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MySQL/SQL: Group by date only on a Datetime column
Having a table with a column like: mydate DATETIME ...
4 Answers
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Is there a way to access the “previous row” value in a SELECT statement?
I need to calculate the difference of a column between two lines of a table. Is there any way I can do this directly in SQL? I'm using Microsoft SQL Server 2008.
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How can I prevent SQL injection in PHP?
...ng "'Sarah'; DELETE FROM employees", and you will not end up with an empty table.
Another benefit of using prepared statements is that if you execute the same statement many times in the same session it will only be parsed and compiled once, giving you some speed gains.
Oh, and since you asked abo...
How do I convert from BLOB to TEXT in MySQL?
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Usage: SELECT CONVERT(column USING utf8) FROM table;
– bmaupin
Oct 2 '12 at 19:32
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Spring JPA selecting specific columns
...ase operations. However I don't know how to select specific columns from a table in Spring JPA?
14 Answers
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Practical uses of different data structures [closed]
...ound the list in a similar question, previously on StackOverflow:
Hash Table - used for fast data lookup - symbol table for compilers,
database indexing, caches,Unique data representation.
Trie - dictionary, such as one found on a mobile telephone for
autocompletion and spell-checking.
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LINQ-to-SQL vs stored procedures? [closed]
...umber of supported databases will only increase. Sprocs are not always portable between databases, either because of varying syntax or feature support (if the database supports sprocs at all).
Deployment: Others have mentioned this already, but it's easier to deploy a single assembly than to deploy...
Is having an 'OR' in an INNER JOIN condition a bad idea?
... to improve the speed of an immensely slow query (several minutes on two tables with only ~50,000 rows each, on SQL Server 2008 if it matters), I narrowed down the problem to an OR in my inner join, as in:
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Count work days between two dates
...their post, I just added holidays to the function (This assumes you have a table "tblHolidays" with a datetime field "HolDate".
--Changing current database to the Master database allows function to be shared by everyone.
USE MASTER
GO
--If the function already exists, drop it.
IF EXISTS
(
SEL...
Join vs. sub-query
...and query-specific.
Historically, explicit joins usually win, hence the established wisdom that joins are better, but optimisers are getting better all the time, and so I prefer to write queries first in a logically coherent way, and then restructure if performance constraints warrant this.
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