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Is there a MySQL option/feature to track history of changes to records?
...ary_key_column as 'row id',
IF(t1.a_column = t2.a_column, t1.a_column, CONCAT(t1.a_column, " to ", t2.a_column)) as a_column
FROM MyDB.data_history as t1 INNER join MyDB.data_history as t2 on t1.primary_key_column = t2.primary_key_column
WHERE (t1.revision = 1 AND t2.revision = 1) OR t2.r...
Questions every good .NET developer should be able to answer? [closed]
...te where people are trying to roll their own version of Union Distinct and Concat for collections because they don't understand LINQ.
– Evan Plaice
Jun 19 '10 at 1:04
...
What's the difference(s) between .ToList(), .AsEnumerable(), AsQueryable()?
...al joins where a certain Column that is calculated on the view for example concat(t1.colA, t2.colB, t2.colC) as MyVeryNeetColumn (i know its a stupid example, but could be anything). When you do a Where on that column in it will have horrible times because the db needs to calculate all vals to perfo...
how to draw smooth curve through N points using javascript HTML5 canvas?
... for (var i = 0; i < pts.length - 2; i += 1) {
cps = cps.concat(ctlpts(pts[2*i], pts[2*i+1],
pts[2*i+2], pts[2*i+3],
pts[2*i+4], pts[2*i+5]));
}
if ($("showControlLines").check...
Fast permutation -> number -> permutation mapping algorithms
...Position[i], iOutPosition[i] + 1);
this.sOutStr = this.sOutStr.concat(sTempStr);
}
return this.sOutStr;
}
public int[] PermGetIntArray(int iIndex)
{
if (!this.bGoodToGo) return null;
if (!this.PermEvaluate(iIndex)) return null ;
return...
Comparison of full text search engine - Lucene, Sphinx, Postgresql, MySQL?
...ss"/>
<document>
<entity name="test_solr" query="select CONCAT('test_solr-',id) as rid,name from test_solr_mysql WHERE '${dataimporter.request.clean}' != 'false'
OR `created` > '${dataimporter.last_index_time}'" >
<field name="id" column="rid" />
<fiel...
How to make good reproducible pandas examples
... {0: 'aapl', 1: 'aapl', 2: 'aapl', 3: 'aapl', 4: 'aapl'}}
>>> pd.concat([stocks.head(), stocks.tail()], ignore_index=True).to_dict()
{'date': {0: Timestamp('2011-01-01 00:00:00'),
1: Timestamp('2011-01-01 00:00:00'),
2: Timestamp('2011-01-01 00:00:00'),
3: Timestamp('2011-01-01 00:00...
SQL Server query to find all permissions/access for all users in a database
...) WHEN 'SCHEMA' THEN SCHEMA_NAME(dp.major_id) WHEN 'OBJECT_OR_COLUMN' THEN CONCAT_WS('.', OBJECT_SCHEMA_NAME(dp.major_id), OBJECT_NAME(dp.major_id), c.[name]) END FROM sys.database_principals AS p LEFT OUTER JOIN sys.database_permissions AS dp ON p.principal_id = dp.grantee_principal_id LEFT OUTER J...
ReactJS Two components communicating
...; i <= this.state.numOfDays; i++) {
dayNodes = dayNodes.concat([<DayNumber dayNum={i} />]);
}
return (
<select id={this.props.id} onChange = {this.handleDaySelection}>
<option value="" disabled defaultValue...
What does “coalgebra” mean in the context of programming?
... structure. Here's a nice article helping explain the idea. It talks about concat, which is just join for lists.
With Haskell functors, the composition of two functors is a functor itself. In pseudocode, we could write this:
instance (Functor f, Functor g) ⇒ Functor (f ∘ g) where
fmap fun x ...