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How do you count the number of occurrences of a certain substring in a SQL varchar?
...mparing the lengths
Declare @string varchar(1000)
Set @string = 'a,b,c,d'
select len(@string) - len(replace(@string, ',', ''))
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Difference between SelectedItem, SelectedValue and SelectedValuePath
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Their names can be a bit confusing :). Here's a summary:
The SelectedItem property returns the entire object that your list is bound to. So say you've bound a list to a collection of Category objects (with each Category object having Name and ID properties). eg. ObservableCollection&l...
how can I Update top 100 records in sql server
...derived table to define the desired sort order as below.
;WITH CTE AS
(
SELECT TOP 100 *
FROM T1
ORDER BY F2
)
UPDATE CTE SET F1='foo'
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Recommended SQL database design for tags or tagging [closed]
...ries which you will do: Output all Tags for one Item, draw a Tag-Cloud and select all items for one Tag Title.
All Tags for one Item:
3-Table:
SELECT Tag.Title
FROM Tag
JOIN ItemTag ON Tag.TagID = ItemTag.TagID
WHERE ItemTag.ItemID = :id
2-Table:
SELECT Tag.Title
FROM Tag
WHERE Tag.Item...
What columns generally make good indexes?
...earching the results speedily from tables. So it is most important step to select which columns to be indexed. There are two major places where we can consider indexing: columns referenced in the WHERE clause and columns used in JOIN clauses. In short, such columns should be indexed against which yo...
Oracle query to fetch column names
...r case, I'd imagine the query would look something like:
String sqlStr= "
SELECT column_name
FROM all_tab_cols
WHERE table_name = 'USERS'
AND owner = '" +_db+ "'
AND column_name NOT IN ( 'PASSWORD', 'VERSION', 'ID' )"
Note that with this approach, you risk SQL injection.
EDIT: Uppercase...
Is it possible to insert multiple rows at a time in an SQLite database?
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This can be recast into SQLite as:
INSERT INTO 'tablename'
SELECT 'data1' AS 'column1', 'data2' AS 'column2'
UNION ALL SELECT 'data1', 'data2'
UNION ALL SELECT 'data1', 'data2'
UNION ALL SELECT 'data1', 'data2'
a note on performance
I originally used this technique to efficiently lo...
How to open a specific port such as 9090 in Google Compute Engine
...hoose "Firewalls rules"
Choose "Create Firewall Rule"
To apply the rule to select VM instances, select Targets > "Specified target tags", and enter into "Target tags" the name of the tag. This tag will be used to apply the new firewall rule onto whichever instance you'd like. Then, make sure the ...
Dialog to pick image from gallery or from camera
...hoto and for picking a photo. Just show a dialog with two options and upon selection, use the appropriate code.
To take picture from camera:
Intent takePicture = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(takePicture, 0);//zero can be replaced with any action code (called ...
postgresql - replace all instances of a string within text field
...g regex replacment. Let's see how easy it is to replace a cat with a dog.
SELECT regexp_replace('Cat bobcat cat cats catfish', 'cat', 'dog');
--> Cat bobdog cat cats catfish
SELECT regexp_replace('Cat bobcat cat cats catfish', 'cat', 'dog', 'i');
--> dog...