Add Query builder #1780
Add Query builder #1780
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* Make query_builder.rs in sqlx-core
* Add QueryBuilder::new()
* Add QueryBuilder::push()
* Define questions for documentation
* Get new, push, push_bind working with types
* Handle postgres' numbered bind varaibles
* Add a test for QueryBuilder#build
* Move arguments into Option
* Refactor query builder
* Finish testing QueryBuilder#build
* Remove design doc
* Add a test for pushing strings with push_bind
* Integration test green
* Adjust some tests
* Make query builder generic about placeholder segmenent ('$N' or '?')
sqlx-core/src/arguments.rs
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| @@ -16,6 +16,10 @@ pub trait Arguments<'q>: Send + Sized + Default { | |||
| fn add<T>(&mut self, value: T) | |||
| where | |||
| T: 'q + Send + Encode<'q, Self::Database> + Type<Self::Database>; | |||
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| fn place_holder(&self, _argument_count: u16) -> String { | |||
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Nit: argument_count shouldn't be necessary as the Arguments impl should already know how many arguments have been pushed. Personally, I also think "placeholder" should be one word, not two.
The intermediate String is also a wasted allocation. An alternative signature might look like this:
use std::fmt::{Self, Write};
fn format_placeholder<W: Write>(&self, mut writer: W) -> fmt::Result {
writer.write_str("?")
}and the Postgres implementation would look like this:
fn format_placeholder<W: Write>(&self, mut writer: W) -> fmt::Result {
write!(writer, "${}", self.count)
}QueryBuilder would then simply invoke it like:
// This is highly unlikely to return an error so panicking is fine.
arguments.format_placeholder(&mut self.query).expect("error in format_placeholder")
sqlx-core/src/query_builder.rs
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| } | ||
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| pub fn push(&mut self, sql: impl Display) -> &mut Self { | ||
| self.query.push_str(&format!(" {}", sql)); |
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| self.query.push_str(&format!(" {}", sql)); | |
| // An error here is also highly unlikely but ignoring it is a code smell. | |
| write!(self.query, " {}", sql).expect("error formatting `sql`"); |
It is a bit weird to insert a space automatically, though. What if someone is trying to concatenate an identifier using this method, or is building a string literal where formatting matters? This violates the principle of least surprise.
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Something that is missing though is some documentation. I can add that myself after merging unless you want to take a shot at it. |
If you feel motivated to do it, go ahead. I probably won't get to it until at least Monday otherwise. |
elaborates on the API introduced in #1780
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This doesn't seem to get passed through the compile time checks, is that correct? |
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@OskarPersson the latest commit is on a different feature branch for PR #1790, when this PR was merged it was passing CI. |
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@abonander Does that PR add compile time checks for queries created using this builder? (I'm not able to test that myself at the moment) |
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No, that's more in the purview of #1491 which may end up as a separate crate. |
elaborates on the API introduced in #1780
elaborates on the API introduced in #1780
elaborates on the API introduced in #1780
elaborates on the API introduced in #1780
elaborates on the API introduced in #1780
elaborates on the API introduced in #1780
elaborates on the API introduced in #1780
elaborates on the API introduced in #1780
elaborates on the API introduced in #1780
elaborates on the API introduced in #1780
elaborates on the API introduced in #1780
#291
I'm not sure how close this is to what was wanted.
Would love some feedback!
:)