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Random record from MongoDB
...llection.
db.mycoll.aggregate([{ $sample: { size: 1 } }])
If you want to select the random document(s) from a filtered subset of the collection, prepend a $match stage to the pipeline:
// Get one random document matching {a: 10} from the mycoll collection.
db.mycoll.aggregate([
{ $match: { a:...
Can Android Studio be used to run standard Java projects?
...id Studio. If you do not have one, create one.
Click File > New Module. Select Java Library and click Next.
Fill in the package name, etc and click Finish. You should now see a Java module inside your Android project.
Add your code to the Java module you've just created.
Click on the drop down to...
Set database from SINGLE USER mode to MULTI USER
...onnected to it” might be SQL Server Management Studio window itself. Try selecting the master database and running the ALTER query again.
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How can I use swift in Terminal?
...
sudo xcode-select -switch /Applications/Xcode.app/Contents/Developer
then you can do one of these:
xcrun swift
lldb --repl
As of Xcode 6.1 - typing swift in the terminal launches the REPL as well.
...
TFS: Updating branch with changes from main
...
From Visual Studio, open Source Control Explorer:
View | Team Explorer
Select your Team Project from Team Explorer, expand it, and double click Source Control
In the left-hand pane of Source Control Explorer, select your Team Project.
In the right-hand pane, find your mainline branch, right-clic...
Postgres: SQL to list table foreign keys
...
You can do this via the information_schema tables. For example:
SELECT
tc.table_schema,
tc.constraint_name,
tc.table_name,
kcu.column_name,
ccu.table_schema AS foreign_table_schema,
ccu.table_name AS foreign_table_name,
ccu.column_name AS foreign_column_nam...
Unicode, UTF, ASCII, ANSI format differences
...ny other places, it means UTF-8. Properly, Unicode refers to the abstract character set itself, not to any particular encoding.
UTF-16: 2 bytes per "code unit". This is the native format of strings in .NET, and generally in Windows and Java. Values outside the Basic Multilingual Plane (BMP) are enc...
How do I rename a column in a SQLite database table?
...lite.org/images/syntax/alter-table-stmt.gif
Example:
CREATE TABLE tab AS SELECT 1 AS c;
SELECT * FROM tab;
ALTER TABLE tab RENAME COLUMN c to c_new;
SELECT * FROM tab;
db-fiddle.com demo
Android Support
As of writing, Android's API 27 is using SQLite package version 3.19.
Based on the cu...
Count work days between two dates
...
For workdays, Monday to Friday, you can do it with a single SELECT, like this:
DECLARE @StartDate DATETIME
DECLARE @EndDate DATETIME
SET @StartDate = '2008/10/01'
SET @EndDate = '2008/10/31'
SELECT
(DATEDIFF(dd, @StartDate, @EndDate) + 1)
-(DATEDIFF(wk, @StartDate, @EndDate) *...
proper hibernate annotation for byte[]
...dar, java.sql.Date,
java.sql.Time, java.sql.Timestamp,
byte[], Byte[], char[], Character[], enums, and any other
type that implements Serializable.
As described in Section 2.8, the use
of the Basic annotation is optional
for persistent fields and properties
of these types. If the Basic...