大约有 9,000 项符合查询结果（耗时：0.0230秒） [XML]
How can I rename a database column in a Ruby on Rails migration?
...oing one row at a time. The migration would execute much faster with raw sql statements to update correctly named columns. For example, in the first db migration script, after adding the duplicate column names, execute "Update table_name set correct_name_column_one = old_name_column_one"
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MySQL: Set user variable from result of query
Is it possible to set an user variable based on the result of a query in MySQL?
4 Answers
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What should every programmer know about security? [closed]
...browser ID field as 'user input' but it can just as easily contain, say, a SQL injection.
– Peteris
May 7 '12 at 17:49
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Count the occurrences of DISTINCT values
I am trying to find a MySQL query that will find DISTINCT values in a particular field, count the number of occurrences of that value and then order the results by the count.
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How to combine two or more querysets in a Django view?
...e:
union()
union(*other_qs, all=False)
New in Django 1.11. Uses SQL’s UNION operator to combine the results of two or more QuerySets. For example:
>>> qs1.union(qs2, qs3)
The UNION operator selects only distinct values by default. To allow duplicate values, use the all=T...
how to customize `show processlist` in mysql?
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Newer versions of SQL support the process list in information_schema:
SELECT * FROM INFORMATION_SCHEMA.PROCESSLIST
You can ORDER BY in any way you like.
The INFORMATION_SCHEMA.PROCESSLIST table was added in MySQL 5.1.7. You can find out...
How to calculate age (in years) based on Date of Birth and getDate()
... The simplest/shortest code for this exact same calculation method in SQL Server 2012+ is code: SELECT [Age] = (0+ FORMAT(@as_of,'yyyyMMdd') - FORMAT(@bday,'yyyyMMdd') ) /10000 --The 0+ part tells SQL to calc the char(8) as numbers
– ukgav
Mar 4 '19 at ...
Worst security hole you've seen? [closed]
...ng how many pages on the Internet, government sites in particular, pass an SQL query through the query string. It's the worst form of SQL injection, and it takes no effort at all to find vulnerable sites.
With minor tweaks, I've been able to find unprotected installations of phpMyAdmin, unprotected...
Git command to show which specific files are ignored by .gitignore
... first show me 4 files, and the second only two. (.gitignore~, index.php~, sql/create_users.sql~, www/index.php~) (Would remove .gitignore~, Would remove index.php~). Am I missins something here?
– Cesar
Jun 15 '11 at 21:00
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List columns with indexes in PostgreSQL
I would like to get the columns that an index is on in PostgreSQL.
23 Answers
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