1. 节点模型
```sql
CREATE TABLE nodes (
id TEXT PRIMARY KEY,
type TEXT NOT NULL,
label TEXT NOT NULL,
x REAL NOT NULL,
y REAL NOT NULL,
created_at TEXT NOT NULL,
updated_at TEXT NOT NULL
)
```
2. 节点属性模型
```sql
CREATE TABLE node_properties (
node_id TEXT NOT NULL,
key TEXT NOT NULL,
value TEXT,
FOREIGN KEY (node_id) REFERENCES nodes(id) ON DELETE CASCADE,
PRIMARY KEY (node_id, key)
)
```
3. 关系模型
```sql
CREATE TABLE relationships (
id TEXT PRIMARY KEY,
source_id TEXT NOT NULL,
target_id TEXT NOT NULL,
type TEXT NOT NULL,
created_at TEXT NOT NULL,
FOREIGN KEY (source_id) REFERENCES nodes(id) ON DELETE CASCADE,
FOREIGN KEY (target_id) REFERENCES nodes(id) ON DELETE CASCADE
)
```
4. 关系属性模型
```sql
CREATE TABLE relationship_properties (
relationship_id TEXT NOT NULL,
key TEXT NOT NULL,
value TEXT,
FOREIGN KEY (relationship_id) REFERENCES relationships(id) ON DELETE CASCADE,
PRIMARY KEY (relationship_id, key)
)
```