edgedb_query/queries/
conflict.rs

1use edgedb_protocol::value::Value;
2use crate::{EdgeQl, ToEdgeQl, ToEdgeQuery, ToEdgeValue};
3
4
5const UNLESS_CONFLICT: &str = " unless conflict ";
6const ON: &str = "on ";
7const OPEN_PARENTHESIS: &str = "( ";
8const CLOSE_PARENTHESIS: &str = " ) ";
9const COMMA: &str = ", ";
10const ELSE: &str = "else ( ";
11
12/// Conflict trait represents an 'unless conflict' statement in an edgeDB query
13pub trait Conflict<T: ToEdgeQuery + Clone> {
14    fn else_query(&self) -> Option<T>;
15}
16
17/// InsertConflict struct
18#[derive(Debug, Clone)]
19pub struct UnlessConflictElse<T: ToEdgeQuery> {
20    pub else_query: T
21}
22
23impl<T: ToEdgeQuery + Clone> Conflict<T> for UnlessConflictElse<T> {
24    fn else_query(&self) -> Option<T> {
25        Some(self.else_query.clone())
26    }
27}
28
29
30/// DefaultInsertConflict struct
31#[derive(Debug, Clone)]
32pub struct UnlessConflict;
33
34#[derive(Clone)]
35pub struct EmptyQuery;
36
37impl ToEdgeQl for EmptyQuery {
38    fn to_edgeql(&self) -> EdgeQl {
39        EdgeQl::default()
40    }
41}
42
43impl ToEdgeValue for EmptyQuery {
44    fn to_edge_value(&self) -> Value {
45        Value::Nothing
46    }
47}
48
49impl ToEdgeQuery for EmptyQuery{}
50
51impl Conflict<EmptyQuery> for UnlessConflict {
52    fn else_query(&self) -> Option<EmptyQuery> {
53        None
54    }
55}
56
57
58/// parse a conflict into a string statement
59///
60/// ## Examples
61///
62/// ```
63///use edgedb_protocol::value::Value;
64///use edgedb_query::queries::conflict::{UnlessConflictElse, Conflict, parse_conflict};
65///use edgedb_query::{ToEdgeQl, ToEdgeQuery, ToEdgeValue};
66///
67///#[derive(Clone)]
68///pub struct FindUser {}
69///
70///impl ToEdgeQl for FindUser {
71///   fn to_edgeql(&self) -> String {
72///       format!("select users")
73///   }
74///}
75///
76///impl ToEdgeValue for FindUser {
77///   fn to_edge_value(&self) -> Value {
78///       Value::Nothing
79///   }
80///}
81///
82///impl ToEdgeQuery for FindUser  {}
83///
84///fn main() {
85///   let insert_conflict = UnlessConflictElse {
86///       else_query: Some(FindUser{}),
87///   };
88///
89///   let stmt = parse_conflict(&insert_conflict, vec!["name", "age"]);
90///
91///    assert_eq!(stmt, " unless conflict on ( .name, .age ) else ( select users )");
92/// }
93/// ```
94pub fn parse_conflict<T: ToEdgeQuery + Clone, R: Conflict<T>>(conflict: &R, on_fields: Vec<&str>) -> String {
95    let mut stmt = UNLESS_CONFLICT.to_owned();
96
97    if !on_fields.is_empty() {
98
99        stmt.push_str(ON);
100
101        if on_fields.len() > 1 {
102            stmt.push_str(OPEN_PARENTHESIS);
103        }
104
105        stmt.push_str(on_fields
106            .iter()
107            .map(|s| format!(".{s}"))
108            .collect::<Vec<String>>()
109            .join(COMMA).as_str()
110        );
111
112        if on_fields.len() > 1 {
113            stmt.push_str(CLOSE_PARENTHESIS);
114        } else {
115            stmt.push(' ');
116        }
117    }
118
119    if let Some(else_query)= conflict.else_query() {
120        stmt.push_str(ELSE);
121        stmt.push_str(else_query.to_edgeql().to_string().as_str());
122        stmt.push_str(CLOSE_PARENTHESIS);
123    }
124
125    stmt
126}
127
edgedb_query/queries/conflict.rs

edgedb_query/queries/
conflict.rs
