radiant mantle
I could not find a way to pass &str from local String variable to function https://github.com/gintsgints/grpc-bdt-server/blob/master/src/main.rs
let constraint = format!("{} {} ${}", filter.column.to_string().clone(), filter.operator.to_string().clone(), i + 1);
select = select.where_clause(&constraint).clone();
ember widget
that builder interface requires you to provide strings that are borrowed from a source that outlives the builder
that means that you need 2 loops, one to format the strings (which must be put in a Vec or something), and another one to call the builder
all of the .to_string().clone() is unnecessary and irrelevant — the problem is that constraint is a local String inside the loop, but where_clause needs to be given a borrow of something that outlives the loop
radiant mantle
Ok. I try with two loops now.
Hmm in second loop I get the same
let mut constraints: Vec<String> = vec![];
for (i, filter) in req.filters.iter().enumerate() {
let constraint = format!("{} {} ${}", filter.column, filter.operator, i + 1);
constraints.push(constraint);
};
for constraint in constraints {
select = select.where_clause(&constraint);
}
seems solved by combining it myself in one string instead of second loop.
ember widget
you would need to fill constraints before you create the select builder
radiant mantle
Does not help. Or I do somthing wrong :
let query_str = {
let select_str = req.columns.iter().map(|x| x.name.to_string()).collect::<Vec<_>>().join(",");
let mut constraints: Vec<String> = vec![];
for (i, filter) in req.filters.iter().enumerate() {
let constraint = format!("{} {} ${}", filter.column, filter.operator, i + 1);
constraints.push(constraint);
};
let mut select = sql_query_builder::Select::new()
.select(&select_str)
.from(req.table.as_str());
for constraint in constraints {
select = select.where_clause(&constraint);
}
select.as_string()
};
still second loop gives error.
As I see it complains on using constraint, because it is destroyed in loop body.
ember widget
oh. you need for constraint in &constraints to do that