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MySQL DISTINCT on a GROUP_CONCAT()
....new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f3083499%2fmysql-distinct-on-a-group-concat%23new-answer', 'question_page');
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Post as a guest
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SQL update from one Table to another based on a ID match
...INNER JOIN
RetrieveAccountNumber RAN
ON
SI.LeadID = RAN.LeadID;
MySQL and MariaDB
UPDATE
Sales_Import SI,
RetrieveAccountNumber RAN
SET
SI.AccountNumber = RAN.AccountNumber
WHERE
SI.LeadID = RAN.LeadID;
...
linux内存cached释放 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...缩短了 I/O系统调用(比如read,write,getdents)的时间。"
如何解决这个导致机器变慢的问题呢？
罪魁祸首就是内存都被cached了，free的基本没有了
所以我们应该想想如何把cached内存释放出来
重启机器肯定是可以解决，但是我们...
Possible to perform cross-database queries with PostgreSQL?
...
If you're coming from a MySQL environment, what MySQL calls databases are really schemas (CREATE SCHEMA == CREATE DATABASE in MySQL), so if you porting something from MySQL using multiple databases, use schemas
– MkV
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How does “do something OR DIE()” work in PHP?
I'm writing a php app to access a MySQL database, and on a tutorial, it says something of the form
4 Answers
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Efficient SQL test query or validation query that will work across all (or most) databases
...it of research along with help from some of the answers here:
SELECT 1
H2
MySQL
Microsoft SQL Server (according to NimChimpsky)
PostgreSQL
SQLite
SELECT 1 FROM DUAL
Oracle
SELECT 1 FROM any_existing_table WHERE 1=0
or
SELECT 1 FROM INFORMATION_SCHEMA.SYSTEM_USERS
or
CALL NOW()
HSQLDB (tested ...
How can I convert bigint (UNIX timestamp) to datetime in SQL Server?
...our code must match the casing! Another point could be that your System is MySql, than the name is date_add(). Regards ;)
– Nightking
Feb 11 '17 at 10:15
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Increment a database field by 1
With MySQL, if I have a field, of say logins, how would I go about updating that field by 1 within a sql command?
5 Answers...
传感器组件 · App Inventor 2 中文网
...步骤是看起来涉及向前运动的步骤。
方法
复位()
重置计步器、距离测量和跑步时间。
保存()
将计步器状态保存至手机。允许累积步数和调用使用计步器的应用程序之间的距离。不同的应用程序将有自己的保存状态。
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Overriding id on create in ActiveRecord
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Perhaps what I experienced only expressed itself with mysql driver.
– jkndrkn
Feb 18 '13 at 19:30
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