Mysql – Hibernate: update to sum from other table

hibernatehqlMySQLsql

I'm trying to replicate this query from MySQL to HQL:
UPDATE users u, mines m SET u.mana = u.mana + COALESCE((SELECT SUM(m.mana_rate) FROM mines m WHERE m.user_id = u.id), 0)

Simply doing this in HQL:
update User u set u.mana = u.mana + (select coalesce(sum(m.manaRate), 0) from Mine m where m.userId = u.id)

Gives following error:
Exception in thread "main" org.hibernate.hql.ast.QuerySyntaxException: unexpected AST node: query [update mm.user.User u set u.mana = u.mana + (select coalesce(sum(m.manaRate), 0) from mm.map.buildings.mines.Mine m where m.userId = u.id)]

I'm new to Hibernate, so I don't really know where to start, and what the error means.
If it's not possible, can i write a native MySQL query in Hibernate?

EDIT: The problem seems to be in "u.mana = u.mana +", because when I just do u.mana = (select… the query works just fine

Best Answer

you can write native queries in hibernate, more about that here. bit sure what is wrong with your query though.

Syntax:

ALTER TABLE {TABLENAME} 
ADD {COLUMNNAME} {TYPE} {NULL|NOT NULL} 
CONSTRAINT {CONSTRAINT_NAME} DEFAULT {DEFAULT_VALUE}
WITH VALUES

Example:

ALTER TABLE SomeTable
        ADD SomeCol Bit NULL --Or NOT NULL.
 CONSTRAINT D_SomeTable_SomeCol --When Omitted a Default-Constraint Name is autogenerated.
    DEFAULT (0)--Optional Default-Constraint.
WITH VALUES --Add if Column is Nullable and you want the Default Value for Existing Records.

Notes:

Optional Constraint Name:
If you leave out CONSTRAINT D_SomeTable_SomeCol then SQL Server will autogenerate
a Default-Contraint with a funny Name like: DF__SomeTa__SomeC__4FB7FEF6

Optional With-Values Statement:
The WITH VALUES is only needed when your Column is Nullable
and you want the Default Value used for Existing Records.
If your Column is NOT NULL, then it will automatically use the Default Value
for all Existing Records, whether you specify WITH VALUES or not.

How Inserts work with a Default-Constraint:
If you insert a Record into SomeTable and do not Specify SomeCol's value, then it will Default to 0.
If you insert a Record and Specify SomeCol's value as NULL (and your column allows nulls),
then the Default-Constraint will not be used and NULL will be inserted as the Value.

Notes were based on everyone's great feedback below.
Special Thanks to:
@Yatrix, @WalterStabosz, @YahooSerious, and @StackMan for their Comments.

MySQL Error 1153 – Got a packet bigger than ‘max_allowed_packet’ bytes

You probably have to change it for both the client (you are running to do the import) AND the daemon mysqld that is running and accepting the import.

For the client, you can specify it on the command line:

mysql --max_allowed_packet=100M -u root -p database < dump.sql

Also, change the my.cnf or my.ini file (usually found in /etc/mysql/) under the mysqld section and set:

max_allowed_packet=100M

or you could run these commands in a MySQL console connected to that same server:

set global net_buffer_length=1000000; 
set global max_allowed_packet=1000000000;

(Use a very large value for the packet size.)

Best Answer

Related Solutions

Sql – Add a column with a default value to an existing table in SQL Server

Syntax:

Example:

Notes:

MySQL Error 1153 – Got a packet bigger than ‘max_allowed_packet’ bytes

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