avro_sql.rs

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// to you under the Apache License, Version 2.0 (the
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//
//   http://www.apache.org/licenses/LICENSE-2.0
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use datafusion::arrow::util::pretty;

use datafusion::error::Result;
use datafusion::prelude::*;

/// This example demonstrates executing a simple query against an Arrow data source (Avro) and
/// fetching results
#[tokio::main]
async fn main() -> Result<()> {
    // create local execution context
    let ctx = SessionContext::new();

    let testdata = datafusion::test_util::arrow_test_data();

    // register avro file with the execution context
    let avro_file = &format!("{testdata}/avro/alltypes_plain.avro");
    ctx.register_avro("alltypes_plain", avro_file, AvroReadOptions::default())
        .await?;

    // execute the query
    let df = ctx
        .sql(
            "SELECT int_col, double_col, CAST(date_string_col as VARCHAR) \
        FROM alltypes_plain \
        WHERE id > 1 AND tinyint_col < double_col",
        )
        .await?;
    let results = df.collect().await?;

    // print the results
    pretty::print_batches(&results)?;

    Ok(())
}