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ALTER TABLE to add a composite primary key
...dexed from left to right.
For example, consider the following queries:
A) SELECT person, place, thing FROM provider WHERE person = 'foo' AND thing = 'bar';
B) SELECT person, place, thing FROM provider WHERE person = 'foo' AND place = 'baz';
C) SELECT person, place, thing FROM provider WHERE person ...
Cannot create or edit Android Virtual Devices (AVD) from Eclipse, ADT 22.6
...lone button worked and I was able to successfully edit the clone.
Steps:
Select a Device by Google
Click the "Clone..." button
A window will pop up, click "Clone device"
Select the newly cloned Device, it should say "... by User"
Click the "Edit" button on the side
There you have it...
Is there a MySQL option/feature to track history of changes to records?
...i AFTER INSERT ON MyDB.data FOR EACH ROW
INSERT INTO MyDB.data_history SELECT 'insert', NULL, NOW(), d.*
FROM MyDB.data AS d WHERE d.primary_key_column = NEW.primary_key_column;
CREATE TRIGGER MyDB.data__au AFTER UPDATE ON MyDB.data FOR EACH ROW
INSERT INTO MyDB.data_history SELECT 'up...
How to compare only date components from DateTime in EF?
...m having two date values, one already stored in the database and the other selected by the user using DatePicker. The use case is to search for a particular date from the database.
...
Should I use the datetime or timestamp data type in MySQL?
...o with the native format. You can do calculations within MySQL that way
("SELECT DATE_ADD(my_datetime, INTERVAL 1 DAY)") and it is simple to change the format of the value to a UNIX timestamp ("SELECT UNIX_TIMESTAMP(my_datetime)") when you query the record if you want to operate on it with PHP.
...
Move entire line up and down in Vim
...;A-down> but when I try those keys in vim in visual running in tmux the selection disappears and the cursor moves line up; without moving the selected lines.
– Konrad
Dec 27 '16 at 9:49
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Transaction isolation levels relation with locks on table
... writes data and commit/rollback (depending on results). B just executes a SELECT statement to read data. C reads and updates data. All these process work on the same table T.
READ UNCOMMITTED - no lock on the table. You can read data in the table while writing on it. This means A writes data (unc...
How to write a simple Html.DropDownListFor()?
...%= Html.DropDownListFor(n => n.MyColorId,
new SelectList(Colors, "ColorId", "Name")) %>
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What are “first class” objects?
...es.
In Java, for example, there are primitive types (int, bool, double, char) that aren't proper objects. That's why Java has to introduce Integer, Boolean, Double, and Character as first-class types. This can be hard to teach to beginners -- it isn't obvious why both a primitive type and a cla...
Entity Framework - Include Multiple Levels of Properties
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For EF 6
using System.Data.Entity;
query.Include(x => x.Collection.Select(y => y.Property))
Make sure to add using System.Data.Entity; to get the version of Include that takes in a lambda.
For EF Core
Use the new method ThenInclude
query.Include(x => x.Collection)
.ThenIncl...