Atlas中，Rdbms元模型的理解

组合关系&＃xff1a;table可以有多个外键&＃xff0c;外键只能属于某个table

{"name": "rdbms_table_foreign_key","serviceType": "rdbms","typeVersion": "1.2","relationshipCategory": "COMPOSITION","relationshipLabel": "__rdbms_table.foreign_keys","endDef1": {"type": "rdbms_table","name": "foreign_keys","isContainer": true,"cardinality": "SET","isLegacyAttribute": true},"endDef2": {"type": "rdbms_foreign_key","name": "table","isContainer": false,"cardinality": "SINGLE","isLegacyAttribute": true},"propagateTags": "NONE"
}


关联关系&＃xff1a;外键实体引用哪个表的外键&＃xff1b;我这个表的外键&＃xff0c;被哪个外键实体引用。

{"name": "rdbms_foreign_key_table_references","serviceType": "rdbms","typeVersion": "1.2","relationshipCategory": "ASSOCIATION","relationshipLabel": "__rdbms_foreign_key.references_table","endDef1": {"type": "rdbms_foreign_key","name": "references_table","isContainer": false,"cardinality": "SINGLE","isLegacyAttribute": true},"endDef2": {"type": "rdbms_table","name": "foreign_key_references","isContainer": false,"cardinality": "SET"},"propagateTags": "NONE"
}


关联关系&＃xff1a;外键由几个字段构成&＃xff0c;字段被哪些外键引用

{"name": "rdbms_foreign_key_column_references","serviceType": "rdbms","typeVersion": "1.2","relationshipCategory": "ASSOCIATION","relationshipLabel": "__rdbms_foreign_key.references_columns","endDef1": {"type": "rdbms_foreign_key","name": "references_columns","isContainer": false,"cardinality": "SET","isLegacyAttribute": true},"endDef2": {"type": "rdbms_column","name": "foreign_key_references","isContainer": false,"cardinality": "SET"},"propagateTags": "NONE"
}


详情

tableA&＃xff1a;id&＃xff0c;[classId,className]&＃xff08;外键&＃xff09;tableB&＃xff1a;classId&＃xff0c;className外键实体:
references_table&＃xff1a;tableB
table&＃xff1a;tableA
references_columns&＃xff1a;classId,className例子说明&＃xff1a;tableA&＃xff0c;有一个外键&＃xff0c;由[classId,className]构成tableB&＃xff0c;有两个字段&＃xff0c;是tableA的外键外键实体&＃xff0c;属于tableA的&＃xff0c;被tableB引用&＃xff0c;这个外键引用两个字段[classId,className]