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How do you find the disk size of a Postgres / PostgreSQL table and its indexes
...
Try the Database Object Size Functions. An example:
SELECT pg_size_pretty(pg_total_relation_size('"<schema>"."<table>"'));
For all tables, something along the lines of:
SELECT
table_schema || '.' || table_name AS table_full_name,
pg_size_pretty(pg_total_...
How do I put an 'if clause' in an SQL string?
... WHERE purchaseOrder_ID = '@purchaseOrder_ID' and
not exists (SELECT *
FROM itemsOrdered WHERE purchaseOrder_ID = '@purchaseOrdered_ID' AND status = 'PENDING'
)
However, I might guess that you are looping at a higher level. To set all such v...
Ruby: Can I write multi-line string with no concatenation?
... HEREDOC syntax (via this link):
p <<END_SQL.gsub(/\s+/, " ").strip
SELECT * FROM users
ORDER BY users.id DESC
END_SQL
# >> "SELECT * FROM users ORDER BY users.id DESC"
The latter would mostly be for situations that required more flexibility in the processing. I personall...
Good Hash Function for Strings
...ng it might be a good idea to sum up the unicode values for the first five characters in the string (assuming it has five, otherwise stop where it ends). Would that be a good idea, or is it a bad one?
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PowerShell equivalent to grep -f
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The -Pattern parameter in Select-String supports an array of patterns. So the one you're looking for is:
Get-Content .\doc.txt | Select-String -Pattern (Get-Content .\regex.txt)
This searches through the textfile doc.txt by using every regex(one pe...
Get table column names in MySQL?
...DESCRIBE my_table;
Or in newer versions you can use INFORMATION_SCHEMA:
SELECT COLUMN_NAME
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_SCHEMA = 'my_database' AND TABLE_NAME = 'my_table';
Or you can use SHOW COLUMNS:
SHOW COLUMNS FROM my_table;
...
Reliable method to get machine's MAC address in C#
...aces()
where nic.OperationalStatus == OperationalStatus.Up
select nic.GetPhysicalAddress().ToString()
).FirstOrDefault();
Or:
String firstMacAddress = NetworkInterface
.GetAllNetworkInterfaces()
.Where( nic => nic.OperationalStatus == OperationalStatus.Up &&...
Change default text in input type=“file”?
...e of label for input.
<div>
<label for="files" class="btn">Select Image</label>
<input id="files" style="visibility:hidden;" type="file">
</div>
Below is the code to fetch name of the uploaded file
$("#files").change(function() {
filename = this.files[...
LINQ's Distinct() on a particular property
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(this IEnumerable<TSource> source, Func<TSource, TKey> keySelector)
{
HashSet<TKey> seenKeys = new HashSet<TKey>();
foreach (TSource element in source)
{
if (seenKeys.Add(keySelector(element)))
{
yield return element;
}
...
Why do we always prefer using parameters in SQL statements?
I am very new to working with databases. Now I can write SELECT , UPDATE , DELETE , and INSERT commands. But I have seen many forums where we prefer to write:
...