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What is the difference between a schema and a table and a database?
...ion of tables. A DBMS (Database Management System) is the software (like MySQL, SQL Server, Oracle, etc) that manages and runs a database.
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XMLHttpRequest Origin null is not allowed Access-Control-Allow-Origin for file:/// to file:/// (Serv
...eeded in a separate javascript file instead. (In my case I needed a binary SQLite blob to use with https://github.com/kripken/sql.js/)
I created a file called base64_data.js (and used btoa() to convert the data that I needed and insert it into a <div> so I could copy it).
var base64_data = "...
Where are my postgres *.conf files?
I have recently reinstalled postgresql 8.3 on my Ubuntu 8.04 after update. Used EnterpriseDB package. I can connect to the database locally, I see system DB postgres but I can't configure it because I can't find config files. Searched through entire hard drive and found only samples like pg_hba.con...
What is the Java equivalent for LINQ? [closed]
...s trying to port LINQ to Java are implementations for a concrete scenario (SQL, Objects...) but does not covr the main goal of LINQ: Integrate the Language Query in the code. Due to this, there is no real alternative nor initative, for now, that can be considered as an alternative.
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Find() vs. Where().FirstOrDefault()
...nd makes use of the primary keys (hence indexes), whereas Where is a plain sql query
– percebus
Feb 9 '16 at 19:56
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When to use SELECT … FOR UPDATE?
...ds on the concurrency control your database system is using.
MyISAM in MySQL (and several other old systems) does lock the whole table for the duration of a query.
In SQL Server, SELECT queries place shared locks on the records / pages / tables they have examined, while DML queries place update lo...
How to access a dictionary element in a Django template?
...de in your templates and vice-versa.
I'd try the above method and see what SQL the ORM generates as I'm not sure off the top of my head if it will pre-cache the properties and just create a subselect for the property or if it will iteratively / on-demand run the query to calculate vote count. But if...
关于php的socket初探 - PHP - 清泛IT论坛，有思想、有深度
...些多路复用的模式中，异步阻塞/非阻塞模式的扩展性和性能最好。
引入阻塞/非阻塞,、同步/异步比喻很形象的一段话：
有A，B，C，D四个人在钓鱼：
A用的是最老式的鱼竿，所以呢，得一直守着，等到鱼上钩了再拉杆；
B的...
How to select all records from one table that do not exist in another table?
...in basically every database engine ever that attempts to implement ANSI 92 SQL
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Multiline string literal in C#
...whatever line break your source has them as) into the string, however. For SQL, that's not only harmless but probably improves the readability anywhere you see the string - but in other places it may not be required, in which case you'd either need to not use a multi-line verbatim string literal to ...