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Does the join order matter in SQL?
... (commutativity and associativity) properties:
a LEFT JOIN b
ON b.ab_id = a.ab_id
LEFT JOIN c
ON c.ac_id = a.ac_id
is equivalent to:
a LEFT JOIN c
ON c.ac_id = a.ac_id
LEFT JOIN b
ON b.ab_id = a.ab_id
but:
a LEFT JOIN b
ON b.ab_id = a.ab_id
LEFT JOIN c
ON c....
How to properly create composite primary keys - MYSQL
...le_1 and table_2 both have auto-increment surrogate primary keys as the ID. info is a table that contains information about both table_1 and table_2 .
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Handling a Menu Item Click Event - Android
...icked, but I'm not sure how to do this. I've been reading through the android documentation, but my implementation isn't correct..and some guidance in the right direction would help. I've listed my code below and commented out my problem areas, I think I'm invoking the wrong method.
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How do you list the primary key of a SQL Server table?
...E_SCHEMA = '<your schema name>'" as well.
– DavidStein
May 17 '13 at 15:56
If the above query returns 3 rows, a,...
Getting the ID of the element that fired an event
Is there any way to get the ID of the element that fires an event?
22 Answers
22
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How to access the GET parameters after “?” in Express?
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Could you please tell me how to validate "id" ?
– Anand Raj
Feb 9 '17 at 8:47
1
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Delete all Duplicate Rows except for One in MySQL? [duplicate]
...e.
NB - You need to do this first on a test copy of your table!
When I did it, I found that unless I also included AND n1.id <> n2.id, it deleted every row in the table.
If you want to keep the row with the lowest id value:
DELETE n1 FROM names n1, names n2 WHERE n1.id > n2.id AND n...
How to set radio button checked as default in radiogroup?
...hould check the radiobutton in the radiogroup like this:
radiogroup.check(IdOfYourButton)
Of course you first have to set an Id to your radiobuttons
EDIT: i forgot, radioButton.getId() works as well, thx Ramesh
EDIT2:
android:checkedButton="@+id/my_radiobtn"
works in radiogroup xml
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Duplicate ID, tag null, or parent id with another fragment for com.google.android.gms.maps.MapFragme
...r, I found a solution that works for me:
private static View view;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
if (view != null) {
ViewGroup parent = (ViewGroup) view.getParent();
if (parent != null)
...
MySQL select one column DISTINCT, with corresponding other columns
...STINCT results from the FirstName column, but I need the corresponding ID and LastName .
12 Answers
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