java eav_动态自定义字段属性–Magento的EAV模型 | 学步园
EAV ： Entity - Attribute - Value 的縮寫，是數(shù)據(jù)庫模型的一種，使用eav建模的好處是可以動態(tài)為數(shù)據(jù)模型增加或移除屬性。
1. 問題提出:
假設(shè)需要定義一個實體Customer的信息，通常我們只要定義一個表為customer，并定義相應(yīng)的屬性即可。倘若某天需要為customer增加一個新的屬性如“畢業(yè)學(xué)校”，那么就需要更改表的結(jié)構(gòu)。
如果使用EAV模型則不必改變表結(jié)構(gòu)。
2. Magento的EAV模型定義:
在Magento中，EAV模型相關(guān)的表定義有：
Java代碼
eav_attribute
eav_attribute_group
eav_attribute_option
eav_attribute_option_value
eav_attribute_set
eav_entity
eav_entity_attribute
eav_entity_datetime
eav_entity_decimal
eav_entity_int
eav_entity_store
eav_entity_text
eav_entity_type
eav_entity_varchar
eav_attribute
eav_attribute_group
eav_attribute_option
eav_attribute_option_value
eav_attribute_set
eav_entity
eav_entity_attribute
eav_entity_datetime
eav_entity_decimal
eav_entity_int
eav_entity_store
eav_entity_text
eav_entity_type
eav_entity_varchar
現(xiàn)在讓我來觀察最重要的三張表
eav_entity_type，eav_entity_attribute，eav_attribute
1) eav_entity_type表用來定義實體的基本信息。
Sql代碼
mysql>select*fromeav_entity_typewhereentity_type_id=1;
+----------------+------------------+-------------------+-----------------+-----------------+
|?entity_type_id?|?entity_type_code?|?entity_model??????|?attribute_model?|?entity_table????|?+----------------+------------------+-------------------+-----------------+-----------------+
|??????????????1?|?customer?????????|?customer/customer?|?????????????????|?customer/entity?|
+----------------+------------------+-------------------+-----------------+-----------------+
mysql> select * from eav_entity_type where entity_type_id=1;
+----------------+------------------+-------------------+-----------------+-----------------+
| entity_type_id | entity_type_code | entity_model | attribute_model | entity_table | +----------------+------------------+-------------------+-----------------+-----------------+
| 1 | customer | customer/customer | | customer/entity |
+----------------+------------------+-------------------+-----------------+-----------------+
2). eav_entity_attribute表用來定義實體customer模型包含哪些屬性
Sql代碼
mysql>select*fromeav_entity_attributewhereentity_type_id='1';
+---------------------+----------------+------------------+--------------------+--------------+
|?entity_attribute_id?|?entity_type_id?|?attribute_set_id?|?attribute_group_id?|?attribute_id?|
+---------------------+----------------+------------------+--------------------+--------------+
|???????????????????1?|??????????????1?|????????????????1?|??????????????????1?|????????????1?|
|???????????????????2?|??????????????1?|????????????????1?|??????????????????1?|????????????2?|
|???????????????????3?|??????????????1?|????????????????1?|??????????????????1?|????????????3?|
|???????????????????4?|??????????????1?|????????????????1?|??????????????????1?|????????????4?|
|???????????????????5?|??????????????1?|????????????????1?|??????????????????1?|????????????5?|
|???????????????????6?|??????????????1?|????????????????1?|??????????????????1?|????????????6?|
|???????????????????7?|??????????????1?|????????????????1?|??????????????????1?|????????????7?|
|???????????????????8?|??????????????1?|????????????????1?|??????????????????1?|????????????8?|
|???????????????????9?|??????????????1?|????????????????1?|??????????????????1?|????????????9?|
|??????????????????10?|??????????????1?|????????????????1?|??????????????????1?|???????????10?|
