大约有 48,000 项符合查询结果（耗时：0.0352秒） [XML]
String.Join method that ignores empty strings?
... simpler, since you can do it in SQL directly:
PostgreSQL & MySQL:
SELECT
concat_ws(' / '
, NULLIF(searchTerm1, '')
, NULLIF(searchTerm2, '')
, NULLIF(searchTerm3, '')
, NULLIF(searchTerm4, '')
) AS RPT_SearchTerms;
And even with the glorious MS-SQ...
select and update database record with a single queryset
How do I run an update and select statements on the same queryset rather than having to do two queries:
- one to select the object
- and one to update the object
...
SQL Server - Return value after INSERT
...
No need for a separate SELECT...
INSERT INTO table (name)
OUTPUT Inserted.ID
VALUES('bob');
This works for non-IDENTITY columns (such as GUIDs) too
share
|
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MySQL - force not to use cache for testing speed of query
...ACHE (MySQL 5.7) option in your query.
(MySQL 5.6 users click HERE )
eg.
SELECT SQL_NO_CACHE * FROM TABLE
This will stop MySQL caching the results, however be aware that other OS and disk caches may also impact performance. These are harder to get around.
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How to select an element inside “this” in jQuery?
I know can I select an element this way:
2 Answers
2
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What GRANT USAGE ON SCHEMA exactly do?
...a schema doesn't grant rights on the tables within.
If you have rights to SELECT from a table, but not the right to see it in the schema that contains it then you can't access the table.
The rights tests are done in order:
Do you have `USAGE` on the schema?
No: Reject access.
Yes: Do...
EOL conversion in notepad ++
...That functionality is already built into Notepad++. From the "Edit" menu, select "EOL Conversion" -> "UNIX/OSX Format".
screenshot of the option for even quicker finding (or different language versions)
You can also set the default EOL in notepad++ via "Settings" -> "Preferences" -> "New...
MySQL and GROUP_CONCAT() maximum length
...You should use it like this.
SET SESSION group_concat_max_len = 1000000;
select group_concat(column) from table group by column
You can do this even in sharing hosting, but when you use an other session, you need to repeat the SET SESSION command.
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Ordering by the order of values in a SQL IN() clause
...
Use MySQL's FIELD() function:
SELECT name, description, ...
FROM ...
WHERE id IN([ids, any order])
ORDER BY FIELD(id, [ids in order])
FIELD() will return the index of the first parameter that is equal to the first parameter (other than the first paramet...
How do I query for all dates greater than a certain date in SQL Server?
...
select *
from dbo.March2010 A
where A.Date >= Convert(datetime, '2010-04-01' )
In your query, 2010-4-01 is treated as a mathematical expression, so in essence it read
select *
from dbo.March2010 A
where A.Date &g...