Rust-oracle

This is an Oracle database driver for Rust based on ODPI-C.

Don't use this until the version number reaches to 0.1.0. Version 0.1.0 will be released if no additional incompatible changes are predicted from planned features.

Change Log

0.0.7

The method to prepare statements was changed for future extension.

Changes:

• New methods and structs
  • Statement.returned_values() to support RETURNING INTO clause.
  • StmtParam struct to specify prepared statement parameters.

Incompatible changes:

• Changed Methods

  • Connection.prepare(). The params argument was added.

• Removed methods

  • Statement.set_fetch_array_size(). Use StmtParam::FetchArraySize instead.

0.0.6

Methods for establishing connections were changed in order to avoid incompatible changes when connection pooling is supported in future.

Changes:

• New methods and enums.

  • Connection::connect()
  • ConnParam

• Deprecated methods.

  • Connnection::new(). Use Connection::connect() instead.

Incompatible changes:

• Renamed variants.
  • Error::NoMoreData → Error::NoDataFound
• Removed structs and enums.
  • Connector (connection builder). Use ConnParam in order to specify extra connection parameters instead.
  • AuthMode. Use ConnParam to specify authentication mode instead.
• Methods whose return type was changed from &String to &str.
  • Connection.tag()
  • ColumnInfo.name()
  • DbError.message()
  • DbError.fn_name()
  • DbError.action()
  • ObjectType.schema()
  • ObjectType.name()
  • ObjectTypeAttr.name()
• Methods whose return type was changed from &Vec<...> to &[...].
  • Row.sql_values()
  • ResultSet.column_info()
  • ObjectType.attributes()

0.0.5

New features:

• Add query methods to Connection to fetch rows without using Statement.
  • Connection.query()
  • Connection.query_named()
  • Connection.query_as()
  • Connection.query_as_named()
• Add query_row methods to Statement to fetch a first row without using ResultSet.
  • Statement.query_row()
  • Statement.query_row_named()
  • Statement.query_row_as()
  • Statement.query_row_as_named()

Incompatible changes:

• Merge RowResultSet struct into RowValueResultSet and rename it to ResultSet.

0.0.4

New features:

• Add query methods to Statement to fetch rows as iterator.
  • Statement.query()
  • Statement.query_named()
  • Statement.query_as()
  • Statement.query_as_named()
• Add query_row methods to Connection to fetch a first row without using Statement.
  • Connection.query_row()
  • Connection.query_row_named()
  • Connection.query_row_as()
  • Connection.query_row_as_named()
• Autocommit mode.

Incompatible changes:

• Execute methods fail for select statements. Use query methods instead.
  • Connection.execute()
  • Connection.execute_named()
  • Statement.execute()
  • Statement.execute_named()
• Renamed traits, methods and variants.
  • ColumnValues → RowValue
  • Row.values() → Row.get_as()
  • Row.columns() → Row.sql_values()
  • Error::Overflow → Error::OutOfRange
• Removed methods.
  • Statement.column_count()
  • Statement.column_names()
  • Statement.column_info()
  • Statement.fetch()
  • SqlValue.clone()

Build-time Requirements

• Rust 1.19 or later
• C compiler. See Compile-time Requirements in this document.

Run-time Requirements

• Oracle client 11.2 or later. See ODPI-C installation document.

Usage

Put this in your Cargo.toml:

[dependencies]
oracle = "0.0.7"

When you need to fetch or bind chrono data types, enable chrono feature:

[dependencies]
oracle = { version = "0.0.7", features = ["chrono"] }

Then put this in your crate root:

extern crate oracle;

Examples

Executes select statements and get rows:

use oracle::{Connection, Error};

// Connect to a database.
let conn = Connection::connect("scott", "tiger", "//localhost/XE", &[]).unwrap();

let sql = "select ename, sal, comm from emp where deptno = :1";

// Select a table with a bind variable.
println!("---------------|---------------|---------------|");
let rows = conn.query(sql, &[&30]).unwrap();
for row_result in rows {
    let row = row_result.unwrap();
    // get a column value by position (0-based)
    let ename: String = row.get(0).unwrap();
    // get a column by name (case-insensitive)
    let sal: i32 = row.get("sal").unwrap();
    // Use `Option<...>` to get a nullable column.
    // Otherwise, `Err(Error::NullValue)` is returned
    // for null values.
    let comm: Option<i32> = row.get(2).unwrap();

    println!(" {:14}| {:>10}    | {:>10}    |",
             ename,
             sal,
             comm.map_or("".to_string(), |v| v.to_string()));
}

