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Postgres: How to do Composite keys?
...already implied), too:
CREATE TABLE tags
(
question_id INTEGER NOT NULL,
tag_id SERIAL NOT NULL,
tag1 VARCHAR(20),
tag2 VARCHAR(20),
tag3 VARCHAR(20),
PRIMARY KEY(question_id, tag_id)
);
NOTICE: ...
jQuery: select all elements of a given class, except for a particular Id
...
Use the :not selector.
$(".thisclass:not(#thisid)").doAction();
If you have multiple ids or selectors just use the comma delimiter, in addition:
(".thisclass:not(#thisid,#thatid)").doAction();
...
For each row return the column name of the largest value
...what department they are in most often. It is trivial to tabulate employee ID against department name, but it is trickier to return the department name, rather than the number of roster counts, from the frequency table. A simple example below (column names = departments, row names = employee ids).
...
How to use GROUP_CONCAT in a CONCAT in MySQL
...
select id, group_concat(`Name` separator ',') as `ColumnName`
from
(
select
id,
concat(`Name`, ':', group_concat(`Value` separator ',')) as `Name`
from mytbl
group by
id,
`Name`
) tbl
group by id;
You can...
How to select unique records by SQL
...umns (at least on a DB2), which still will return duplicate values in individual columns.
– Konstantin
Jan 4 '18 at 10:46
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How to create and handle composite primary key in JPA
...contains your two keys, and then have a reference to that class as EmbeddedId in your Entity.
You would need the @EmbeddedId and @Embeddable annotations.
@Entity
public class YourEntity {
@EmbeddedId
private MyKey myKey;
@Column(name = "ColumnA")
private String columnA;
/** Y...
PostgreSQL delete with inner join
...
DELETE
FROM m_productprice B
USING m_product C
WHERE B.m_product_id = C.m_product_id AND
C.upc = '7094' AND
B.m_pricelist_version_id='1000020';
or
DELETE
FROM m_productprice
WHERE m_pricelist_version_id='1000020' AND
m_product_id IN (SELECT m_product...
In which case do you use the JPA @JoinTable annotation?
...le named Task and add a foreign key column to the task table named project_id:
Project Task
------- ----
id id
name name
project_id
This way, it will be possible to determine the project for each row in the task table. If you use this approach, in your en...
Get ID of last inserted document in a mongoDB w/ Java driver
Is there an easy way to get the ID (ObjectID) of the last inserted document of a mongoDB instance using the Java driver?
8 ...
How to change the foreign key referential action? (behavior)
...ess:
Suppose, a table1 has a foreign key with column name fk_table2_id, with constraint name fk_name and table2 is referred table with key t2 (something like below in my diagram).
table1 [ fk_table2_id ] --> table2 [t2]
First step, DROP old CONSTRAINT: (reference)
ALTER TABLE `t...