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IN vs OR in the SQL WHERE Clause
...hen dealing with big databases, which performs better, IN or OR in the SQL Where -clause?
6 Answers
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What's the difference between NOT EXISTS vs. NOT IN vs. LEFT JOIN WHERE IS NULL?
It seems to me that you can do the same thing in a SQL query using either NOT EXISTS, NOT IN, or LEFT JOIN WHERE IS NULL. For example:
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How long should SQL email fields be? [duplicate]
...I don't see nvarchar anywhere... do I need to set that up manually with an SQL statement, or am I just missing it somewhere?
– Mala
Aug 19 '09 at 1:50
11
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Check if SQL Connection is Open or Closed
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You should be using SqlConnection.State
e.g,
using System.Data;
if (myConnection != null && myConnection.State == ConnectionState.Closed)
{
// do something
// ...
}
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2015互联网结束补贴战 从相杀到相爱只需一个长假 - 资讯 - 清泛网 - 专注C/...
...赶集网、美团和大众点评、携程和去哪儿、滴滴和快的，包括此前的优酷和土豆，就会发现，它们的共同点就是“烧钱”。因此如果要想预测下一个合并会是哪两个公司的话，只需要去找哪个领域目前是最烧钱的。所有的这些最...
SQL, Postgres OIDs, What are they and why are they useful?
I am looking at some PostgreSQL table creation and I stumbled upon this:
4 Answers
4
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Entity Framework 4 vs NHibernate [closed]
...apping, better integration with stored procs / database functions / custom SQL / triggers, support for formula properties and so on. IMO it's basically just more mature as an ORM.
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sqlalchemy IS NOT NULL select
How can I add the filter as in SQL to select values that are NOT NULL from a certain column ?
3 Answers
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Using MySQL with Entity Framework [closed]
Can't find anything relevant about Entity Framework/MySQL on Google so I'm hoping someone knows about it.
10 Answers
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Oracle: If Table Exists
...s for an Oracle database, and was hoping Oracle had something similar to MySQL's IF EXISTS construct.
15 Answers
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