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Does a foreign key automatically create an index?
... I'm just about positive that PostgreSQL creates an index. I'm pretty sure MySQL does. Making the index makes a ton of sense, but IT'T NOT REQUIRED. After all, why reference something if every time the DB goes to look it up it has to do a tablescan?
– MBCook
Ma...
Getting the PublicKeyToken of .Net assemblies
...Pravat> ([system.reflection.assembly]::loadfile("C:\Program Files (x86)\MySQL\Connector NET 6.6.5\Assemblies\v4.0\MySql.Data.dll")).FullName
like
PS C:\Users\Pravat> ([system.reflection.assembly]::loadfile("dll full path")).FullName
and will appear like
MySql.Data, Version=6.6.5.0, Cu...
SQL - using alias in Group By
...OUP BY is executed before the SELECT clause.
There are exceptions though: MySQL and Postgres seem to have additional smartness that allows it.
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What's the longest possible worldwide phone number I should consider in SQL varchar(length) for phon
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I know that should be the case, but it's not always. In MySQL (for example) the full length is used for sorting. It's best to apply at least some minimal effort.
– Morgan Tocker
Jul 20 '10 at 18:23
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Cleanest way to build an SQL string in Java
...d MERGE. You can create SQL like this:
String sql1 = DSL.using(SQLDialect.MYSQL)
.select(A, B, C)
.from(MY_TABLE)
.where(A.equal(5))
.and(B.greaterThan(8))
.getSQL();
String sql2 = DSL.using(SQLDialect.MYSQL)
...
How to UPSERT (MERGE, INSERT … ON DUPLICATE UPDATE) in PostgreSQL?
... very frequently asked question here is how to do an upsert, which is what MySQL calls INSERT ... ON DUPLICATE UPDATE and the standard supports as part of the MERGE operation.
...
互联网健身的火爆：技术驱动是内因 资本只是点缀 - 资讯 - 清泛网 - 专注C/...
...网健身的创业者们来讲是亟待解决的问题。无论创业者们如何解决这些问题，“业余是细流，专业是大坝”这个基本的原则才是保证整个产品科学发展的关键因素。
改变四：比赛还是要打的，关键是怎么打
对于很多日常的健...
为什么说自媒体到了最危险的时期？ - 资讯 - 清泛网 - 专注C/C++及内核技术
...、资金等需求只是第一个层面的需求，更深层次的需求是如何找到适合自己的发展道路，平台不仅仅是输血，更多是要引导和一起探索。
目前能够做这件事情的，只有BAT。在现有BAT的布局中，阿里热衷于投资媒体，百度目前有...
INNER JOIN ON vs WHERE clause
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It's easier to see this with the WHERE syntax.
As for your example, in MySQL (and in SQL generally) these two queries are synonyms.
Also note that MySQL also has a STRAIGHT_JOIN clause.
Using this clause, you can control the JOIN order: which table is scanned in the outer loop and which one is...
Best way to do multi-row insert in Oracle?
...rform multi-row inserts into an Oracle 9 database. The following works in MySQL but doesn't seem to be supported in Oracle.
...