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What does SQL clause “GROUP BY 1” mean?
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SELECT account_id, open_emp_id
^^^^ ^^^^
1 2
FROM account
GROUP BY 1;
In above query GROUP BY 1 refers to the first column in select statement which is
account_id.
You also can speci...
How to check existence of user-define table type in SQL Server 2008?
...y. You can't use OBJECT_ID to search for a table type by name -- check out SELECT name FROM sys.objects WHERE type = 'TT'
– NReilingh
Nov 29 '15 at 9:17
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What can you use Python generator functions for?
...uld like to update Alexa rank for each domain.
First thing you need is to select your domain names from the database.
Let's say your table name is domains and column name is domain.
If you use SELECT domain FROM domains it's going to return 100 million rows which is going to consume lot of memory...
Solving “The ObjectContext instance has been disposed and can no longer be used for operations that
... to find out where the reference is or isn't set, right-click its name and select "Find All References". You can then place a breakpoint at every location that requests data, and run your program with the debugger attached. Every time the debugger breaks on such a breakpoint, you need to determine w...
How can I use swift in Terminal?
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sudo xcode-select -switch /Applications/Xcode.app/Contents/Developer
then you can do one of these:
xcrun swift
lldb --repl
As of Xcode 6.1 - typing swift in the terminal launches the REPL as well.
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COUNT DISTINCT with CONDITIONS
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You can try this:
select
count(distinct tag) as tag_count,
count(distinct (case when entryId > 0 then tag end)) as positive_tag_count
from
your_table_name;
The first count(distinct...) is easy.
The second one, looks somewhat complex...
How to take backup of a single table in a MySQL database?
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You can use easily to dump selected tables using MYSQLWorkbench tool ,individually or group of tables at one dump then import it as follow: also u can add host information if u are running it in your local by adding -h IP.ADDRESS.NUMBER after-u usernam...
T-SQL CASE Clause: How to specify WHEN NULL
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Given your query you can also do this:
SELECT first_name + ' ' + ISNULL(last_name, '') AS Name FROM dbo.person
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Difference between clustered and nonclustered index [duplicate]
...a completely different object within the table that contains the column(s) selected for indexing and a pointer back to the table’s rows containing the data. It is like an index in the last pages of a book, where keywords are sorted and contain the page number to the material of the book for faster...
How can I prevent SQL injection in PHP?
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Using PDO (for any supported database driver):
$stmt = $pdo->prepare('SELECT * FROM employees WHERE name = :name');
$stmt->execute([ 'name' => $name ]);
foreach ($stmt as $row) {
// Do something with $row
}
Using MySQLi (for MySQL):
$stmt = $dbConnection->prepare('SELECT * FROM...