[−][src]Crate oracle
This is an Oracle database driver for Rust based on ODPI-C.
Applications using Rust-oracle 0.1.x should use 0.2.x. The incompatibility between 0.1.x and 0.2.x is trivial so they will work well without modification. The author continues updating 0.2.x to fix bugs as long as it doesn't introduce incompatibilities.
New features are added in Rust-oracle 0.3.x or later. There are enormous
incompatibilities between 0.2.x and 0.3.x. They were introduced to follow
Rust way. Some parameters were removed and builder data types were added
instead. Some types were moved to a new module sql_type
.
Rust-oracle 0.4.x will include breaking changes about query methods.
The query methods with as
may be renamed to and merged into methods
without as
. The params
argument of Connection.prepare
will be
replaced with some kind of the builder pattern.
Change Log
See ChangeLog.md.
Build-time Requirements
- Rust 1.31.0 or later for rust-oracle 0.3.0 and later.
- Rust 1.19.0 or later for rust-oarcle 0.1.x and 0.2.x.
- 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 = "0.3.0"
When you need to fetch or bind chrono
data types, enable chrono
feature:
[dependencies]
oracle = { version = "0.3.0", features = ["chrono"] }
Then put this in your crate root:
extern crate oracle;
Examples
Executes select statements and get rows:
// Connect to a database. let conn = Connection::connect("scott", "tiger", "//localhost/XE")?; 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])?; for row_result in rows { let row = row_result?; // get a column value by position (0-based) let ename: String = row.get(0)?; // get a column by name (case-insensitive) let sal: i32 = row.get("sal")?; // Use `Option<...>` to get a nullable column. // Otherwise, `Err(Error::NullValue)` is returned // for null values. let comm: Option<i32> = row.get(2)?; 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])?; for row_result in rows { let (ename, sal, comm) = row_result?; 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")?; let sql = "select ename, sal, comm from emp where empno = :1"; // Print the first row. let row = conn.query_row(sql, &[&7369])?; let ename: String = row.get("empno")?; let sal: i32 = row.get("sal")?; let comm: Option<i32> = row.get("comm")?; 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])?; 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")?; conn.execute("create table person (id number(38), name varchar2(40))", &[])?; // Execute a statement with positional parameters. conn.execute("insert into person values (:1, :2)", &[&1, // first parameter &"John" // second parameter ])?; // Execute a statement with named parameters. conn.execute_named("insert into person values (:id, :name)", &[("id", &2), // 'id' parameter ("name", &"Smith"), // 'name' parameter ])?; // Commit the transaction. conn.commit()?; // Delete rows conn.execute("delete from person", &[])?; // Rollback the transaction. conn.rollback()?;
Prints column information:
use oracle::Connection; // Connect to a database. let conn = Connection::connect("scott", "tiger", "//localhost/XE")?; let sql = "select ename, sal, comm from emp where 1 = 2"; let rows = conn.query(sql, &[])?; // 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")?; // Create a prepared statement let mut stmt = conn.prepare("insert into person values (:1, :2)", &[])?; // Insert one row stmt.execute(&[&1, &"John"])?; // Insert another row stmt.execute(&[&2, &"Smith"])?;
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", "")?; // 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", &[])?; 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", &[])?; 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 and ODPI-C bundled in rust-oracle are under the terms of:
Modules
sql_type | SQL data types |
Structs
ColumnInfo | Column information in a select statement |
Connection | Connection to an Oracle database |
Connector | Builder data type to create Connection. |
DbError | Oracle database error or ODPI-C error |
ParseOracleTypeError | An error when parsing a string into an Oracle type fails. This appears only in boxed data associated with Error::ParseError. |
ResultSet | Result set |
Row | Row in a result set of a select statement |
SqlValue | A type containing an Oracle value |
Statement | Statement |
Version | Oracle version information |
Enums
ConnStatus | Connection status |
Error | Enum listing possible errors from rust-oracle. |
Privilege | |
ShutdownMode | Database shutdown mode |
StartupMode | Database startup mode |
StatementType | Statement type returned by Statement.statement_type(). |
StmtParam | Parameters to prepare Statement. |
Traits
BindIndex | A trait implemented by types that can index into bind values of a statement. |
ColumnIndex | A trait implemented by types that can index into columns of a row. |
RowValue | A trait to get a row as specified type |
Type Definitions
Result |