1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123

use serde_json::Value;
use std::borrow::Cow;

#[derive(Debug, Serialize)]
pub struct Query<'a> {
    query: &'a str,
    parameters: Cow<'a, [Param<'a>]>,
}

#[derive(Debug, Serialize, Clone)]
pub struct Param<'a> {
    name: &'a str,
    value: Cow<'a, Value>,
}

#[derive(Debug, Serialize, Clone)]
pub struct ParamDef<'a> {
    name: &'a str,
}

impl<'a> Param<'a> {
    pub fn new<T: Into<Value>>(name: &'a str, value: T) -> Self {
        Self {
            name,
            value: Cow::Owned(value.into()),
        }
    }

    pub fn new_ref(name: &'a str, value: &'a Value) -> Self {
        Self {
            name,
            value: Cow::Borrowed(value),
        }
    }

    pub fn name(&self) -> &'a str {
        self.name
    }

    pub fn value(&self) -> &Value {
        self.value.as_ref()
    }
}

impl<'a> ParamDef<'a> {
    pub fn new(name: &'a str) -> Self {
        Self { name }
    }

    pub fn value<T: Into<Value>>(&self, value: T) -> Param<'a> {
        Param {
            name: self.name,
            value: Cow::Owned(value.into()),
        }
    }

    pub fn value_ref(&self, value: &'a Value) -> Param<'a> {
        Param {
            name: self.name,
            value: Cow::Borrowed(value),
        }
    }
}

impl<'a> Query<'a> {
    pub fn new(query: &'a str) -> Self {
        Self::with_params(query, vec![])
    }

    pub fn with_params<T: Into<Cow<'a, [Param<'a>]>>>(query: &'a str, params: T) -> Self {
        Self {
            query,
            parameters: params.into(),
        }
    }

    pub fn query(&self) -> &'a str {
        self.query
    }

    pub fn params(&self) -> &[Param<'a>] {
        &self.parameters
    }
}

impl<'a> From<&'a str> for Query<'a> {
    fn from(query: &'a str) -> Query<'a> {
        Query::new(query)
    }
}

impl<'a> AsRef<Query<'a>> for Query<'a> {
    fn as_ref(&self) -> &Query<'a> {
        &self
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use serde_json;

    #[test]
    fn tst_query() {
        let p1 = ParamDef::new("p1");
        let v3 = Value::from(vec![1, 2, 3]);
        let query = Query::with_params(
            "SELECT * FROM t",
            vec![
                p1.value("string"),
                Param::new("p2", 100u64),
                Param::new_ref("p3", &v3),
            ],
        );

        let ser = serde_json::to_string(&query).unwrap();

        assert_eq!(
            ser,
            r#"{"query":"SELECT * FROM t","parameters":[{"name":"p1","value":"string"},{"name":"p2","value":100},{"name":"p3","value":[1,2,3]}]}"#
        );
    }
}