duckdb 0.2.0
DuckDB client for D
To use this package, run the following command in your project's root directory:
Manual usage
Put the following dependency into your project's dependences section:
d-duckdb
DuckDB client for D. This client is based on DuckDB's C API.
Usage
Iterate query result via foreach
import duckdb;
import std;
void main()
{
auto db = new Database(null); // null for in-memory database
auto conn = db.connect();
writeln(duckdbVersion);
conn.queryWithoutResult("CREATE TABLE integers (i INTEGER, j INTEGER);");
conn.queryWithoutResult("INSERT INTO integers VALUES (3, 4), (5, 6), (7, NULL);");
auto r = conn.query("SELECT * FROM integers;");
foreach (int a, Nullable!int b; r) // Specify argument types explicitly
writeln(a, ", ", b);
conn.disconnect();
db.close();
}
Prepared Statement
import duckdb;
import std;
void main()
{
auto db = new Database(null); // null for in-memory database
auto conn = db.connect();
writeln(duckdbVersion);
conn.queryWithoutResult("CREATE TABLE integers (i SMALLINT, j BIGINT);");
auto stmt1 = conn.prepare("INSERT INTO integers VALUES ($i, $j)");
foreach (i; 0..10) {
short n1 = cast(short)i;
long n2 = long.max - i;
stmt1.bindInt16(1, n1);
stmt1.bindInt64(2, n2);
stmt1.execute();
}
stmt1.destroy();
auto stmt2 = conn.prepare("SELECT * FROM integers WHERE i BETWEEN ? AND ?;");
stmt2.bindValues(3, 8); // bindValues is shorter than calling each bindXXX
foreach (short i, long j; stmt2.execute())
writeln(i, " : ", j);
stmt2.destroy();
conn.disconnect();
db.close();
}
Appender: Faster bulk insertion
import duckdb;
import std;
void main()
{
auto db = new Database(null); // null for in-memory database
auto conn = db.connect();
writeln(duckdbVersion);
conn.queryWithoutResult("CREATE TABLE apps (i SMALLINT, str VARCHAR, ts TIMESTAMP);");
auto appender = conn.appender("apps");
foreach (i; 0..3)
appender.appendRow(i, text("Name", i), Clock.currTime);
appender.destroy();
auto r = conn.query("SELECT * FROM apps;");
foreach (short i, string str, SysTime ts; r)
writeln("id: ", i, ", name: ", str, ", timestampe: ", ts);
r.destroy();
conn.disconnect();
db.close();
}
DuckDB and D Types
DuckDB type | D type | Description |
---|---|---|
BOOLEAN | bool | |
TINYINT | byte | |
SMALLINT | short | |
INTEGER | int | |
BIGINT | long | |
HUGEINT | std.bigint.BigInt | |
UTINYINT | ubyte | |
USMALLINT | ushort | |
UINTEGER | uint | |
UBIGINT | ulong | |
UHUGEINT | std.bigint.BigInt | |
FLOAT | float | |
DOUBLE | double | |
DECIMAL | TODO: Phobos doesn't have BigFloat/BigDecimal, so support is limited | |
VARCHAR | string/wstring/dstring | |
BLOB | byte[] | |
BITSTRING | string | |
ENUM | string | |
DATE | std.datetime.Date | |
TIME | TODO but use TIMESTAMP instead | |
TIMESTAMP | std.datetime.SysTime | |
TIMESTAMPTZ | std.datetime.SysTime | |
TIMESTAMP_S | std.datetime.SysTime | |
TIMESTAMP_MS | std.datetime.SysTime | |
TIMESTAMP_NS | TIMESTAMP_NS is not supported because SysTime is hnsecs precision | |
INTERVAL | TODO | |
ARRAY | T[] | |
LIST | T[] | |
MAP | V[K] | |
STRUCT | struct | Current implementation doesn't check field names |
UNION | TODO | |
UUID | std.uuid.UUID |
Special cases
- NULL
Use std.typecons.Nullable
to accept NULL for basic types, e.g. Nullable!int
.
Without Nullable
, client returns .init
value.
- Infinity for DATA and TIMESTAMP
Infinity
/-Infinity
is mapping to .init
value, e.g. Date.init
and SysTime.init
.
TODO
- Support TODO DuckDB types
- Support more APIs
- Improve API design
- Add unittests
Links
DuckDB official site
DuckDB C API document
Copyright
Copyright (c) 2024- Masahiro Nakagawa
License
Distributed under the Boost Software License, Version 1.0.
- Registered by Masahiro Nakagawa
- 0.2.0 released 22 days ago
- repeatedly/d-duckdb
- github.com/repeatedly/d-duckdb
- BSL-1.0
- Copyright © 2024, Masahiro Nakagawa
- Authors:
- Dependencies:
- none
- Versions:
-
0.2.0 2024-Oct-10 0.1.0 2024-Oct-07 0.0.1 2024-Oct-03 ~main 2024-Oct-18 - Download Stats:
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- Score:
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- Short URL:
- duckdb.dub.pm