do if it is empty).
Is there a way to do both things at one call? (trying to avoid a Statement insert to get the pk and then a CallableStatement to update the blob).
Note: in Oracle is pretty simple using CallableStatement because Oracle's insert has a "returning" clause <= I'm trying to emulate it on mariadb.
Thanks in advance.

you do not need CallableStatement to insert blob, a simple prepared statement
insert into table(imagen) values(?)
works,and with that you can get autogenerated value if you use Statement.RETURN_GENERATED_KEYS during preparation, and Statement.getGeneratedKeys() after execution. You also can do
select last_insert_id()
any time, but this is less efficient.
There is no MariaDB 5.6 btw.

Fire Sequence.nextval query using jdbctemplate in spring

Database : Oracle
I have table in which there are 10 columns and i want sequence next value when insert row and also use that sequence number which inserted.
Now i have searched and find that KeyHolder of spring is useful but restrict for only less than 8 field so i can't use that.
How can i fire "select MySequence.nextval from dual" query and get sequence using jdbctemplate(NamedParameterJDBCTemplate) ?
Is other way to achieve for get inserted sequence value ?.

Using a jdbctemplate you can just mention the sequence generator as a value, e.g.
jdbcTemplate.update("INSERT INTO TABLE (id, data) VALUES (MySequence.nextval, ?)", new Object[] { data });
A note regarding the sequence generation: for versions before Oracle 12c you should have a trigger which will increment the sequence for you. From 12c you can use the auto-increment feature.

You can achieve this by using JdbcTemplate like this :
final SqlRowSet sqlRowSet = jdbcTemplate.queryForRowSet(NEXT_VALUE_QUERY);
sqlRowSet.next();// mandatory to move the cursor
sqlRowSet.getLong(1);// the value of the nextval

How can I get an id for a new record in a generic way? (JOOQ 3.4 with Postgres)

With jooq 3.4 I can't figure out how to do this (with Postgresql):
Query query = dsl.insertInto(TABLE)
.set(TABLE.ID, Sequences.TABLE_ID_SEQ.nextval());
but in a case when I don't know which is the exact table, something like this:
TableImpl<?> tableImpl;
Query query = dsl.insertInto(tableImpl)
.set(tableImpl.getIdentity(), tableImpl.getIdentity().getSequence().nextval());
Is it somehow possible?
I tried this:
dsl.insertInto(tableImpl)
.set(DSL.field("id"),
tableImpl.getSchema().getSequence("table_id_seq").nextval())
This works but I still don't know how to get the sequence name from the TableImpl object.
Is there a solution for this? Or is there a problem with my approach?
In plain SQL I would do this:
insert into table_A (id) VALUES nextval('table_A_id_seq');
insert into table_B (table_A_id, some_val) VALUES (currval('table_A_id_seq'), some_val);
So I need the value or a reference to that id for later use of the id that was generated for the inserted record as default, but I don't want to set any other values.

jOOQ currently doesn't have any means of associating a table with its implicitly used sequence for the identity column. The reason for this is that the sequence is generated when the table is created, but it isn't formally connected to that table.
Usually, you don't have to explicitly set the serial value of a column in a PostgreSQL database. It is generated automatically on insert. In terms of DDL, this means:
CREATE TABLE tablename (
colname SERIAL
);
is equivalent to specifying:
CREATE SEQUENCE tablename_colname_seq;
CREATE TABLE tablename (
colname integer NOT NULL DEFAULT nextval('tablename_colname_seq')
);
ALTER SEQUENCE tablename_colname_seq OWNED BY tablename.colname;
The above is taken from:
http://www.postgresql.org/docs/9.3/static/datatype-numeric.html#DATATYPE-SERIAL
In other words, just leave out the ID values from the INSERT statements.
"Empty" INSERT statements
Note that if you want to create an "empty" INSERT statement, i.e. a statement where you pass no values at all, generating a new column with a generated ID, you can use the DEFAULT VALUES clause.
With SQL
INSERT INTO tablename DEFAULT VALUES
With jOOQ
DSL.using(configuration)
.insertInto(TABLENAME)
.defaultValues()
.execute();
Returning IDs
Note that PostgreSQL has native support for an INSERT .. RETURNING clause, which is also supported by jOOQ:
With SQL
INSERT INTO tablename (...) VALUES (...) RETURNING ID
With jOOQ
DSL.using(configuration)
.insertInto(TABLENAME, ...)
.values(...)
.returning(TABLENAME.ID)
.fetchOne();

How to get the serial id just after inserting a row? [duplicate]

This question already has answers here:
How to get a value from the last inserted row? [duplicate]
(14 answers)
Closed 9 years ago.
I have a table with row 'id' (a primary key) default set to serial in PostgreSQL. I insert into this row by calling
session.getCurrentSession().createSQLQuery("some insert query")
without adding any value into id as it is default set to serial.
How can I retrieve the `id' of just inserted row?

JDBC statements can return the generated keys. For instance, if the table has a single column id of type serial (probably PK) that is not mentioned in the insert SQL below, the generated value for this column can be obtained as:
PreparedStatement s = connection.createStatement
("INSERT INTO my_table (c,d) VALUES (1,2)",
Statement.RETURN_GENERATED_KEYS);
s.executeUpdate();
ResultSet keys = s.getGeneratedKeys();
int id = keys.getInt(1);
This is faster than sending the second query to obtain the sequence value or max column value later. Also depending on circumstances these two other solutions may not be not be thread safe.

Since it is serial you can use select max(id) from tableName
Using max(id) is a very bad idea. It will not give you the correct result
in case of multiple concurrent transactions. The only correct way is to use
curval() or the returning clause.
In posgresql: There is already a stackoverflow-question exists BTW.
`INSERT INTO tableName(id, name) VALUES(DEFAULT, 'bob') RETURNING id;`
(also)
Get a specific sequence:
SELECT currval('name_of_your_sequence');
Get the last value from the last sequence used:
SELECT lastval();
Manual: http://www.postgresql.org/docs/current/static/functions-sequence.html
For PHP-mysql users:
From php.net clickhere
<?php
$link = mysqli_connect('localhost', 'mysql_user', 'mysql_password');
if (!$link) {
die('Could not connect: ' . mysqli::$connect_error() );
}
mysqli::select_db('mydb');
mysqli::query("INSERT INTO mytable (product) values ('kossu')");
printf("Last inserted record has id %d\n", mysqli::$insert_id());
?>
But you need to connect for every query.

use SELECT CURRVAL(); . Typically used in conjunction with pg_get_serial_sequence
postgreSQL function for last inserted ID