大约有 5,887 项符合查询结果（耗时：0.0238秒） [XML]
MySQL show current connection info
...7 min 16 sec
Threads: 1 Questions: 21 Slow queries: 0 Opens: 33 Flush tables: 1 Open tables: 26 Queries per second avg: 0.48
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github markdown colspan
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You can use HTML tables on GitHub (but not on StackOverflow)
<table>
<tr>
<td>One</td>
<td>Two</td>
</tr>
<tr>
<td colspan="2">Three</td>
</tr>
</table&...
How to change height of grouped UITableView header?
I know how to change the height of the section headers in the table view. But I am unable to find any solution to change the default spacing before the first section.
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Create the perfect JPA entity [closed]
...to create entities I find myself struggling with issues as AccessType, immutable properties, equals/hashCode, ... .
So I decided to try and find out the general best practice for each issue and write this down for personal use.
I would not mind however for anyone to comment on it or to tell me w...
How do I bind Twitter Bootstrap tooltips to dynamically created elements?
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great! for use inside a table add container: 'body' to avoid extra width.
– shock_gone_wild
Jan 19 '16 at 16:31
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Why is a “GRANT USAGE” created the first time I grant a user privileges?
...e MySQL server, hence USAGE. It corresponds to a row in the `mysql`.`user` table with no privileges set.
The IDENTIFIED BY clause indicates that a password is set for that user. How do we know a user is who they say they are? They identify themselves by sending the correct password for their accoun...
Where does PostgreSQL store the database?
...ory;
To see all the run-time parameters, use
show all;
You can create tablespaces to store database objects in other parts of the filesystem. To see tablespaces, which might not be in that data directory, use this query.
SELECT * FROM pg_tablespace;
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T-SQL get SELECTed value of stored procedure
...set
ALSO, watch out if you use the pattern: SELECT @Variable=column FROM table ...
if there are multiple rows returned from the query, your @Variable will only contain the value from the last row returned by the query.
RETURN VALUE
since your query returns an int field, at least based on how you...
How to get the top 10 values in postgresql?
... *,
rank() over (order by some_value_column desc) as my_rank
from mytable) subquery
where my_rank <= 10
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How to prevent ifelse() from turning Date objects into numeric objects
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You may use data.table::fifelse (data.table >= 1.12.3) or dplyr::if_else.
data.table::fifelse
Unlike ifelse, fifelse preserves the type and class of the inputs.
library(data.table)
dates <- fifelse(dates == '2011-01-01', dates - 1, d...