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Copy a table from one database to another in Postgres
... follow these steps:
In pgAdmin, right click the table you want to move, select "Backup"
Pick the directory for the output file and set Format to "plain"
Click the "Dump Options #1" tab, check "Only data" or "only Schema" (depending on what you are doing)
Under the Queries section, click "Use Colu...
How do MySQL indexes work?
...be faster to go through the pages one by one (in a database, this is "poor selectivity").
For a 10-page book, it makes no sense to make an index, as you may end up with a 10-page book prefixed by a 5-page index, which is just silly - just scan the 10 pages and be done with it.
The index also needs t...
The entity cannot be constructed in a LINQ to Entities query
... p in db.Products
where p.CategoryID == categoryID
select new ProductDTO { Name = p.Name }).ToList();
}
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SQLAlchemy: print the actual query
...s:
print(str(statement))
This applies both to an ORM Query as well as any select() or other statement.
Note: the following detailed answer is being maintained on the sqlalchemy documentation.
To get the statement as compiled to a specific dialect or engine, if the statement itself is not already bo...
Is there a CSS parent selector?
How do I select the <li> element that is a direct parent of the anchor element?
33 Answers
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Can PHP PDO Statements accept the table or column name as parameter?
... case 1:
$tbl = 'users';
break;
}
$sql = "SELECT * FROM $tbl";
}
By leaving no default case or using a default case that returns an error message you ensure that only values that you want used get used.
...
Comparing date ranges
... range_start, here's some simple SQL to retrieve all the matching rows:
SELECT *
FROM periods
WHERE NOT (range_start > @check_period_end
OR range_end < @check_period_start)
Note the NOT in there. Since the two simple rules finds all the non-matching rows, a simple NOT will reve...
Can I have multiple Xcode versions installed?
... explicitly specify it at install time. Also, you will generally want to unselect all features besides the xcode core tools, because the others don't let you change the install directory.
– Paul Du Bois
Jul 3 '11 at 3:30
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What is the way to quick-switch between tabs in Xcode 4
...
Shortcuts are:
CMD + SHIFT + } - Select Next tab
CMD + SHIFT + { - Select Previous tab
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OR is not supported with CASE Statement in SQL Server
...sions anywhere in the SQL queries. CASE expressions can be used within the SELECT statement, WHERE clauses, Order by clause, HAVING clauses, Insert, UPDATE and DELETE statements.
A CASE expression has the following two formats:
Simple CASE expression
CASE expression
WHEN expression1 THEN Result1...