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When to use a key/value store such as Redis instead/along side of a SQL database?

.... I did recently for one gps tracking system which was previously built on mysql as a database. ADVANTAGE Every time the tracker broadcast data I do not need to open mysql connection and store on it. We can save it on redis and later migrate to mysql using some other process. This will avoid conc...
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How to implement LIMIT with SQL Server?

I have this query with MySQL: 18 Answers 18 ...
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setting multiple column using one update

How to set multiple columns of a table using update query in mysql? 2 Answers 2 ...
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How can I transform string to UTF-8 in C#?

... If you want to save any string to mysql database do this:-> Your database field structure i phpmyadmin [ or any other control panel] should set to utf8-gerneral-ci 2) you should change your string [Ex. textbox1.text] to byte, therefor 2-1) define byte[]...
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Null vs. False vs. 0 in PHP

...or a data value that doesn't exist in the database or is unknown. See dev.mysql.com/doc/refman/5.0/en/working-with-null.html or en.wikipedia.org/wiki/Null_%28SQL%29. – Eli Dec 5 '12 at 3:39 ...
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App Inventor 2 低功耗蓝牙 BlueToothLE 拓展 · App Inventor 2 中文网

... Disconnect 或 DisconnectWithAddress 引起的,或者在设备移开或重置以致发生连接丢失后引起的。 FloatsReceived – 当从连接的蓝牙设备接收到一个或多个 IEEE 754 浮点值时,将触发该事件。根据上次调用 ReadFloats 或 RegisterForFlo...
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How to change a nullable column to not nullable in a Rails migration?

... This worked for me. Using MySql locally. When pushed and ran app in Heroku (Postgres) it crapped on column that was not null when I was writing it a null - rightfully so. Only "change_column_null" would work could not use "change_column ... :null =&gt...
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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...
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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...
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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. share | improve this answer | ...