大约有 19,000 项符合查询结果（耗时：0.0240秒） [XML]
How to delete from select in MySQL?
...ner subquery result (looks rather hacky, though):
DELETE FROM posts WHERE id IN (
SELECT * FROM (
SELECT id FROM posts GROUP BY id HAVING ( COUNT(id) > 1 )
) AS p
)
Or use joins as suggested by Mchl.
sh...
How do I perform the SQL Join equivalent in MongoDB?
... The new $lookup operator added to the aggregation pipeline is essentially identical to a left outer join:
https://docs.mongodb.org/master/reference/operator/aggregation/lookup/#pipe._S_lookup
From the docs:
{
$lookup:
{
from: <collection to join>,
localField: <fiel...
How to annotate MYSQL autoincrement field with JPA annotations
...
To use a MySQL AUTO_INCREMENT column, you are supposed to use an IDENTITY strategy:
@Id @GeneratedValue(strategy=GenerationType.IDENTITY)
private Long id;
Which is what you'd get when using AUTO with MySQL:
@Id @GeneratedValue(strategy=GenerationType.AUTO)
private Long id;
Which is a...
How to get multiple counts with one SQL query?
...ally the same thing as a PIVOT function in some RDBMS:
SELECT distributor_id,
count(*) AS total,
sum(case when level = 'exec' then 1 else 0 end) AS ExecCount,
sum(case when level = 'personal' then 1 else 0 end) AS PersonalCount
FROM yourtable
GROUP BY distributor_id
...
Explicitly set Id with Doctrine when using “AUTO” strategy
My entity uses this annotation for it's ID:
7 Answers
7
...
Smooth scroll to div id jQuery
I've been trying to get a scroll to div id jquery code to work correctly. Based on another stack overflow question i tried the following
...
Optimal way to concatenate/aggregate strings
...ich should work fine in Azure.
;WITH Partitioned AS
(
SELECT
ID,
Name,
ROW_NUMBER() OVER (PARTITION BY ID ORDER BY Name) AS NameNumber,
COUNT(*) OVER (PARTITION BY ID) AS NameCount
FROM dbo.SourceTable
),
Concatenated AS
(
SELECT
ID,
CA...
Hibernate, @SequenceGenerator and allocationSize
...y 50 (default allocationSize value) - and then uses this value as entity ID.
6 Answers
...
Rails :include vs. :joins
...ails. Here is an explaination of what I understood (with examples :))
Consider this scenario:
A User has_many comments and a comment belongs_to a User.
The User model has the following attributes: Name(string), Age(integer). The Comment model has the following attributes:Content, user_id. For a ...
Oracle SQL: Update a table with data from another table
...c
FROM table2 t2
WHERE t1.id = t2.id)
WHERE EXISTS (
SELECT 1
FROM table2 t2
WHERE t1.id = t2.id )
Assuming the join results in a key-preserved view, you could also
UPDATE (SELECT t1.id,
t1.name name1,
...