`odbc-iter` is a Rust high level database access library based on `odbc` crate that uses native ODBC drivers to access a variety of databases.
With this library you can:
* connect to any database supporting ODBC standard (e.g. via `unixodbc` library and ODBC database driver),
* run one-off, prepared or parametrized queries,
* iterate result set via standard `Iterator` interface,
* automatically convert rows into:
* tuples of Rust standard types,
* custom type implementing a trait,
* vector of dynamically typed values,
* create thread local connections for multithreaded applications.
Things still missing:
* support for `DECIMAL` types - currently `DECIMAL` columns need to be cast to `DOUBLE` on the query (PR welcome),
* rest of this list - please open issue in `GitHub` issue tracker for missing functionality, bugs, etc..
Example usage
=============
Connect and run one-off queries with row type conversion
-------------
```rust
use odbc_iter::{Odbc, ValueRow};
// Connect to database using connection string
let connection_string = std::env::var("DB_CONNECTION_STRING")
.expect("DB_CONNECTION_STRING environment not set");
let mut connection = Odbc::connect(&connection_string)
.expect("failed to connect to database");
// Handle statically guards access to connection and provides query functionality
let mut db = connection.handle();
// Get single row single column value
println!("{}", db.query::<String>("SELECT 'hello world'").expect("failed to run query")
.single().expect("failed to fetch row"));
// Iterate rows with single column
for row in db.query::<String>("SELECT 'hello world' UNION SELECT 'foo bar'")
.expect("failed to run query") {
println!("{}", row.expect("failed to fetch row"))
}
// Prints:
// hello world
// foo bar
// Iterate rows with multiple columns
for row in db.query::<(String, i8)>(
"SELECT 'hello world', CAST(24 AS TINYINT) UNION SELECT 'foo bar', CAST(32 AS TINYINT)")
.expect("failed to run query") {
let (string, number) = row.expect("failed to fetch row");
println!("{} {}", string, number);
}
// Prints:
// hello world 24
// foo bar 32
// Iterate rows with dynamically typed values using `ValueRow` type that can represent
// any row
for row in db.query::<ValueRow>("SELECT 'hello world', 24 UNION SELECT 'foo bar', 32")
.expect("failed to run query") {
println!("{:?}", row.expect("failed to fetch row"))
}
// Prints:
// [Some(String("hello world")), Some(Tinyint(24))]
// [Some(String("foo bar")), Some(Tinyint(32))]
```