大约有 47,000 项符合查询结果（耗时：0.0496秒） [XML]
NULL values inside NOT IN clause
...
Query A is the same as:
select 'true' where 3 = 1 or 3 = 2 or 3 = 3 or 3 = null
Since 3 = 3 is true, you get a result.
Query B is the same as:
select 'true' where 3 <> 1 and 3 <> 2 and 3 <> null
When ansi_nulls is on, 3 <&...
SQL Inner-join with 3 tables?
...
You can do the following (I guessed on table fields,etc)
SELECT s.studentname
, s.studentid
, s.studentdesc
, h.hallname
FROM students s
INNER JOIN hallprefs hp
on s.studentid = hp.studentid
INNER JOIN halls h
on hp.hallid = h.hallid
Based on your request for ...
How do I see all foreign keys to a table or column?
...
For a Table:
SELECT
TABLE_NAME,COLUMN_NAME,CONSTRAINT_NAME, REFERENCED_TABLE_NAME,REFERENCED_COLUMN_NAME
FROM
INFORMATION_SCHEMA.KEY_COLUMN_USAGE
WHERE
REFERENCED_TABLE_SCHEMA = '<database>' AND
REFERENCED_TABLE_NAME = '<...
Mac SQLite editor [closed]
... info.plist and setting it to YES
Running the app on a device
Open iTunes
Select the device
Select the "Apps" tab
Scroll down to the "File Sharing" section and select the app
The .sqlite file should appear in the right hand pane - select it and "Save to..."
Once it's saved open it up in your favour...
Xcode 6 Storyboard the wrong size?
...way at some point."
You probably haven't added the layout constraints.
Select your label, tap the layout constraints button on the bottom:
On that menu add width and height (it should NOT be the same as mine) by checking their checkbox and click add constraints. Then Control-drag your label t...
Best way to work with dates in Android SQLite [closed]
...ing (that is newest date goes first):
public static final String QUERY = "SELECT table._id, table.dateCol FROM table ORDER BY table.dateCol DESC";
//...
Cursor cursor = rawQuery(QUERY, null);
cursor.moveToFirst();
while (!cursor.isAfterLast()) {
// Process results
}
Al...
How to test an SQL Update statement before running it?
...yway) you can also do a sanity check which rows are affected by running a select using the same WHERE clause as the UPDATE.
So if you UPDATE is
UPDATE foo
SET bar = 42
WHERE col1 = 1
AND col2 = 'foobar';
The following will show you which rows will be updated:
SELECT *
FROM foo
WHERE col1 ...
Restful way for deleting a bunch of items
...away with the javascript confirm on the same page, and instead, create the selection and redirect to it, showing a confirm message on that page. In other words:
From:
http://example.com/resources/
do a
POST with a selection of the ID's to:
http://example.com/resources/selections
which, if succes...
Couldn't connect to server 127.0.0.1:27017
...mongodb is terminating because there is an old lock file.
If you are not and were not running with journaling, remove the lock file, run repair, and start mongodb again.
If you are or were running with journaling turned on, see the relevant Mongo DB docs. Note that they say "If you are running wi...
How can I get column names from a table in SQL Server?
... much more by querying the Information Schema views.
This sample query:
SELECT *
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_NAME = N'Customers'
Can be made over all these DB objects:
CHECK_CONSTRAINTS
COLUMN_DOMAIN_USAGE
COLUMN_PRIVILEGES
COLUMNS
CONSTRAINT_COLUMN_USAGE
CONSTRAINT_...