entity-attribute-value | 易学教程

EAV over SQL Server

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问题 I'm interested in playing around with the EAV model over an SQL Server Database. Is anybody able to point me to an article or framework for an existing model/schema (I'm not intrested in Saas for this)? 回答1: Best Practices for Semantic Data Modeling for Perfor... EAV is notoriusly problematic as it leads to severe deployment performance and scalability problems. The Whitepaper in the link, released by the SQL Server Customer Advisory Team tries to offer some guidance to deploy a succesful EAV

Designing an EAV database correctly for historical data

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Intro I have been reading about EAV database and most of the short comings seem to be related to really, really, bad EAV designs or difficulty generating reports from the data . Usually when you see people complaining about EAV they are using less than three tables to try to replicate the functionally of separate tables + columns in a RDBMS. Sometimes that means storing everything from decimals to strings in a single TEXT value column. EAV also messes with the safe-guards over data integrity which can be very bad if you are not careful. However, EAV does provide an easy way to track historical

Alternatives to Entity-Attribute-Value (EAV)?

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问题 Our database is designed based on EAV (Entity-Attribute-Value) model. Those who have worked with EAV models know all the crap that comes with for the purpose of flexibility. I asked my client about the reasons why using EAV model (flexibility), and their response was: Their entities change over time. So, today they may have a table with a few attributes, but in a month time, a few new attributes may be added, or an existing attribute may be renamed. They need to produce reports to get back to

Best beginner resources for understanding the EAV database model? [closed]

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问题 Closed. This question is off-topic. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 4 years ago . I\'m doing some custom work with Magento, which has a database design based upon the EAV model, and I need some good resources/tutorials that explain the EAV database model. Please don\'t provide Wikipedia as a resource... I\'m looking for something that teaches EAV in a friendly way for beginners. 回答1: Here you

Database EAV Pros/Cons and Alternatives

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问题 I have been looking for a database solution to allow user defined fields and values (allowing an unlimited number). At first glance, EAV seemed like the right fit, but after some reading I am not sure anymore. What are the pros and cons of EAV? Is there an alternative database method to allow user defined attributes/fields and values? 回答1: This is not to be considered an exhaustive answer, but just a few points on the topic. Since the question is also tagged with the [sql] tag, let me say

ALTER TABLE in Magento setup script without using SQL

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问题 Jonathon Day says \"updates SHOULD NOT be in the form of SQL commands\". I haven\'t come across any DDL or DML statments that cannot be executed via Magento\'s config structures. (In the question How can I migrate configuration changes from development to production environment?) I would like to know how best to add/modify/remove a column or index to/from a table in this manner, but without relying on SQL? Is it even possible? Furthermore, what other actions can only be done in SQL? 回答1: You

Should I use EAV model?

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问题 I\'m am designing my database/domain for an eCommerce application and I\'m having a hard time figuring out how to store products. The website will sell a wide range of products, pens, thongs, tattoos, umbrellas, everything. Each of these product will share a few common attributes, height, width, length, weight, etc but some products have special data. For example, pens have different ink colors and tips/lids and brochures can have different types of folds. So far I have thought up some 20+

Magento - Retrieve products with a specific attribute value

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问题 In my block code I am trying to programmatically retrieve a list of products that have a attribute with a specific value. Alternately if that is not possible how would one retrieve all products then filter them to just list the products with a specific attribute? How would I perform a search using standard boolean filters AND or OR to match a subset of my products? 回答1: Almost all Magento Models have a corresponding Collection object that can be used to fetch multiple instances of a Model. To

Designing an EAV database correctly for historical data

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问题 Intro I have been reading about EAV database and most of the short comings seem to be related to really, really, bad EAV designs or difficulty generating reports from the data. Usually when you see people complaining about EAV they are using less than three tables to try to replicate the functionally of separate tables + columns in a RDBMS. Sometimes that means storing everything from decimals to strings in a single TEXT value column. EAV also messes with the safe-guards over data integrity

How to pivot a MySQL entity-attribute-value schema

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问题 I need to design tables which stores all the metadata of files (i.e., file name, author, title, date created), and custom metadata (which has been added to files by users, e.g. CustUseBy, CustSendBy). The number of custom metadata fields cannot be set beforehand. Indeed, the only way of determining what and how many custom tags have been added on files is to examine what exists in the tables. To store this, I have created a base table (having all common metadata of files), an Attributes table