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how to exclude null values in array_agg like in string_agg using postgres?
...
SQL Fiddle
select
id,
(select array_agg(a) from unnest(canonical_users) a where a is not null) canonical_users,
(select array_agg(a) from unnest(non_canonical_users) a where a is not null) non_canonical_users
from (
SELE...
How to search a specific value in all tables (PostgreSQL)?
... If you're using IntelliJ you can just right-click your db and select "Dump with 'pg_dump'" or "Dump data to file(s)"
– Laurens
Nov 29 '17 at 12:26
3
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MySQL ON vs USING?
...n tables ON a column, a set of columns and even a condition. For example:
SELECT * FROM world.City JOIN world.Country ON (City.CountryCode = Country.Code) WHERE ...
USING is useful when both tables share a column of the exact same name on which they join. In this case, one may say:
SELECT ... FR...
如何查看Oracle用户的SQL执行历史记录？ - 数据库(内核) - 清泛网 - 专注C/...
如何查看Oracle用户的SQL执行历史记录？select * from v$sqlarea t order by t LAST_ACTIVE_TIME desc注意 ：执行此语句等等一些相关的语句 必须具有DBA 的权限 虽然
select * from v$sqlarea t order by t.LAST_ACTIVE_TIME desc
注意 ：执行此语句等等一些相...
How do I do top 1 in Oracle?
...
If you want just a first selected row, you can:
select fname from MyTbl where rownum = 1
You can also use analytic functions to order and take the top x:
select max(fname) over (rank() order by some_factor) from MyTbl
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Retrieving the last record in each group - MySQL
...x, we can write greatest-n-per-group queries:
WITH ranked_messages AS (
SELECT m.*, ROW_NUMBER() OVER (PARTITION BY name ORDER BY id DESC) AS rn
FROM messages AS m
)
SELECT * FROM ranked_messages WHERE rn = 1;
Below is the original answer I wrote for this question in 2009:
I write the solu...
PostgreSQL Crosstab Query
... - not fit for missing attributes
crosstab(text) with 1 input parameter:
SELECT *
FROM crosstab(
'SELECT section, status, ct
FROM tbl
ORDER BY 1,2' -- needs to be "ORDER BY 1,2" here
) AS ct ("Section" text, "Active" int, "Inactive" int);
Returns:
Section | Active | Inacti...
How to add MVC5 to Visual Studio 2013?
...onger has separate project types for different ASP.Net features.
You must select .NET Framework 4.5 (or higher) in order to see the ASP.NET Web Application template (For ASP.NET One).
So just select Visual C# > Web > ASP.NET Web Application, then select the MVC checkbox in the next step.
Not...
SELECT * FROM X WHERE id IN (…) with Dapper ORM
...
Dapper supports this directly. For example...
string sql = "SELECT * FROM SomeTable WHERE id IN @ids"
var results = conn.Query(sql, new { ids = new[] { 1, 2, 3, 4, 5 }});
share
|
imp...
Copying text outside of Vim with set mouse=a enabled
...
Press shift while selecting with the mouse. This will make mouse selection behave as if mouse=a was not enabled.
Note: this trick also applies to "middle button paste": if you want to paste in vim text that was selected outside, press shift w...