|??????????????????11?|??????????????1?|????????????????1?|??????????????????1?|???????????11?|
|??????????????????12?|??????????????1?|????????????????1?|??????????????????1?|???????????12?|
|??????????????????13?|??????????????1?|????????????????1?|??????????????????1?|???????????13?|
|??????????????????14?|??????????????1?|????????????????1?|??????????????????1?|???????????14?|
|??????????????????15?|??????????????1?|????????????????1?|??????????????????1?|???????????15?|
|??????????????????16?|??????????????1?|????????????????1?|??????????????????1?|???????????16?|
+---------------------+----------------+------------------+--------------------+--------------+
mysql> select * from eav_entity_attribute where entity_type_id='1';
+---------------------+----------------+------------------+--------------------+--------------+
| entity_attribute_id | entity_type_id | attribute_set_id | attribute_group_id | attribute_id |
+---------------------+----------------+------------------+--------------------+--------------+
| 1 | 1 | 1 | 1 | 1 |
| 2 | 1 | 1 | 1 | 2 |
| 3 | 1 | 1 | 1 | 3 |
| 4 | 1 | 1 | 1 | 4 |
| 5 | 1 | 1 | 1 | 5 |
| 6 | 1 | 1 | 1 | 6 |
| 7 | 1 | 1 | 1 | 7 |
| 8 | 1 | 1 | 1 | 8 |
| 9 | 1 | 1 | 1 | 9 |
| 10 | 1 | 1 | 1 | 10 |
| 11 | 1 | 1 | 1 | 11 |
| 12 | 1 | 1 | 1 | 12 |
| 13 | 1 | 1 | 1 | 13 |
| 14 | 1 | 1 | 1 | 14 |
| 15 | 1 | 1 | 1 | 15 |
| 16 | 1 | 1 | 1 | 16 |
+---------------------+----------------+------------------+--------------------+--------------+
3), 由上表推出customer實體包含16個屬性，下面的語句查看每個屬性的具體定義
Sql代碼
mysql>select*fromeav_attributewhereattribute_id<=16andattribute_id>=1?;
+--------------+----------------+------------------+--------------+
|?attribute_id?|?entity_type_id?|?attribute_code???|?backend_type?|
+--------------+----------------+------------------+--------------+
|????????????1?|??????????????1?|?website_id???????|?static|
|????????????2?|??????????????1?|?store_id?????????|?static|
|????????????3?|??????????????1?|?created_in???????|?varchar|
|????????????4?|??????????????1?|?prefix???????????|?varchar|
|????????????5?|??????????????1?|?firstname????????|?varchar|
|????????????6?|??????????????1?|?middlename???????|?varchar|
|????????????7?|??????????????1?|?lastname?????????|?varchar|
|????????????8?|??????????????1?|?suffix???????????|?varchar|
|????????????9?|??????????????1?|?email????????????|?static|
|???????????10?|??????????????1?|?group_id?????????|?static|
|???????????11?|??????????????1?|?dob??????????????|?datetime?????|
|???????????12?|??????????????1?|?password_hash????|?varchar|
|???????????13?|??????????????1?|?default_billing??|?int|
|???????????14?|??????????????1?|?default_shipping?|?int|
|???????????15?|??????????????1?|?taxvat???????????|?varchar|
|???????????16?|??????????????1?|?confirmation?????|?varchar|
+--------------+----------------+------------------+--------------+
mysql> select * from eav_attribute where attribute_id<=16 and attribute_id>=1 ;
+--------------+----------------+------------------+--------------+
| attribute_id | entity_type_id | attribute_code | backend_type |
+--------------+----------------+------------------+--------------+
| 1 | 1 | website_id | static |
| 2 | 1 | store_id | static |
| 3 | 1 | created_in | varchar |
| 4 | 1 | prefix | varchar |
| 5 | 1 | firstname | varchar |
| 6 | 1 | middlename | varchar |
| 7 | 1 | lastname | varchar |
