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]}]}"#
);
}
}