Method to_string

datafusion/core/src/dataframe/mod.rs:1518–1532

Execute the `DataFrame` and return a string representation of the results. # Example ``` # use datafusion::prelude::*; # use datafusion::error::Result; # use datafusion::execution::SessionStateBuilder; # #[tokio::main] # async fn main() -> Result<()> { let cfg = SessionConfig::new() .set_str("datafusion.format.null", "no-value"); let session_state = SessionStateBuilder::new() .with_config(cfg) .

(self)

    /// # Ok(())
    /// # }
    pub async fn to_string(self) -> Result<String> {
        let options = self.session_state.config().options().format.clone();
        let arrow_options: arrow::util::display::FormatOptions = (&options).try_into()?;

        let registry = self.session_state.extension_type_registry();
        let formatter_factory = DFArrayFormatterFactory::new(Arc::clone(registry));
        let arrow_options =
            arrow_options.with_formatter_factory(Some(&formatter_factory));

        let results = self.collect().await?;
        Ok(
            pretty::pretty_format_batches_with_options(&results, &arrow_options)?
                .to_string(),
        )
    }

    /// Execute the `DataFrame` and print only the first `num` rows of the
    /// result to the console.