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SQL Group By with an Order By
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In all versions of MySQL, simply alias the aggregate in the SELECT list, and order by the alias:
SELECT COUNT(id) AS theCount, `Tag` from `images-tags`
GROUP BY `Tag`
ORDER BY theCount DESC
LIMIT 20
share
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How do you use variables in a simple PostgreSQL script?
...c/sql-do.html )
DO $$
DECLARE v_List TEXT;
BEGIN
v_List := 'foobar' ;
SELECT *
FROM dbo.PubLists
WHERE Name = v_List;
-- ...
END $$;
Also you can get the last insert id:
DO $$
DECLARE lastid bigint;
BEGIN
INSERT INTO test (name) VALUES ('Test Name')
RETURNING id INTO lastid;
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The type or namespace name 'DbContext' could not be found [closed]
... @Chris Dickinson, right click on the References item in the project and select Add Reference.... Then in the .NET tab, select System.Data.Entity. And if you want to use NuGet, right click on the References item and then select Add Library Package Reference... and in the Online tab, search for Ent...
What are the differences between a clustered and a non-clustered index?
...than a clustered index
Both types of index will improve performance when select data with fields that use the index but will slow down update and insert operations.
Because of the slower insert and update clustered indexes should be set on a field that is normally incremental ie Id or Timestamp.
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Is “else if” a single keyword?
...s section on keywords.
The grammar in section 6.4 also makes this clear:
selection-statement:
if ( condition ) statement
if ( condition ) statement else statement
The if in else if is a statement following the else term. The section also says:
[...]The substatement in a selection-statement...
Which machine learning classifier to choose, in general? [closed]
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Model selection using cross validation may be what you need.
Cross validation
What you do is simply to split your dataset into k non-overlapping subsets (folds), train a model using k-1 folds and predict its performance using the...
A generic list of anonymous class
... okay cool, now we need an example of replacing the new {} lines with a select statement. var list = sourceList.Select( o => new { o.ModelId, ...
How do I view the SQL generated by the Entity Framework?
...e query = from x in appEntities
where x.id == 32
select x;
var sql = ((System.Data.Objects.ObjectQuery)query).ToTraceString();
or in EF6:
var sql = ((System.Data.Entity.Core.Objects.ObjectQuery)query)
.ToTraceString();
That will give you the SQL that was g...
Uniq by object attribute in Ruby
What's the most elegant way to select out objects in an array that are unique with respect to one or more attributes?
14 An...
Store select query's output in one array in postgres
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There are two ways. One is to aggregate:
SELECT array_agg(column_name::TEXT)
FROM information.schema.columns
WHERE table_name = 'aean'
The other is to use an array constructor:
SELECT ARRAY(
SELECT column_name
FROM information.schema.columns
WHERE table_name = ...