大约有 47,000 项符合查询结果（耗时：0.0626秒） [XML]
Run a PostgreSQL .sql file using command line arguments
I have some .sql files with thousands of INSERT statements in them and need to run these inserts on my PostgreSQL database in order to add them to a table. The files are that large that it is impossible to open them and copy the INSERT statements into an editor window and run them there. I found on ...
SQL WHERE ID IN (id1, id2, …, idn)
...
Option 3 is simply horrible performance-wise. It sends a query every loop and hammers the database with small queries. It also prevents it from using any optimizations for "value is one of those in a given list"
share
...
Should I commit or rollback a read transaction?
...tion, you should close it. Committing releases any locks you may have had, and is equally sensible with ReadUncommitted or Serializable isolation levels. Relying on implicit rollback - while perhaps technically equivalent - is just poor form.
If that hasn't convinced you, just imagine the next guy ...
How to get cumulative sum
... Col1,
SUM(Col1) OVER(ORDER BY RowId ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS Col2
FROM tablehh
ORDER BY RowId
or
SELECT
GroupID,
RowID,
Col1,
SUM(Col1) OVER(PARTITION BY GroupID ORDER BY RowId ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS Col2
FROM tabl...
How to debug PDO database queries?
...could just echo the final SQL query string, try it myself on the database, and tweak it until I fixed the error, then put that back into the code.
...
AngularJS - Any way for $http.post to send request parameters instead of JSON?
...ld code that is making an AJAX POST request through jQuery's post method and looks something like this:
13 Answers
...
How do I disable the “Press ENTER or type command to continue” prompt in Vim?
Is there any way to disable the "Press ENTER or type command to continue" prompt that appears after executing an external command?
...
Get model's fields in Django
... in front of meta indicate that the _meta attribute is a private attribute and shouldn't be accessed directly? ... Because, for example, the layout of _meta could change in the future and not be a stable API?
...
What does the property “Nonatomic” mean?
...
Take a look at the Apple Docs.
Basically, if you say nonatomic, and you generate the accessors using @synthesize, then if multiple threads try to change/read the property at once, badness can happen. You can get partially-written values or over-released/retained objects, which can easily ...
Convert javascript array to string
I'm trying to iterate over a "value" list and convert it into a string. Here is the code:
14 Answers
...