generated from alecodes/base-template
95 lines
2.9 KiB
Go
95 lines
2.9 KiB
Go
package synchronizator
|
|
|
|
type StandardNode interface{}
|
|
|
|
// A node in the database.
|
|
// It adds some helper methods to easily manage the node.
|
|
type Node struct {
|
|
_conn *DB // Underlaying connection to the database.
|
|
_class string // The class of the node, should not be modified to avoid inconsistencies.
|
|
_relationships []*Relationship // Relationships of the node
|
|
Id int64 // The id of the node
|
|
name string // The name of the node
|
|
metadata []byte // Arbitrary data. This is stored as a jsonb in the database
|
|
}
|
|
|
|
// Creates a new relation of type StandardRelationship to the node with the
|
|
// provided id. An error is returned if the relation already exists.
|
|
//
|
|
// This method is a wrapper around the AddRelation method of the connection.
|
|
func (node *Node) AddRelation(relation StandardRelationship, to int64) (*Relationship, error) {
|
|
return node._conn.AddRelation(node.Id, relation, to)
|
|
}
|
|
|
|
// Update a relation with the node of the provided id.
|
|
//
|
|
// This method is a wrapper around the UpdateRelation method of the connection.
|
|
func (node *Node) UpdateRelation(metadata any, to int64) error {
|
|
return node._conn.UpdateRelation(node.Id, metadata, to)
|
|
}
|
|
|
|
// Delete a relation with the node of the provided id.
|
|
//
|
|
// This method is a wrapper around the DeleteRelation method of the connection.
|
|
func (node *Node) DeleteRelation(to int64) error {
|
|
return node._conn.DeleteRelation(node.Id, to)
|
|
}
|
|
|
|
// Fetch all the outgoing relations for this node. This method will return a
|
|
// slice of relationships pointers and also store them in the node for further
|
|
// use.
|
|
func (node *Node) GetOutRelations() ([]*Relationship, error) {
|
|
sql := `
|
|
WITH RECURSIVE NodeRelationships AS (
|
|
SELECT
|
|
*,
|
|
relationships._class AS relationship_class,
|
|
relationships.metadata AS relationship_metadata
|
|
FROM
|
|
nodes as src
|
|
JOIN relationships ON src.id = relationships.node_from
|
|
WHERE src.id = $1
|
|
)
|
|
SELECT
|
|
NodeRelationships.id as src_node,
|
|
NodeRelationships.relationship_class,
|
|
NodeRelationships.relationship_metadata,
|
|
dst.id as dst_id
|
|
FROM
|
|
NodeRelationships
|
|
JOIN nodes as dst ON dst.id = NodeRelationships.node_to
|
|
`
|
|
|
|
rows, err := node._conn.Query(sql, node.Id)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
defer rows.Close()
|
|
|
|
node._relationships = make([]*Relationship, 0)
|
|
for rows.Next() {
|
|
relationship := &Relationship{
|
|
_conn: node._conn,
|
|
}
|
|
|
|
if err := rows.Scan(&relationship.From, &relationship._class, &relationship.Metadata, &relationship.To); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
node._relationships = append(node._relationships, relationship)
|
|
}
|
|
|
|
return node._relationships, nil
|
|
}
|
|
|
|
// Deletes this node from the database.
|
|
// This method is a wrapper around the DeleteNode method of the connection.
|
|
func (node *Node) Delete() error {
|
|
return node._conn.DeleteNode(node.Id)
|
|
}
|
|
|
|
// Returns the class of the node
|
|
func (relationship *Relationship) GetClass() string {
|
|
return relationship._class
|
|
}
|