zig-postgres

Light bindings around Postgres libpq

This is tested with zig 0.8

Installing libpg on debian linux

sudo apt-get install libpq-dev

How to install

---

Add this repository as submodule

git submodule add git@github.com:tonis2/zig-postgres.git dependencies/zig-postgres

Add following code lines into your project build.zig

This code adds the package and links required libraries.

    exe.addPackage(.{ .name = "postgres", .path = "/dependencies/zig-postgres/src/postgres.zig" });
    exe.linkSystemLibrary("c");
    exe.linkSystemLibrary("libpq");

Running examples or tests requires db url attribute, for example

zig build test -Ddb=postgresql://db_url

zig build main -Ddb=postgresql://db_url

How to use

---

Connecting to database

    const Pg = @import("postgres").Pg;

    var gpa = std.heap.GeneralPurposeAllocator(.{}){};
    const allocator = &gpa.allocator;
    defer std.debug.assert(!gpa.deinit());

    var db = try Pg.connect(allocator, "postgresql://root@postgresURL:26257?sslmode=disable");

Executing SQL

   const schema =
        \\CREATE DATABASE IF NOT EXISTS root;
        \\CREATE TABLE IF NOT EXISTS users (id INT, name TEXT, age INT);
    ;

    _ = try db.exec(schema);

Inserting data

Be mindful that this query, uses struct name as lowercase letters for table name.

  const Users = struct {
        id: i16,
        name: []const u8,
        age: i16,
    };

 _ = try db.insert(Users{ .id = 1, .name = "Charlie", .age = 20 });
 _ = try db.insert(Users{ .id = 2, .name = "Steve", .age = 25 });
 _ = try db.insert(Users{ .id = 3, .name = "Karl", .age = 25 });


 _ = try db.insert(&[_]Users{
     Users{ .id = 4, .name = "Tony", .age = 25 },
     Users{ .id = 5, .name = "Sara", .age = 32 },
     Users{ .id = 6, .name = "Fred", .age = 11 },
  });

Exec query with values

_ = try db.execValues("SELECT * FROM users WHERE name = {s}", .{"Charlie"});

_ = try db.execValues("INSERT INTO users (id, name, age) VALUES ({d}, {s}, {d})", .{ 5, "Tom", 32 });

Read query results

var result = try db.execValues("SELECT * FROM users WHERE id = {d}", .{2});
var user = result.parse(Users, null).?;

print("{d} \n", .{user.id});
print("{s} \n", .{user.name});

var results = try db.execValues("SELECT * FROM users WHERE age = {d}", .{25});

while (results.parse(Users, null)) |user| {
    print("{s} \n", .{user.name});
}

var result = try db.execValues("SELECT * FROM users WHERE name = {s}", .{"Charlie"});
var user = result.parse(Users, null}).?;

if(user) print("{s} \n", .{user.name});

Many thanks for this repository