// Another way to fetch rows.
// The rows iterator returns Result<(String, i32, Option<i32>)>.
println!("---------------|---------------|---------------|");
let rows = conn.query_as::<(String, i32, Option<i32>)>(sql, &[&10]).unwrap();
for row_result in rows {
    let (ename, sal, comm) = row_result.unwrap();
    println!(" {:14}| {:>10}    | {:>10}    |",
             ename,
             sal,
             comm.map_or("".to_string(), |v| v.to_string()));
}

Executes select statements and get the first rows:

use oracle::Connection;

// Connect to a database.
let conn = Connection::connect("scott", "tiger", "//localhost/XE", &[]).unwrap();

let sql = "select ename, sal, comm from emp where empno = :1";

// Print the first row.
let row = conn.query_row(sql, &[&7369]).unwrap();
let ename: String = row.get("empno").unwrap();
let sal: i32 = row.get("sal").unwrap();
let comm: Option<i32> = row.get("comm").unwrap();
println!("---------------|---------------|---------------|");
println!(" {:14}| {:>10}    | {:>10}    |",
         ename,
         sal,
         comm.map_or("".to_string(), |v| v.to_string()));
// When no rows are found, conn.query_row() returns `Err(Error::NoDataFound)`.

// Get the first row as a tupple
let row = conn.query_row_as::<(String, i32, Option<i32>)>(sql, &[&7566]).unwrap();
println!("---------------|---------------|---------------|");
println!(" {:14}| {:>10}    | {:>10}    |",
         row.0,
         row.1,
         row.2.map_or("".to_string(), |v| v.to_string()));

Executes non-select statements:

use oracle::Connection;

// Connect to a database.
let conn = Connection::connect("scott", "tiger", "//localhost/XE", &[]).unwrap();

conn.execute("create table person (id number(38), name varchar2(40))", &[]).unwrap();

// Execute a statement with positional parameters.
conn.execute("insert into person values (:1, :2)",
             &[&1, // first parameter
               &"John" // second parameter
              ]).unwrap();

// Execute a statement with named parameters.
conn.execute_named("insert into person values (:id, :name)",
                   &[("id", &2), // 'id' parameter
                     ("name", &"Smith"), // 'name' parameter
                    ]).unwrap();

// Commit the transaction.
conn.commit().unwrap();

// Delete rows
conn.execute("delete from person", &[]).unwrap();

// Rollback the transaction.
conn.rollback().unwrap();

Prints column information:

use oracle::Connection;

// Connect to a database.
let conn = Connection::connect("scott", "tiger", "//localhost/XE", &[]).unwrap();

let sql = "select ename, sal, comm from emp where 1 = 2";
let rows = conn.query(sql, &[]).unwrap();

// Print column names
for info in rows.column_info() {
    print!(" {:14}|", info.name());
}
println!("");

// Print column types
for info in rows.column_info() {
    print!(" {:14}|", info.oracle_type().to_string());
}
println!("");

Prepared statement:

use oracle::Connection;

let conn = Connection::connect("scott", "tiger", "//localhost/XE", &[]).unwrap();

// Create a prepared statement
let mut stmt = conn.prepare("insert into person values (:1, :2)", &[]).unwrap();
// Insert one row
stmt.execute(&[&1, &"John"]).unwrap();
// Insert another row
stmt.execute(&[&2, &"Smith"]).unwrap();

This is more efficient than two conn.execute(). An SQL statement is executed in the DBMS as follows:

• step 1. Parse the SQL statement and create an execution plan.
• step 2. Execute the plan with bind parameters.

When a prepared statement is used, step 1 is called only once.

NLS_LANG parameter

NLS_LANG consists of three components: language, territory and charset. However the charset component is ignored and UTF-8(AL32UTF8) is used as charset because rust characters are UTF-8.

The territory component specifies numeric format, date format and so on. However it affects only conversion in Oracle. See the following example:

use oracle::Connection;

// The territory is France.
std::env::set_var("NLS_LANG", "french_france.AL32UTF8");
let conn = Connection::connect("scott", "tiger", "", &[]).unwrap();

// 10.1 is converted to a string in Oracle and fetched as a string.
let result = conn.query_row_as::<String>("select to_char(10.1) from dual", &[]).unwrap();
assert_eq!(result, "10,1"); // The decimal mark depends on the territory.

// 10.1 is fetched as a number and converted to a string in rust-oracle
let result = conn.query_row_as::<String>("select 10.1 from dual", &[]).unwrap();
assert_eq!(result, "10.1"); // The decimal mark is always period(.).

Note that NLS_LANG must be set before first rust-oracle function execution if required.

TODO

• Connection pooling
• Read and write LOB as stream
• REF CURSOR, BOOLEAN
• Scrollable cursors
• Batch DML
• Better Oracle object type support

License

Rust-oracle itself is under 2-clause BSD-style license.

ODPI-C bundled in rust-oracle is under the terms of:

1. the Universal Permissive License v 1.0 or at your option, any later version; and/or
2. the Apache License v 2.0.