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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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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.
...
Sublime Text 3能用支持的插件推荐 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...方法不管用，可以看看我之前写的一篇文章，Sublime text 3如何安装package control办法。
此外，安装sublime text 3的插件还可以在github上下载源文件，解压后改名放到
C:\Users\Mr.DenGo(你的电脑名)\AppData\Roaming\Sublime Text 3\Packages 中
重启su...
INNER JOIN ON vs WHERE clause
....
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.
...
How to get multiple counts with one SQL query?
... entire nested query with a simple count(*) as @Mihai shows - with further MySQL only syntax simplifications.
– YoYo
Apr 1 '17 at 19:29
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Setting up foreign keys in phpMyAdmin?
...dmin lets you define foreign keys using their "relations" view. But since, MySQL only supports foreign constraints on "INNO DB" tables, the first step is to make sure the tables you are using are of that type.
To setup a foreign key so that the PID column in a table named CHILD references the ID co...