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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...
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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大数据能否拯救中国足球? - 资讯 - 清泛网 - 专注C/C++及内核技术
...难。
未来大数据在足球相关产业中的应用前景到底如何?从球队、球员的日常训练到整个职业联赛球员大数据库的建立,从可穿戴设备到体育赛事转播的制作包装,大数据可介入的发力点又在哪里?
事实上,随着80亿中超(...
Getting the minimum of two values in SQL
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For MySQL or PostgreSQL 9.3+, a better way is to use the LEAST and GREATEST functions.
SELECT GREATEST(A.date0, B.date0) AS date0,
LEAST(A.date1, B.date1, B.date2) AS date1
FROM A, B
WHERE B.x = A.x
With:
GREATEST(v...
Possible to perform cross-database queries with PostgreSQL?
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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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Unicode与UTF-8互转(C语言实现) - C/C++ - 清泛网 - 专注C/C++及内核技术
...了符号的二进制代码, 却没有规定这
个二进制代码应该如何存储".
比如, 汉字"严"的unicode是十六进制数4E25, 转换成二进制数足足有15位
(100111000100101), 也就是说这个符号的表示至少需要2个字节. 表示其他更大的符号,
可能需要3...
大数据:用数据指导APP运营 - 资讯 - 清泛网 - 专注C/C++及内核技术
...感觉在不知不觉中获得了提升,这一点,非常重要。
3 如何获取数据
获取数据的渠道有很多,而方式基本就是自己做和使用外部工具两种方式。
自己做的话,App可以选择“埋点”、log等方式,而Web可以通过log、日志与按钮埋...
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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SQL select only rows with max value on a column [duplicate]
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I know that MySQL allows you to add non aggregate fields to a "grouped by" query, but I find that kinda pointless. Try running this select id, max(rev), rev from YourTable group by id and you see what I mean. Take your time and try to un...
How to test an SQL Update statement before running it?
...What about Transactions? They have the ROLLBACK-Feature.
@see https://dev.mysql.com/doc/refman/5.0/en/commit.html
For example:
START TRANSACTION;
SELECT * FROM nicetable WHERE somthing=1;
UPDATE nicetable SET nicefield='VALUE' WHERE somthing=1;
SELECT * FROM nicetable WHERE somthing=1; #check
CO...