| 8 | 1 | suffix | varchar |
| 9 | 1 | email | static |
| 10 | 1 | group_id | static |
| 11 | 1 | dob | datetime |
| 12 | 1 | password_hash | varchar |
| 13 | 1 | default_billing | int |
| 14 | 1 | default_shipping | int |
| 15 | 1 | taxvat | varchar |
| 16 | 1 | confirmation | varchar |
+--------------+----------------+------------------+--------------+
所以，使用上述的模型，一旦有CUSTOMER屬性定義的添加和刪除，只需要增加或刪除 eav_entity_attribute的記錄即可
3. 使用EAV模型
現(xiàn)在，在Magento系統(tǒng)注冊一個新的用戶，看看實例數(shù)據(jù)如何存放在數(shù)據(jù)庫
Sql代碼
mysql>select*fromcustomer_entity????????????;
+-----------+----------------+------------------+------------+--------------------+
|?entity_id?|?entity_type_id?|?attribute_set_id?|?website_id?|?email??????????????|
+-----------+----------------+------------------+------------+--------------------+
|?????????1?|??????????????1?|????????????????0?|??????????1?|?koda.guo@gmail.com?|
+-----------+----------------+------------------+------------+--------------------+
mysql>?select*fromcustomer_entity_varchar????;
+----------+----------------+--------------+-----------+-------------------------------------+
|?value_id?|?entity_type_id?|?attribute_id?|?entity_id?|?value???????????????????????????????|
+----------+----------------+--------------+-----------+-------------------------------------+
|????????1?|??????????????1?|????????????5?|?????????1?|?Koda????????????????????????????????|
|????????2?|??????????????1?|????????????7?|?????????1?|?Guo?????????????????????????????????|
|????????4?|??????????????1?|????????????3?|?????????1?|?DefaultStoreView|
|????????5?|??????????????1?|???????????12?|?????????1?|?2256e441b74ab3454a41c821f5de1e9d:9s?|
+----------+----------------+--------------+-----------+-------------------------------------+
mysql> select * from customer_entity ;
+-----------+----------------+------------------+------------+--------------------+
| entity_id | entity_type_id | attribute_set_id | website_id | email |
+-----------+----------------+------------------+------------+--------------------+
| 1 | 1 | 0 | 1 | koda.guo@gmail.com |
+-----------+----------------+------------------+------------+--------------------+
mysql> select * from customer_entity_varchar ;
+----------+----------------+--------------+-----------+-------------------------------------+
| value_id | entity_type_id | attribute_id | entity_id | value |
+----------+----------------+--------------+-----------+-------------------------------------+
| 1 | 1 | 5 | 1 | Koda |
| 2 | 1 | 7 | 1 | Guo |
| 4 | 1 | 3 | 1 | Default Store View |
| 5 | 1 | 12 | 1 | 2256e441b74ab3454a41c821f5de1e9d:9s |
+----------+----------------+--------------+-----------+-------------------------------------+
從上表看到customer_entity 和customer_entity_varchar用來存放相應(yīng)屬性的實際輸入值。如：
Koda, Guo分別屬性編號5,7即firstname和lastname實際值
和customer實體定義相對應(yīng)的實例存放的相關(guān)表包括：
Java代碼
customer_entity
customer_entity_datetime
customer_entity_decimal
customer_entity_int
customer_entity_text
customer_entity_varchar
customer_entity
customer_entity_datetime
customer_entity_decimal
customer_entity_int
customer_entity_text
customer_entity_varchar
總結(jié)
了解Magento的EAV模型結(jié)構(gòu)是擴展Magento必須的知識。 其意義在于，我們常常需要擴展Magento某些實體的屬性，或者創(chuàng)建自定義的eav模型實例。希望本文對你有所啟示。
總結(jié)
以上是生活随笔為你收集整理的java eav_动态自定义字段属性–Magento的EAV模型 | 学步园的全部內(nèi)容，希望文章能夠幫你解決所遇到的問題。
- 上一篇： 卷积神经网络的整体结构、卷积层、池化、p
- 下一篇： hive不在同一台机 hue_环境篇：呕