大约有 40,000 项符合查询结果（耗时：0.0237秒） [XML]
How do I find which transaction is causing a “Waiting for table metadata lock” state?
I am trying to perform some DDL on a table and SHOW PROCESSLIST results in a " Waiting for table metadata lock " message.
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How should you build your database from source control?
...sing automation - or should production by built by copying objects from a stable, finalized test environment?
Automation for both. Do NOT copy data between the environments
How do you deal with potential differences between test and production environments in deployment scripts?
Use templates, so th...
MySQL Conditional Insert
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If your DBMS does not impose limitations on which table you select from when you execute an insert, try:
INSERT INTO x_table(instance, user, item)
SELECT 919191, 123, 456
FROM dual
WHERE NOT EXISTS (SELECT * FROM x_table
WHE...
How can I tell when a MySQL table was last updated?
...updated the xx/xx/200x" with this date being the last time a certain mySQL table has been updated.
15 Answers
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Converting string from snake_case to CamelCase in Ruby
...ring:
"AppUser".underscore # => "app_user"
or, if you want to get the table name, which is probably why you'd want the snake case:
AppUser.name.tableize # => "app_users"
share
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improve thi...
Django filter queryset __in for *every* item in list
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This would we slower if you work with large tables and large data to compare to. (like 1 Million each)
– gies0r
May 21 '18 at 16:11
1
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Store query result in a variable using in PL/pgSQL
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I think you're looking for SELECT INTO:
select test_table.name into name from test_table where id = x;
That will pull the name from test_table where id is your function's argument and leave it in the name variable. Don't leave out the table name prefix on test_table.name or ...
Is it possible to break a long line to multiple lines in Python [duplicate]
...t a list of strings instead of one long string:
queryText= "SELECT * FROM TABLE1 AS T1"\
"JOIN TABLE2 AS T2 ON T1.SOMETHING = T2.SOMETHING"\
"JOIN TABLE3 AS T3 ON T3.SOMETHING = T2.SOMETHING"\
"WHERE SOMETHING BETWEEN <WHATEVER> AND <WHATEVER ELSE>"\
"ORDER BY WHATEVERS DESC"
kinda li...
Why do Twitter Bootstrap tables always have 100% width?
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All tables within the bootstrap stretch according to their container, which you can easily do by placing your table inside a .span* grid element of your choice. If you wish to remove this property you can create your own table cl...
COUNT(*) vs. COUNT(1) vs. COUNT(pk): which is better? [duplicate]
...OUNT(*), and stick with it consistently, and if your database allows COUNT(tableHere) or COUNT(tableHere.*), use that.
In short, don't use COUNT(1) for anything. It's a one-trick pony, which rarely does what you want, and in those rare cases is equivalent to count(*)
Use count(*) for counting
U...