At present, the table structure of a question bank is designed, and one question will have subquestions, the amount of evaluation table data exceeds 10 million, SQL Server is used as storage. Question table contains question number, stem, type, explanation, answer and other attributes. what is the best way to design the schema in this… Read More How to design a data table with a parent-child relationship
I have a table Person. Id, Name, Phone ——————- 1, NULL, 123456789 This Person.Id is an auto increment identity. After a while, I found Name is useless for the current business and it always is NULL. So I deleted this column. Later, I found one person can have multiple phone numbers. And since SQL Server… Read More INSERT INTO auto increment identity for a one-column table
I want to store Genetic variants of patients in a database. Number of patients are around 1000 but for each patient there are more than 100,000 Genetic variants. Can anyone advice me how to design this table. Is it possible to do this in MongoDB ? The data will look something like this. Any help… Read More Is it possible to store 100,000+ columns in a database table?
ColorBreakdown id color amount 0 red 25 0 blue 13 1 red 16 1 blue 17 Color name red blue Given the tables above, how do I separate it into the table below without altering said table? (only by selecting, joining, filtering etc.) id red blue 0 25 13 0 16 17 I am totally… Read More Without altering the original table, how do filter and separate two different items of the same column into two different columns?
I’m currently working on a mobile application. The principle is simple, a user can add a marker on a map. The marker belongs to a category and each category has different fields. Example : A user adds a marker on the map, chooses the category (point of interest) then fills in the necessary information for… Read More MySql – need help modeling database
I am looking to create a table that will only accept certain values in my database and I came across the default values option but I am sure that this won’t be something that would work but just wanted to clarify. As far as I am aware the default option, would allow you to store… Read More Set a Table in Oracle to Only Accept Certain Values for a Column