大约有 47,000 项符合查询结果（耗时：0.0349秒） [XML]
How to sort the result from string_agg()
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With postgres 9.0+ you can write:
select string_agg(product,' | ' order by product) from "tblproducts"
Details here.
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how to check the dtype of a column in python pandas
...know this is a bit of an old thread but with pandas 19.02, you can do:
df.select_dtypes(include=['float64']).apply(your_function)
df.select_dtypes(exclude=['string','object']).apply(your_other_function)
http://pandas.pydata.org/pandas-docs/version/0.19.2/generated/pandas.DataFrame.select_dtypes.h...
How to delete an old/unused Data Model Version in Xcode
... model version were re-sorted improperly and the wrong default version was selected as I re-added the xcdatamodel file into the project. This may be because I am up to 38 model versions and I haven't changed the default version name, so the versions are named "MY_APP 37.xcdatamodel". I wanted to del...
Export Postgresql table data using pgAdmin
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Just right click on a table and select "backup". The popup will show various options, including "Format", select "plain" and you get plain SQL.
pgAdmin is just using pg_dump to create the dump, also when you want plain SQL.
It uses something like this: ...
Copy existing project with a new name in Android Studio
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I've selected the base package folder and clicked Refactor -> Rename, I got errors with "package rename" option, then I did "folder rename" option with success.
– Ismail Yavuz
May 23 '19 a...
Two single-column indexes vs one two-column index in MySQL?
... the statement I provided.
Additionally, MySQL can only use one index per SELECT so a covering index would be the best means of optimizing your queries.
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A circular reference was detected while serializing an object of type 'SubSonic.Schema .DatabaseColu
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I think maybe selecting the ones I want may work I think the circular reference is because in Event I have IQueryable<Category> which in turn will have a IQueryable<Event>
– Jon
Jul 20 '09...
How should one use std::optional?
...at are provided purely to enforce intention) include the various C++ style casts, "const" (especially on member functions), and the "bool" type, to name a few. Arguably you don't really need these code features, so long as everyone obeys intentions or comments.
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SQL- Ignore case while searching for a string
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Use something like this -
SELECT DISTINCT COL_NAME FROM myTable WHERE UPPER(COL_NAME) LIKE UPPER('%PriceOrder%')
or
SELECT DISTINCT COL_NAME FROM myTable WHERE LOWER(COL_NAME) LIKE LOWER('%PriceOrder%')
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How to check if mysql database exists
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SELECT SCHEMA_NAME
FROM INFORMATION_SCHEMA.SCHEMATA
WHERE SCHEMA_NAME = 'DBName'
If you just need to know if a db exists so you won't get an error when you try to create it, simply use (From here):
CREATE DATABASE IF NO...