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How do I update if exists, insert if not (AKA “upsert” or “merge”) in MySQL?
...SERT a row when it does not exist, or to UPDATE if it exists, using one MySQL query?
2 Answers
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MySQL Creating tables with Foreign Keys giving errno: 150
I am trying to create a table in MySQL with two foreign keys, which reference the primary keys in 2 other tables, but I am getting an errno: 150 error and it will not create the table.
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Change One Cell's Data in mysql
How can I change the data in only one cell of a mysql table.
I have problem with UPDATE because it makes all the parameters in a column change but I want only one changed. How?
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“21天教你学会C++” - 创意 - 清泛网 - 专注C/C++及内核技术
...法（如果你已经会一门类似的语言），但你无法学到多少如何运用这些语法。简而言之，如果你是，比如说一个Basic程序员，你可以学会用C++语法写出Basic风格的程序，但你学不到C++真正的优点（和缺点）。那关键在哪里？Alan Per...
Where is a complete example of logging.config.dictConfig?
... # Default is stderr
},
},
'loggers': {
'': { # root logger
'handlers': ['default'],
'level': 'WARNING',
'propagate': False
},
'my.packg': {
'handlers': ['default'],
'level': 'INFO',
'...
select into in mysql
I am a MSSQL user and now I am converting my database to MySQL. I am writing the following query in MySQL:
2 Answers
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Query to count the number of tables I have in MySQL
...long wait time. In that case, login should be done with the option -A, ie: mysql -uroot -p -A, and the command will work fast.
– azurecorn
Jul 21 at 12:28
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Remove duplicate rows in MySQL
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This is no longer support in 5.7.4, dev.mysql.com/doc/refman/5.7/en/alter-table.html
– Ray Baxter
Nov 25 '15 at 20:59
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Get records with max value for each group of grouped SQL results
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There's a super-simple way to do this in mysql:
select *
from (select * from mytable order by `Group`, age desc, Person) x
group by `Group`
This works because in mysql you're allowed to not aggregate non-group-by columns, in which case mysql just returns the first...
Difference between VARCHAR and TEXT in MySQL [duplicate]
When we create a table in MySQL with a VARCHAR column, we have to set the length for it. But for TEXT type we don't have to provide the length.
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