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How can one see the structure of a table in SQLite? [duplicate]
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You can query sqlite_master
SELECT sql FROM sqlite_master WHERE name='foo';
which will return a create table SQL statement, for example:
$ sqlite3 mydb.sqlite
sqlite> create table foo (id int primary key, name varchar(10));
sqlite> select sql f...
Show an image preview before upload
... code snippet in the HTML example below filters out images from the user's selection and renders selected files into multiple thumbnail previews:
function handleFileSelect(evt) {
var files = evt.target.files;
// Loop through the FileList and render image files as thumbnails.
fo...
Where are my postgres *.conf files?
...alives_idle = 0 # TCP_KEEPIDLE, in seconds;
# 0 selects the system default
#tcp_keepalives_interval = 0 # TCP_KEEPINTVL, in seconds;
# 0 selects the system default
#tcp_keepalives_count = 0 # TCP_KEEPCNT;
# 0 selects the...
How do I select the “last child” with a specific class name in CSS? [duplicate]
How do I select the "last child" with the class name: list ?
6 Answers
6
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Proper way to renew distribution certificate for iOS
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Login to Member Center > Certificates, Identifiers & Profiles, select the expiring certificate. Take note of the expiry date of the certificate, and click the ‘Revoke’ button.
Step 2: (Optional) Remove the revoked certificate from your Keychain
Optionally, if you don't want to ha...
Ruby Arrays: select(), collect(), and map()
...re, to check the :qty key, you'd do something like the following:
details.select{ |item| item[:qty] != "" }
That will give you all items where the :qty key isn't an empty string.
official select documentation
share
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Wrong Manifest.mf in IntelliJ IDEA created .jar
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To fix:
File > Project Structure
Under Project Settings on the left, select "Artifacts"
Find the JAR definition In the middle pane and select it
In the left pane of the "Output Layout" tab find the jar file in the list and select it
At the bottom, click the "Use Existing Manifest" button and s...
What is Ad Hoc Query?
... SQL query you just loosely type out where you need it
var newSqlQuery = "SELECT * FROM table WHERE id = " + myId;
...which is an entirely different query each time that line of code is executed, depending on the value of myId. The opposite of an ad hoc query is a predefined query such as a Store...
The cast to value type 'Int32' failed because the materialized value is null
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where u.ID == userID
select (int?)ch.Amount).Sum() ?? 0;
This first casts to int? to tell the C# compiler that this expression can indeed return null, even though Sum() returns an int. Then we use the normal ?? operator to handle the null case....
CSS “and” and “or”
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&& works by stringing-together multiple selectors like-so:
<div class="class1 class2"></div>
div.class1.class2
{
/* foo */
}
Another example:
<input type="radio" class="class1" />
input[type="radio"].class1
{
/* foo */
}
|| works by se...