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Is there a naming convention for MySQL?
...e your standard, then run with it.
To answer your question outright - no, MySQL doesn't have a preferred naming convention/standard, so rolling your own is fine (and yours seems logical).
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String concatenation does not work in SQLite
...
Try using || in place of +
select locationname || '<p>' from location;
From SQLite documentation:
The || operator is "concatenate" - it joins together the two strings of its operands.
...
How to convert an image to base64 encoding?
...
Here is the code for upload to encode and save it to the MySQL
if (!isset($_GET["getfile"])) {
if ($_FILES["file"]["error"] > 0) {
echo "Error: " . $_FILES["file"]["error"] . "<br>";
} else {
move_uploaded_file($_FILES["file"]["tmp_name"], $_FILES[...
Are there disadvantages to using a generic varchar(255) for all text-based fields?
...ould always store 255 characters.
But since you tagged this question with MySQL, I'll mention a MySQL-specific tip: as rows are copied from the storage engine layer to the SQL layer, VARCHAR fields are converted to CHAR to gain the advantage of working with fixed-width rows. So the strings in mem...
View contents of database file in Android Studio
...File Explorer (one of the tabs on the right), go to /data/data/databases
Select the database by just clicking on it.
Go to the top right corner of the Android Device Monitor window. Click on the 'pull a file from the device' button:
A window will open asking you where you want to save your data...
PostgreSQL: Modify OWNER on all tables simultaneously in PostgreSQL
...and sequences too. Here's what I did:
Tables:
for tbl in `psql -qAt -c "select tablename from pg_tables where schemaname = 'public';" YOUR_DB` ; do psql -c "alter table \"$tbl\" owner to NEW_OWNER" YOUR_DB ; done
Sequences:
for tbl in `psql -qAt -c "select sequence_name from information_schem...
Select rows which are not present in other table
...task, all of them standard SQL.
NOT EXISTS
Often fastest in Postgres.
SELECT ip
FROM login_log l
WHERE NOT EXISTS (
SELECT -- SELECT list mostly irrelevant; can just be empty in Postgres
FROM ip_location
WHERE ip = l.ip
);
Also consider:
What is easier to read in EXISTS...
Foreign key constraints: When to use ON UPDATE and ON DELETE
I'm designing my database schema using MySQL Workbench, which is pretty cool because you can do diagrams and it converts them :P
...
Data binding to SelectedItem in a WPF Treeview
How can I retrieve the item that is selected in a WPF-treeview? I want to do this in XAML, because I want to bind it.
20 An...
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