dstddb 0.0.13

dstddb

A proposed standard database client interface and implementation for the D Language

Status: early stage project - unstable and minimally tested

Available in DUB, the D package registry

Quickstart with Dub

Add a dub.sdl file

name "demo"
libs "sqlite3"
dependency "dstddb" version="*"
versions "StdLoggerDisableLogging"
targetType "executable"

Add a simple example in src/demo.d

void main() {
    import std.database.sqlite;
    auto db = createDatabase("file:///testdb.sqlite");
    auto con = db.connection;
    con.query("drop table if exists score");
    con.query("create table score(name varchar(10), score integer)");
    con.query("insert into score values('Knuth',71)");
    con.query("insert into score values('Dijkstra',82)");
    con.query("insert into score values('Hopper',98)");
    auto rows = con.query("select name,score from score").rows;
    foreach (r; rows) writeln(r[0].as !string, ",", r[1].as !int);
}

Run it:

dub

Roadmap Highlights

• A database and driver neutral interface specification
• Reference counted value objects provide ease of use
• Templated implementations for Phobos compatibility
• Support for direct and polymorphic interfaces
• A range interface for query result sets
• Support a for fluent style interface
• URL style connection strings
• Reference implementations so far: ODBC, sqlite, mysql, oracle, postgres, freetds (MS SQL)
• Support for allocators
• Support for runtime driver registration
• Input variable binding support
• Array input/output binding support
• Connection pooling

Examples

simple query

import std.database.mysql;
auto db = createDatabase("mysql://database");
db.query("insert into table('name',123)");

expanded classic style select

import std.database.mysql;
auto db = createDatabase("mysql://127.0.0.1/test");
auto con = db.connection();
auto stmt = con.statement("select * from table");
auto rows = stmt.query.rows;
foreach (row; rows) {
    for(size_t col = 0; col != row.width; ++col) write(row[col], " ");
    writeln();
}

fluent style select

import std.database.sqlite;
createDatabase("file:///demo.sqlite")
    .connection
    .query("select * from t1")
    .writeRows;

field access

import std.database.sqlite;
auto db = createDatabase("file:///testdb");
auto rows = db.connection.query("select name,score from score").rows;
foreach (r; rows) {
    writeln(r[0].as!string,",",r[1].as!int);
}

select with input binding

import std.database.sqlite;
int minScore = 50;
createDatabase("file:///demo.sqlite")
    .connection
    .query("select * from t1 where score >= ?", minScore)
    .writeRows;

insert with input binding

import std.database;
auto db = createDatabase("mydb");
auto con = db.connection();
auto stmt = con.statement("insert into table values(?,?)");
stmt.query("a",1);
stmt.query("b",2);
stmt.query("c",3);

poly database setup (driver registration)

import std.database.poly;
Database.register!(std.database.sqlite.Database)();
Database.register!(std.database.mysql.Database)();
Database.register!(std.database.oracle.Database)();
auto db = createDatabase("mydb");

Notes

• The reference implementations use logging (std.experimental.logger). To hide the info logging, add this line to your package.json file: "versions": ["StdLoggerDisableInfo"].

Related Work

CPPSTDDB is a related project with similar objectives tailored to the constraints of the C++ language. The aim is for both projects to complement each other by proving the validity of specific design choices that apply to both and to draw on implementation correctness re-enforced from dual language development.