derive_sql/structs/filter/
condition.rs

1use super::*;
2
3pub enum Operator<T> 
4where T: std::fmt::Display
5{
6  IsNull,
7  IsNotNull,
8  Equal(Value<T>),
9  NotEqual(Value<T>),
10  GreaterThan(Value<T>),
11  GreaterEqual(Value<T>),
12  LowerThan(Value<T>),
13  LowerEqual(Value<T>),
14}
15
16/// Describe a single filtering condition using a label and an operator (with the associated operator value if applicable)
17pub struct Condition<T>
18where T: std::fmt::Display
19{
20  table: Option<String>,
21  label: String,
22  operator: Operator<T>,
23}
24
25impl<T> Condition<T>
26where T: std::fmt::Display
27{
28  pub fn from_table_label_operator(table: Option<String>, label: String, operator: Operator<T>) -> Condition<T> {
29    Condition { table, label, operator }
30  }
31
32  pub fn from_label_operator(label: String, operator: Operator<T>) -> Condition<T> {
33    Condition { table: None, label, operator }
34  }
35}
36
37impl<T> traits::FlavoredFilter for Condition<T>
38where T: std::fmt::Display
39{
40  /// Return the `WHERE` clause associated with the condition
41  fn filter<C, R>(&self, conn: &C) -> Result<String>
42  where C: traits::Connection<R>, R: traits::Row,
43  {
44    let flavor = conn.flavor();
45    let label = if let Some(table) = &self.table {
46      format!("{table}.{label}", 
47        table=flavor.table(table)?, 
48        label=flavor.column(self.label.as_str())?)
49    } else {
50      format!("{label}", 
51        label=flavor.column(self.label.as_str())?)
52    };
53    let r = match &self.operator {
54      Operator::IsNull          => format!("{label} IS NULL"),
55      Operator::IsNotNull       => format!("{label} IS NOT NULL"),
56      Operator::Equal(v)        => format!("{label} = {v}"),
57      Operator::NotEqual(v)     => format!("{label} != {v}"),
58      Operator::GreaterThan(v)  => format!("{label} > {v}"),
59      Operator::GreaterEqual(v) => format!("{label} >= {v}"),
60      Operator::LowerThan(v)    => format!("{label} < {v}"),
61      Operator::LowerEqual(v)   => format!("{label} <= {v}"),
62    };
63    Ok(r)
64  }
65}
66
67#[cfg(test)]
68mod tests {
69  use super::*;
70
71  #[cfg(test)]
72  fn it_display_correct_clause_for_u32() -> Result<()> {
73    use traits::FlavoredFilter;
74    let conn = traits::tests::SQLiteFlavoredConnection {};
75    type Row = traits::tests::Row;
76
77    assert!(Field::from("key").eq(1u32).filter::<_, Row>(&conn)?.eq("`key` = 1"));
78    assert!(Field::from("key").ne(1u32).filter::<_, Row>(&conn)?.eq("`key` != 1"));
79    assert!(Field::from("key").gt(2u32).filter::<_, Row>(&conn)?.eq("`key` > 2"));
80    assert!(Field::from("key").ge(2u32).filter::<_, Row>(&conn)?.eq("`key` >= 2"));
81    assert!(Field::from("key").lt(2u32).filter::<_, Row>(&conn)?.eq("`key` < 2"));
82    assert!(Field::from("key").le(2u32).filter::<_, Row>(&conn)?.eq("`key` <= 2"));
83
84    Ok(())
85  }
86
87  #[cfg(test)]
88  fn it_display_correct_clause_for_string() -> Result<()> {
89    use traits::FlavoredFilter;
90    let conn = traits::tests::SQLiteFlavoredConnection {};
91    type Row = traits::tests::Row;
92
93    assert!(Field::from("key_str").eq("val").filter::<_, Row>(&conn)?.eq("`key_str` = 'val'"));
94    assert!(Field::from("key_str").ne("val").filter::<_, Row>(&conn)?.eq("`key_str` != 'val'"));
95    assert!(Field::from("key_str").gt("val").filter::<_, Row>(&conn)?.eq("`key_str` > 'val'"));
96    assert!(Field::from("key_str").ge("val").filter::<_, Row>(&conn)?.eq("`key_str` >= 'val'"));
97    assert!(Field::from("key_str").lt("val").filter::<_, Row>(&conn)?.eq("`key_str` < 'val'"));
98    assert!(Field::from("key_str").le("val").filter::<_, Row>(&conn)?.eq("`key_str` <= 'val'"));
99
100    Ok(())
101  }
102}
derive_sql/structs/filter/condition.rs

derive_sql/structs/filter/
condition.rs
