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/++
D2SQLite3 provides a thin and convenient wrapper around the SQLite C API.
Features:
$(UL
$(LI Use reference-counted structs (`Database`, `Statement`) instead of SQLite objects
pointers.)
$(LI Run multistatement SQL code with `Database.run()`.)
$(LI Use built-in integral types, floating point types, `string`, `immutable(ubyte)[]` and
`Nullable` types directly: conversions to and from SQLite types is automatic and GC-safe.)
$(LI Bind multiple values to a prepare statement with `Statement.bindAll()` or
`Statement.inject()`. It's also possible to bind the fields of a struct automatically with
`Statement.inject()`.)
$(LI Handle the results of a query as a range of `Row`s, and the columns of a row
as a range of `ColumnData` (equivalent of a `Variant` fit for SQLite types).)
$(LI Access the data in a result row directly, by index or by name,
with the `Row.peek!T()` methods.)
$(LI Make a struct out of the data of a row with `Row.as!T()`.)
$(LI Register D functions as SQLite callbacks, with `Database.setUpdateHook()` $(I et al).)
$(LI Create new SQLite functions, aggregates or collations out of D functions or delegate,
with automatic type converions, with `Database.createFunction()` $(I et al).)
$(LI Store all the rows and columns resulting from a query at once with the `cached` function
(sometimes useful even if not memory-friendly...).)
$(LI Use an unlock notification when two or more connections access the same database in
shared-cache mode, either using SQLite's dedicated API (sqlite_unlock_notify) or using an
emulated equivalent.)
)
Authors:
Nicolas Sicard (biozic) and other contributors at $(LINK https://github.com/biozic/d2sqlite3)
Copyright:
Copyright 2011-18 Nicolas Sicard.
License:
$(LINK2 http://www.boost.org/LICENSE_1_0.txt, Boost License 1.0).
+/
module d2sqlite3;
public import d2sqlite3.library;
public import d2sqlite3.database;
public import d2sqlite3.statement;
public import d2sqlite3.results;
public import d2sqlite3.sqlite3;
///
unittest // Documentation example
{
// Note: exception handling is left aside for clarity.
import d2sqlite3;
import std.typecons : Nullable;
// Open a database in memory.
auto db = Database(":memory:");
// Create a table
db.run("DROP TABLE IF EXISTS person;
CREATE TABLE person (
id INTEGER PRIMARY KEY,
name TEXT NOT NULL,
score FLOAT
)");
// Prepare an INSERT statement
Statement statement = db.prepare(
"INSERT INTO person (name, score)
VALUES (:name, :score)"
);
// Bind values one by one (by parameter name or index)
statement.bind(":name", "John");
statement.bind(2, 77.5);
statement.execute();
statement.reset(); // Need to reset the statement after execution.
// Bind muliple values at the same time
statement.bindAll("John", null);
statement.execute();
statement.reset();
// Bind, execute and reset in one call
statement.inject("Clara", 88.1);
// Count the changes
assert(db.totalChanges == 3);
// Count the Johns in the table.
auto count = db.execute("SELECT count(*) FROM person WHERE name == 'John'")
.oneValue!long;
assert(count == 2);
// Read the data from the table lazily
ResultRange results = db.execute("SELECT * FROM person");
foreach (Row row; results)
{
// Retrieve "id", which is the column at index 0, and contains an int,
// e.g. using the peek function (best performance).
auto id = row.peek!long(0);
// Retrieve "name", e.g. using opIndex(string), which returns a ColumnData.
auto name = row["name"].as!string;
// Retrieve "score", which is at index 2, e.g. using the peek function,
// using a Nullable type
auto score = row.peek!(Nullable!double)(2);
if (!score.isNull)
{
// ...
}
}
}
|
