How to store dynamic data in database?

How to store data with dynamic number of attributes in a database

1. Having one single field named “attributes” in the object’s table and store the data serialized or json’ed in there.
2. Storing the data in two tables (objects, attributes) and using a third to save the relations, making it a true n:m relation.

How do I store a list of strings in a database?

14 Answers. No, there is no “better” way to store a sequence of items in a single column. Relational databases are designed specifically to store one value per row/column combination. In order to store more than one value, you must serialize your list into a single value for storage, then deserialize it upon retrieval.

How do you store values in a database?

A row, also called a record, is each individual entry that exists in a table. Each column represents an attribute of the car, and each row stores all of the attributes of that specific car. You can create any table you want with SQL, to keep multiple types of data (text, numbers, dates, etc.).

What is EAV database?

Entity–attribute–value model (EAV) is a data model to encode, in a space-efficient manner, entities where the number of attributes (properties, parameters) that can be used to describe them is potentially vast, but the number that will actually apply to a given entity is relatively modest.

Can we store array in database?

You can store the array using serialize / unserialize . With that solution they cannot easily be used from other programming languages, so you may consider using json_encode / json_decode instead (which gives you a widely supported format).

Where do you store databases?

Database tables and indexes may be stored on disk in one of a number of forms, including ordered/unordered flat files, ISAM, heap files, hash buckets, or B+ trees. Each form has its own particular advantages and disadvantages. The most commonly used forms are B-trees and ISAM.

How is data physically stored in a database?

The logical units of database space allocation are data blocks, extents, segments, and tablespaces. At a physical level, the data is stored in data files on disk (see Chapter 11, “Physical Storage Structures”). The data in the data files is stored in operating system blocks.

Should I use EAV model?

EAV model is excellent for rapidly evolving applications because it protects us against consequences of constant change. We can simply record new data of any structure without the need to modify the database schema.

Is EAV an Antipattern?

To get your interest into database normalization, we see what could happen when you neglect to normalize properly, with a selection of three classic anti-patterns: the infamous EAV, using multiple values in a single column, and how using UUIDs might be an anti-pattern too.

How do I pass a list of strings in SQL query?

“How to pass list as parameter in SQL query” Code Answer

1. private static String sqlFormatedList(List list){
2. StringBuilder sb = new StringBuilder();
3. sb. append(“(‘”);
4. for (String i : list){
5. sb. append(i+”‘,'”);
6. }
7. sb. deleteCharAt(sb. length() -1);
8. sb. deleteCharAt(sb. lastIndexOf(“,”));