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MySQL pagination without double-querying?
... this tickles that affects ORDER BY queries making it much slower on large tables than the naive approach of two queries.
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PostgreSQL: How to make “case-insensitive” query
...indexes to no longer be seekable. If this is a large or frequently queried table, that could cause trouble. Case-insensitive collation, citext, or a function-based index will improve performance.
– Jordan
Aug 10 '11 at 4:23
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What is the difference between ExecuteScalar, ExecuteReader and ExecuteNonQuery?
...ny result set with multiple rows/columns (e.g., SELECT col1, col2 from sometable).
ExecuteNonQuery is typically used for SQL statements without results (e.g., UPDATE, INSERT, etc.).
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SQL multiple column ordering
... @NickBenes ...or you could say: it sorts by column2 and then performs STABLE sorting by column1. This is more clear for people that knows what stable sorting is.
– Atom
Oct 3 '16 at 13:49
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Only one expression can be specified in the select list when the subquery is not introduced with EXI
...r side of the IN. So the query needs to be of the form:
SELECT * From ThisTable WHERE ThisColumn IN (SELECT ThatColumn FROM ThatTable)
You also want to add sorting so you can select just from the top rows, but you don't need to return the COUNT as a column in order to do your sort; sorting in the...
ng-repeat finish event
I want to call some jQuery function targeting div with table. That table is populated with ng-repeat .
15 Answers
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LINQ Join with Multiple Conditions in On Clause
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This works fine for 2 tables. I have 3 tables and on clause has to link 2 conditions from 3 tables.
My code:
from p in _dbContext.Products
join pv in _dbContext.ProductVariants on p.ProduktId equals pv.ProduktId
join jpr in leftJoinQuery
on new {...
convert_tz returns null
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This will happen if you haven't loaded the time zone table into mysql.
mysql_tzinfo_to_sql /usr/share/zoneinfo | mysql -u root -p mysql
mysql is the name of the built-in database that holds MySQL-specific configuration data.
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Why are ToLookup and GroupBy different?
...happens when you call ToLookup on an object representing a remote database table with a billion rows in it?
The billion rows are sent over the wire, and you build the lookup table locally.
What happens when you call GroupBy on such an object?
A query object is built; end of story.
When that quer...
Still Reachable Leak detected by Valgrind
... reachable" memory can be considered a memory leak: assume you have a hash table where you add pointers to heap allocated memory as value. If you keep inserting new entries on the table, but won't remove and free those you don't need anymore, it can grow indefinitely, leaking heap memory event if th...