heyGrant opened a new issue, #3497:
URL: https://github.com/apache/arrow-datafusion/issues/3497
code first as below:
(you can skip and see the bottom codes about how to get a single value, it's
my way, but I don't like it.)
`use std::sync::Arc;
use datafusion::arrow::datatypes::{
DataType,
Field,
Schema};
use datafusion::arrow::record_batch::RecordBatch;
use datafusion::arrow::array::StringBuilder;
use datafusion::arrow::array::StringArray;
#[tokio::main]
async fn main(){
// create an arrow array first:
let mut sbuilder = StringBuilder::new(100);
sbuilder.append_value("a").unwrap();
sbuilder.append_null().unwrap();
sbuilder.append_value("hello").unwrap();
sbuilder.append_value("add").unwrap();
sbuilder.append_value("aaaaaa").unwrap();
let a = sbuilder.finish();
let schema = Arc::new(Schema::new(vec![
Field::new("a", DataType::Utf8, false),
]));
let batch = RecordBatch::try_new(
schema.clone(),
vec![
Arc::new(a),
],
).unwrap();
// print the first column:
let firstcol = batch.column(0);
println!("{:?}", firstcol);
//so many steps to get a single value from this array. is there a simple
way to do that? who can help me?
let da = firstcol.as_any();
let da1 = da.downcast_ref::<StringArray>();
let singlevalue3 = da1.unwrap();
let s = singlevalue3.value(3);
println!("{:?}",s);
}`
so many steps to get a single value from this array. is there a simple way
to do that? who can help me?
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