大约有 9,000 项符合查询结果（耗时：0.0277秒） [XML]
Exit single-user mode
...the processes that have been currently running.
Then, run the following T-SQL to set the database in MULTI_USER mode.
USE master
GO
DECLARE @kill varchar(max) = '';
SELECT @kill = @kill + 'KILL ' + CONVERT(varchar(10), spid) + '; '
FROM master..sysprocesses
WHERE spid > 50 AND dbid = DB_ID('&l...
Store pictures as files or in the database for a web app?
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Also, in SQL Server when you store the image as an "Image" field, this is effectively what SQL is doing - storing a pointer to the file on disk somewhere. This is how it gets around the 8KB page limit.
– Zhaph - ...
Store query result in a variable using in PL/pgSQL
How to assign the result of a query to a variable in PL/pgSQL, the procedural language of PostgreSQL?
5 Answers
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Are there any disadvantages to always using nvarchar(MAX)?
In SQL Server 2005, are there any disadvantages to making all character fields nvarchar(MAX) rather than specifying a length explicitly, e.g. nvarchar(255)? (Apart from the obvious one that you aren't able to limit the field length at the database level)
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IN clause and placeholders
I'm attempting to do the following SQL query within Android:
9 Answers
9
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Max return value if empty query
...on the result. I also think (I haven't tested this yet) that the generated SQL would use an extra subselect query by doing that, while mine would just deal with an empty set by returning null. Thanks for the upvote and feedback! ;)
– CptRobby
Nov 22 '16 at 14:3...
How do I check if an index exists on a table field in MySQL?
...Use SHOW INDEX like so:
SHOW INDEX FROM [tablename]
Docs: https://dev.mysql.com/doc/refman/5.0/en/show-index.html
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IEnumerable vs List - What to Use? How do they work?
... and possibly optimize the program. Remember how LINQ doesn't generate the SQL to query the database until you enumerate it? Consider this:
public IEnumerable<Animals> AllSpotted()
{
return from a in Zoo.Animals
where a.coat.HasSpots == true
select a;
}
public IEnum...
How do I select an entire row which has the largest ID in the table?
...ow profiles and it appears our solutions have the same performance using MySQL. For my own knowledge, do you know what DBMS has poorer performance for subselects?
– unutbu
Feb 7 '14 at 20:08
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Why shouldn't I use mysql_* functions in PHP?
What are the technical reasons for why one shouldn't use mysql_* functions? (e.g. mysql_query() , mysql_connect() or mysql_real_escape_string() )?
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