大约有 37,000 项符合查询结果（耗时：0.0233秒） [XML]
How does MySQL process ORDER BY and LIMIT in a query?
...row.
select t.article
from
(select article, publish_date
from table1
order by publish_date desc limit 10) t
order by t.publish_date asc;
If you need all columns, it is done this way:
select t.*
from
(select *
from table1
order by publish_date desc limit 10) ...
SQLite - increase value by a certain number
is it possible to increase a certain value in a table by a certain number without reading last value and afterwards updating it?
...
Stored procedure slow when called from web, fast from Management Studio
... change:
ALTER PROCEDURE [dbo].[sproc]
@param1 int,
AS
SELECT * FROM Table WHERE ID = @param1
to:
ALTER PROCEDURE [dbo].[sproc]
@param1 int,
AS
DECLARE @param1a int
SET @param1a = @param1
SELECT * FROM Table WHERE ID = @param1a
Seems strange, but it fixed my problem.
...
Rails where condition using NOT NIL
...udes(:bar).where.not(bars: { id: nil })
When working with scopes between tables, I prefer to leverage merge so that I can use existing scopes more easily.
Foo.includes(:bar).merge(Bar.where.not(id: nil))
Also, since includes does not always choose a join strategy, you should use references here...
Why would you use Expression rather than Func?
...
@bertl Delegate is what CPU sees (executable code of one architecture), Expression is what compiler sees (merely another format of source code, but still source code).
– codewarrior
May 5 '17 at 9:22
...
Center a DIV horizontally and vertically [duplicate]
...
Nice to have a version without table-cell, thanks.
– devlord
Dec 20 '13 at 19:01
...
@UniqueConstraint and @Column(unique = true) in hibernate annotation
...hould have unique values. The same aplies for group.
On the other hand,
@Table(
name = "product_serial_group_mask",
uniqueConstraints = {@UniqueConstraint(columnNames = {"mask", "group"})}
)
Implies that the values of mask + group combined should be unique. That means you can have, for ex...
How do I set the time zone of MySQL?
...ed timezones like 'Europe/Helsinki' means that you have to have a timezone table properly populated.)
Keep in mind that +02:00 is an offset. Europe/Berlin is a timezone (that has two offsets) and CEST is a clock time that corresponds to a specific offset.
@@session.time_zone variable
SELECT @@ses...
Is it possible to use the SELECT INTO clause with UNION [ALL]?
In SQL Server this inserts 100 records, from the Customers table into tmpFerdeen :-
8 Answers
...
How do I spool to a CSV formatted file using SQLPLUS?
...t for numbers (avoid scientific notation on IDs)
spool myfile.csv
select table_name, tablespace_name
from all_tables
where owner = 'SYS'
and tablespace_name is not null;
Output will be like:
TABLE_PRIVILEGE_MAP ,SYSTEM
SYSTEM_PRIVILEGE_MAP ...