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mysql update column with value from another table
I have two tables, both looking like
8 Answers
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Using DISTINCT and COUNT together in a MySQL Query
Is something like this possible:
7 Answers
7
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How to get root access on Android emulator?
...roid SDK versions(from 1.5 to 2.3.3), and I tried many methods for getting root in Android emulator. I don't use any Android device and test everything on emulator(AVD).
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What is the difference between single and double quotes in SQL?
...ct_id
SELECT PRODUCT.id 'product_id'
Either works in Oracle, SQL Server, MySQL… but I know some have said that the TOAD IDE seems to give some grief when using the single quotes approach.
You do have to use single quotes when the column alias includes a space character, e.g., product id, but it...
MongoDB or CouchDB - fit for production? [closed]
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We are running CouchDB as a replacemant for MySQL for our shops (70.0000 items/shop, a total of 4 million attributes of all items, cross connections between items).
Our goals were:
Easy replication from a master-db to several clients with different documents.
Fast p...
How to get ER model of database from server with Workbench
...y to get an ER model of a database from the server that is connected to my MySQL Workbench?
4 Answers
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MySQL, better to insert NULL or empty string?
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Better to Insert NULL for consistency in your database in MySQL. Foreign keys can be stored as NULL but NOT as empty strings.
You will have issues with an empty string in the constraints.
You may have to insert a fake record with a unique empty string to satisfy a Foreign Key cons...
boost多索引容器multi_index_container实战 - C/C++ - 清泛网 - 专注C/C++及内核技术
...些知识有过了解
什么是多索引容器？为什么要使用它？如何使用？
接下来一一回答以上的问题。
想必大家在实际开发中一定多多少少会遇到以下的问题，我需要创建一个map，并且需要两种方式去索引，比如：创建一个<学号,...
How to work with complex numbers in C?
...introduced in mathematics, from the need of calculating negative quadratic roots. Complex number concept was taken by a variety of engineering fields.
Today that complex numbers are widely used in advanced engineering domains such as physics, electronics, mechanics, astronomy, etc...
Real and imag...
Delete directory with files in it?
...ting /, this would only work if you'd lounch the script in command line as root, because in web everything happens as apache user
– Ben
Jun 27 '14 at 9:40
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