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Sync data between Android App and webserver [closed]
...logic for database like: How to sync SQLite database on Android phone with MySQL database on server?
Best Luck to all new learner. :)
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SQL query to group by day
... (from Q8-Coder):
GROUP BY dateadd(DAY,0, datediff(day,0, created))
For MySQL:
GROUP BY year(datefield), month(datefield), day(datefield)
or better (from Jon Bright):
GROUP BY date(datefield)
For Oracle:
GROUP BY to_char(datefield, 'yyyy-mm-dd')
or faster (from IronGoofy):
GROUP BY trun...
Update a column value, replacing part of a string
I have a table with the following columns in a MySQL database
6 Answers
6
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Reason for Column is invalid in the select list because it is not contained in either an aggregate f
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@davidblaine, MySQL has a function GROUP_CONCAT() for that. dev.mysql.com/doc/refman/5.5/en/… But in standard SQL, each column should contain only one value. That's fundamental to relational theory too.
– Bill Kar...
How to do 3 table JOIN in UPDATE query?
...need a visual aid to get your joins correct: browse-tutorials.com/tutorial/mysql-joins-visual-representation
– ram4nd
Jan 27 '17 at 9:29
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What is the simplest SQL Query to find the second largest value?
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I see both some SQL Server specific and some MySQL specific solutions here, so you might want to clarify which database you need. Though if I had to guess I'd say SQL Server since this is trivial in MySQL.
I also see some solutions that won't work because they fail to...
Format number to 2 decimal places
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You want to use the TRUNCATE command.
https://dev.mysql.com/doc/refman/8.0/en/mathematical-functions.html#function_truncate
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How to select the nth row in a SQL database table?
... http://troels.arvin.dk/db/rdbms/#select-limit.
Basically, PostgreSQL and MySQL supports the non-standard:
SELECT...
LIMIT y OFFSET x
Oracle, DB2 and MSSQL supports the standard windowing functions:
SELECT * FROM (
SELECT
ROW_NUMBER() OVER (ORDER BY key ASC) AS rownumber,
columns
F...
INSERT INTO … SELECT FROM … ON DUPLICATE KEY UPDATE
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MySQL will assume the part before the equals references the columns named in the INSERT INTO clause, and the second part references the SELECT columns.
INSERT INTO lee(exp_id, created_by, location, animal, starttime, endtime...
13 种激励程序员的方法 - 创意 - 清泛网 - 专注C/C++及内核技术
...导者应该确定最终的目的和目标，并授权技术人员弄清楚如何最好地实现。
10.简化和优化
程序员希望完成工作，而完成工作所需工具过多则会使进展缓慢、繁琐或者融合不好。同样的，官僚的作风不但不会增加价值，反而会...