Joseph-Rance commented on code in PR #4773:
URL: https://github.com/apache/arrow-rs/pull/4773#discussion_r1347137401
##########
parquet_derive/README.md:
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@@ -77,16 +77,55 @@ writer.close_row_group(row_group).unwrap();
writer.close().unwrap();
```
+Example usage of deriving a `RecordReader` for your struct:
+
+```rust
+use parquet::file::{serialized_reader::SerializedFileReader,
reader::FileReader};
+use parquet_derive::ParquetRecordReader;
+
+#[derive(ParquetRecordReader)]
+struct ACompleteRecord {
+ pub a_bool: bool,
+ pub a_string: String,
+ pub i16: i16,
+ pub i32: i32,
+ pub u64: u64,
+ pub isize: isize,
+ pub float: f32,
+ pub double: f64,
+ pub now: chrono::NaiveDateTime,
+ pub byte_vec: Vec<u8>,
+}
+
+// Initialize your parquet file
+let reader = SerializedFileReader::new(file).unwrap();
+let mut row_group = reader.get_row_group(0).unwrap();
+
+// create your records to read into
+let mut chunks = vec![ACompleteRecord{ ... }];
Review Comment:
I spent some time trying to get this to work, but it requires quite a lot of
implementation (or I am doing something wrong) because we need to somehow
generate identifiers for each slice and then feed them through to be used later
when constructing the structs.
It is definitely possible to do this, but I think I have found a slightly
easier way to do this. What do you think of the changes I just pushed? All
fields we currently support implement default so I think this should have
identical behaviour from the user's point of view.
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