https://github.com/rluba/jai-postgres
Mimimal Postgresql client for Jai
https://github.com/rluba/jai-postgres
Last synced: 3 months ago
JSON representation
Mimimal Postgresql client for Jai
- Host: GitHub
- URL: https://github.com/rluba/jai-postgres
- Owner: rluba
- License: mit
- Created: 2020-11-16T14:50:04.000Z (over 4 years ago)
- Default Branch: master
- Last Pushed: 2025-02-24T16:48:32.000Z (5 months ago)
- Last Synced: 2025-02-24T17:46:35.749Z (5 months ago)
- Size: 104 KB
- Stars: 15
- Watchers: 3
- Forks: 6
- Open Issues: 1
-
Metadata Files:
- Readme: readme.md
- License: LICENSE
Awesome Lists containing this project
README
# Mimimal Postgresql client for Jai
This module contains `libpq` bindings as well as some higher-level functions for…
* … connecting to a Postgresql database,
* … executing parameterized queries and
* … optionally parsing the results into a typed array.
It only supports synchronous execution for now.
## Usage
First connect to a Postgresql instance using a connection uri string:
```Jai
connection_str := "postgres://:@:/";
conn, success := connect(connection_str);
defer disconnect(conn);
```
Then use `conn` to execute statements…
```Jai
// Restrict schema access
success = execute(conn, "SELECT pg_catalog.set_config('search_path', 'public', false)");
```
… or execute a query and automatically parse the result into an array of any given type:
```Jai
query :: #string END
SELECT * FROM tourist_attractions
WHERE city = $1 AND price < $2 AND min_age < $3
ORDER BY name
END
Attraction :: struct {
name: string;
city: string;
price: string; // Numerics are parsed into strings
min_age: int;
is_open: bool;
}
// Query parameters can be passed as variadic args after `query`:
city := "Vienna";
price := 50;
min_age := 18;
attractions, success = execute(conn, Attraction, query, city, price, min_age);
```
By default, `execute` fails if the result contains a column that has no corresponding member in the struct type you passed.
You can pass `ignore_unknown = true` to `execute(…)` to ignore unknown columns instead.
If your struct type contains members that aren’t present in the result (or are null), they will be left at their default values.
## Memory model
You’re responsible for freeing everything (including strings) in the result array.
Using a Pool allocator around your `execute` calls might be a good idea.
## Supported query parameter types
* All integer types
* `float` and `float64`
* `string`
## Supported return value column types
* `INT2`, `INT4`, `INT8`
* `FLOAT4`, `FLOAT8`
* `NUMERIC` (currently only parsed into `string` fields)
* `BOOL`
* `CHAR`, `BPCHAR`, `VARCHAR`, `NAME`, `TEXT`
* `DATE`, `TIMESTAMP`, `TIMESTAMPTZ`
* `BYTEA`
* `OID`
* Custom enum types (`CREATE TYPE … AS ENUM`), which can be parsed into `string` or `enum` member fields.