Count That Day Lost

Count that day lost

If you sit down at set of sun,

And count the acts that you have done,

And counting, find                   

One self-denying deed, one word,

That eased the heart of him who heard,

One glance most kind,

That fell like sunshine where it went --

Then you may count that day well spent,

But if through all the livelong day,

You’ve cheered no heart, by yea or nay --

If, through it all

You’ve nothing done that you can trace,

That brought the sunshine to one face -- No act most small.

Then count that day as worse than lost.

PHP array_merge array_diff array_intersect function c# alternative

If you've got LINQ available to you, you can use Union, Except, Intersect, and Distinct:

  • array1.Union(array2).Distinct().ToList()
  • array2.Except(array1)
  • array1.Except(array2)
  • array1.Intersect(array2)

Reference

MySQL: Delete All Duplicate Rows Except the Earliest One in One SQL

You want to add a unique index to a table, and unfortunately, there are already many duplicate rows in it. Manually find and delete these rows is time-wasting and error-prone. So why won't we just write one SQL statement and quickly resolve it?

First try, I wrote the following statement, and it won't work:

DELETE FROM PromotionSkus A 
WHERE 
	A.SkuId IN (SELECT SkuId FROM PromotionSkus B GROUP BY B.SkuId HAVING COUNT(B.SkuId) > 1) 
	AND 
	A.Id NOT IN (SELECT MIN(Id) FROM PromotionSkus C GROUP BY C.SkuId HAVING COUNT(C.SkuId) > 1);

AND this one below works!

DELETE FROM PromotionSkus A
WHERE 
	A.Id NOT IN (SELECT Id FROM (SELECT MIN(Id) AS Id, COUNT(SkuId) AS Total FROM PromotionSkus GROUP BY SkuId HAVING Total > 1) AS B)
	AND 
	A.SkuId IN (SELECT SkuId FROM (SELECT SkuId FROM PromotionSkus GROUP BY SkuId HAVING COUNT(SkuId) > 1) AS C);

The reason is well explained in this brilliant article.

However, I found a much simpler solution on 23-Mar-2025, which is

DELETE FROM PromotionSkus 
WHERE Id NOT IN (
    SELECT Id FROM (
        SELECT MIN(Id) AS Id 
        FROM PromotionSkus 
        GROUP BY SkuId
    ) A
);

Another mysql tip: using mysqldump export a table with one line one row.

mysqldump --databases YourDataBaseName --tables YourTableName --skip-extended-insert

Why do we need that? It is much easier to compare !

.NET Core 3.1 Swagger UI Tweaks

  1. Present enums as string. Modify your StartUp.cs, add the highlight part below:
            services.AddMemoryCache().AddMvcCore().AddJsonOptions(opts =>
                {
                    opts.JsonSerializerOptions.Converters.Add(new JsonStringEnumConverter());
                })
                .AddDataAnnotationsLocalization();

  1. Enable XML Comments

    1. Manually add the two lines in PropertyGroup below to the .csproj file:
<PropertyGroup>
  <GenerateDocumentationFile>true</GenerateDocumentationFile>
  <NoWarn>$(NoWarn);1591</NoWarn>
</PropertyGroup>

2. Add the options in the code below 

            services.AddSwaggerGen(options =>
            {
                options.IncludeXmlComments(Path.Combine(AppDomain.CurrentDomain.BaseDirectory, $"{AppDomain.CurrentDomain.FriendlyName}.xml"), true);
            });

SQLSugar: How to implement Count(FieldName) and GROUP BY in SQLSugar 

            await Db.Queryable<Entity>().Where(_ => _.SampleFieldName== sampleFieldValue)
                .GroupBy("AnothterFieldNameInStringFormat")
                .Select<ResultModel>("AnotherFieldNameInStringFormat, Count(AnotherFieldNameInStringFormat) Total")
                .ToListAsync();