Name: postgrex
Owner: Rainforest QA
Description: PostgreSQL driver for Elixir
Created: 2016-08-30 22:17:52.0
Updated: 2016-08-30 22:17:54.0
Pushed: 2016-08-30 15:57:14.0
Homepage: http://hexdocs.pm/postgrex/
Size: 1100
Language: Elixir
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PostgreSQL driver for Elixir.
Documentation: http://hexdocs.pm/postgrex/
{:ok, pid} = Postgrex.start_link(hostname: "localhost", username: "postgres", password: "postgres", database: "postgres")
, #PID<0.69.0>}
Postgrex.query!(pid, "SELECT user_id, text FROM comments", [])
tgrex.Result{command: :select, empty?: false, columns: ["user_id", "text"], rows: [[3,"hey"],[4,"there"]], size: 2}}
Postgrex.query!(pid, "INSERT INTO comments (user_id, text) VALUES (10, 'heya')", [])
tgrex.Result{command: :insert, columns: nil, rows: nil, num_rows: 1}}
Postgrex is currently on 0.x beta releases. We are heading towards a stable release soon. Please consult the issues tracker for more information and outstanding issues.
PostgreSQL Elixir
---------- ------
NULL nil
bool true | false
char "é"
int 42
float 42.0
text "eric"
bytea <<42>>
numeric #Decimal<42.0> *
date %Postgrex.Date{year: 2013, month: 10, day: 12}
time(tz) %Postgrex.Time{hour: 0, min: 37, sec: 14, usec: 0} **
timestamp(tz) %Postgrex.Timestamp{year: 2013 month: 10, day: 12, hour: 0, min: 37, sec: 14, usec: 0} **
interval %Postgrex.Interval{months: 14, days: 40, secs: 10920}
array [1, 2, 3]
composite type {42, "title", "content"}
range %Postgrex.Range{lower: 1, upper: 5}
uuid <<160,238,188,153,156,11,78,248,187,109,107,185,189,56,10,17>>
hstore %{"foo" => "bar"}
oid types 42
* Decimal
** Timezones will always be normalized to UTC or assumed to be UTC when no information is available, either by PostgreSQL or Postgrex
Postgrex does not automatically cast between types. For example, you can't pass a string where a date is expected. To add type casting, support new types, or change how any of the types above are encoded/decoded, you can use extensions.
Extensions are used to extend Postgrex' built-in type encoding/decoding.
Here is a JSON extension that supports encoding/decoding Elixir maps to the Postgres' JSON type.
To use the extension pass it to the connection as seen below:
grex.start_link(extensions: [{Postgrex.Extensions.JSON, library: Poison}], ...)
PostgreSQL's wire protocol supports encoding types either as text or as binary. Unlike most client libraries Postgrex uses the binary protocol, not the text protocol. This allows for efficient encoding of types (e.g. 4-byte integers are encoded as 4 bytes, not as a string of digits) and automatic support for arrays and composite types.
Unfortunately the PostgreSQL binary protocol transports OID types as integers while the text protocol transports them as string of their name, if one exists, and otherwise as integer.
This means you either need to supply oid types as integers or perform an explicit cast (which would be automatic when using the text protocol) in the query.
ils since $1 is regclass not text.
y("select nextval($1)", ["some_sequence"])
rform an explicit cast, this would happen automatically when using a
ient library that uses the text protocol.
y("select nextval($1::text::regclass)", ["some_sequence"])
termine the oid once and store it for later usage. This is the most
ficient way, since PostgreSQL only has to perform the lookup once. Client
braries using the text protocol do not support this.
ws: [{sequence_oid}]} = query("select $1::text::regclass", ["some_sequence"])
y("select nextval($1)", [sequence_oid])
When using PgBouncer with transaction or statement pooling named prepared queries can not be used because the bouncer may route requests from the same postgrex connection to different PostgreSQL backend processes and discards named queries after the transactions closes. To force unnamed prepared queries:
grex.start_link(prepare: :unnamed)
To contribute you need to compile Postgrex from source and test it:
t clone https://github.com/elixir-ecto/postgrex.git
postgrex
x test
The tests requires some modifications to your hba file. The path to it can be found by running $ psql -U postgres -c "SHOW hba_file" in your shell. Put the following above all other configurations (so that they override):
all postgrex_md5_pw 127.0.0.1/32 md5
all postgrex_cleartext_pw 127.0.0.1/32 password
The server needs to be restarted for the changes to take effect. Additionally you need to setup a Postgres user with the same username as the local user and give it trust or ident in your hba file. Or you can export $PGUSER and $PGPASSWORD before running tests.
Postgres versions 9.0 does not have the CREATE EXTENSION commands. This means we have to locate the postgres installation and run the hstore.sql in contrib to install hstore. Below is an example command to test 9.0 on OS X with homebrew installed postgres:
VERSION=9.0 PGPATH=/usr/local/share/postgresql9/ mix test
Copyright 2013 Eric Meadows-Jönsson
Licensed under the Apache License, Version 2.0 (the “License”); you may not use this file except in compliance with the License. You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an “AS IS” BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.