大约有 41,000 项符合查询结果（耗时：0.0535秒） [XML]
Is there a way to access the “previous row” value in a SELECT statement?
...d to order by some column for this to be meaningful. Something like this:
select t1.value - t2.value from table t1, table t2
where t1.primaryKey = t2.primaryKey - 1
If you know how to order things but not how to get the previous value given the current one (EG, you want to order alphabetically) ...
How do you read a file into a list in Python? [duplicate]
...so, watch your backslashes in windows path names, as those are also escape chars in strings. You can use forward slashes or double backslashes instead.
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SQLite - UPSERT *not* INSERT or REPLACE
... (id, role, name)
VALUES ( 1,
'code monkey',
(SELECT name FROM Employee WHERE id = 1)
);
This will update 2 of the columns.
When ID=1 exists, the ROLE will be unaffected.
When ID=1 does not exist, the role will be set to 'Benchwarmer' instead of the default v...
Android ViewPager with bottom dots
...droid:layout_height="wrap_content"
app:tabBackground="@drawable/tab_selector"
app:tabGravity="center"
app:tabIndicatorHeight="0dp"/>
</RelativeLayout>
Hook up your UI elements inactivity or fragment as follows:
Java Code:
mImageViewPager = (ViewPager) findViewById(R.id...
What is the best way to conditionally apply a class?
...ul with an li for each element and a property on the controller called selectedIndex . What would be the best way to add a class to the li with the index selectedIndex in AngularJS?
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How to get value of selected radio button?
I want to get the selected value from a group of radio buttons.
28 Answers
28
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Change limit for “Mysql Row size too large”
...rows of your
tables plus the length of other variable length fields (VARCHAR, VARBINARY, and TEXT type fields).
In my situation the offending blob table was around 16MB. Thus, the way I solved it was by adding a line to my.cnf that ensured I had at least 10x that amount and then some:
innodb_l...
What is this operator in MySQL?
...d <> both give UNKNOWN with NULL on either side of the expression.)
SELECT *
FROM table
WHERE YourColumn IS NOT NULL;
can also negate the null safe equality operator but this is not standard SQL.
SELECT *
FROM table
WHERE NOT (YourColumn <=> NULL);
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how to emulate “insert ignore” and “on duplicate key update” (sql merge) with postgresql?
... two queries, one for INSERT and one for UPDATE (as an appropriate join/subselect of course - no need to write your main filter twice)
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LINQ Using Max() to select a single row
I'm using LINQ on an IQueryable returned from NHibernate and I need to select the row with the maximum value(s) in a couple of fields.
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