Tags » SQL

DataFrames and SQL

SQL DataFrame (Scala) SELECT col_1 FROM myTable df.select($"col_1") DESCRIBE myTable df.printSchema SELECT * FROM myTable WHERE col_1 > 0 df.filter($"col_1" > 0) ..GROUP BY col_2… 27 more words

How I Refactored My ExpressJS Code(A Chat App)

Refactoring is something every programmer has to do once in a while. You start to write something. You search around to find out how everything works and piece them together in your program. 1,851 more words

Coding Tutorial

Big Data, A Long Introduction

One of my colleagues from the Business Operation texted me on one morning and asked me where she can get insights, understand some of the terminology, difference between the SQL and NoSQL, and how to make decision which type of database to be used. 982 more words

Experience Sharing

Troubleshooting SSMS Error: 15517

If you meet with the same error as me in SSMS 2016.


“Cannot execute as the database principal because the principal “dbo” does not exist, this type of principal cannot be impersonated, or you do not have permission (Microsoft SQL Server, Error: 15517)” 43 more words


Diseño de Base de Datos, parte X: Funciones

Las funciones prefabricadas de SQL nos permiten realizar múltiples operaciones en nuestros scripts: Desde poner en mayúsculas o minúsculas el resultado de un campo, hasta asignar fechas o validar si un campo es NULL. 225 more words


Setup SQL Server Connection Resiliency with Entity Framework

Tested on:
Microsoft SQL Server 13.00.5292
Entity Framework 6.2.0

When an application execute too many operations against SQL Server, a transient fault could occur.
Transient fault in SQL Server could occurred in self-hosted or cloud SQL Server. 171 more words