Crate arrow_odbc

source · [−]
Expand description

Fill Apache Arrow arrays from ODBC data sources.

Usage

use arrow_odbc::{odbc_api::Environment, OdbcReader};

const CONNECTION_STRING: &str = "\
    Driver={ODBC Driver 17 for SQL Server};\
    Server=localhost;\
    UID=SA;\
    PWD=My@Test@Password1;\
";

fn main() -> Result<(), anyhow::Error> {
    // Your application is fine if you spin up only one Environment.
    let odbc_environment = Environment::new()?;
     
    // Connect with database.
    let connection = odbc_environment.connect_with_connection_string(CONNECTION_STRING)?;

    // This SQL statement does not require any arguments.
    let parameters = ();

    // Execute query and create result set
    let cursor = connection
        .execute("SELECT * FROM MyTable", parameters)?
        .expect("SELECT statement must produce a cursor");

    // Each batch shall only consist of maximum 10.000 rows.
    let max_batch_size = 10_000;

    // Read result set as arrow batches. Infer Arrow types automatically using the meta
    // information of `cursor`.
    let arrow_record_batches = OdbcReader::new(cursor, max_batch_size)?;

    for batch in arrow_record_batches {
        // ... process batch ...
    }

    Ok(())
}

Re-exports

pub use arrow;
pub use odbc_api;

Structs

BufferAllocationOptions

Allows setting limits for buffers bound to the ODBC data source. Check this out if you find that you get memory allocation, or zero sized column errors. Used than constructing a reader using crate::OdbcReader::with.

OdbcReader

Arrow ODBC reader. Implements the arrow::record_batch::RecordBatchReader trait so it can be used to fill Arrow arrays from an ODBC data source.

Enums

ColumnFailure
Error

A variation of things which can go wrong then creating an crate::OdbcReader.

Functions

arrow_schema_from

Query the metadata to create an arrow schema. This method is invoked automatically for you by crate::OdbcReader::new. You may want to call this method in situtation ther you want to create an arrow schema without creating the reader yet.