Zig Sqlite

main.zig

const std = @import("std");
usingnamespace @cImport({
    @cInclude("sqlite3.h");
});

const Error = error{
    CantOpen,
    Error,
    Busy,
    Done,
    Row,
    Misuse,
    Unimplemented,
};

fn cb(data: ?*c_void, argc: c_int, argv: [*c][*c]u8, azColName: [*c][*c]u8) callconv(.C) c_int {
    var i: usize = 0;

    while (i < argc) {
        if (argv[i] != null) {
            std.debug.warn("{s} = {s}\n", .{ azColName[i], argv[i] });
        } else {
            std.debug.warn("{s} = {}\n", .{ azColName[i], "NULL" });
        }
        i += 1;
    }
    std.debug.warn("\n", .{});
    return 0;
}

pub fn main() anyerror!void {
    var raw_db: ?*sqlite3 = undefined;

    if (sqlite3_open("test.db", &raw_db) != 0) {
        std.debug.warn("Could not open sqlite database.", .{});
        return Error.CantOpen;
    }
    defer _ = sqlite3_close(raw_db);

    var db: *sqlite3 = @ptrCast(*sqlite3, raw_db);

    var tb_create_sql: [*:0]const u8 =
        \\ CREATE TABLE IF NOT EXISTS COMPANY(
        \\   ID INT PRIMARY KEY   NOT NULL,
        \\   NAME           TEXT  NOT NULL,
        \\   AGE            INT   NOT NULL,
        \\   ADDRESS        CHAR(50),
        \\   SALARY         REAL );
    ;

    exec(db, tb_create_sql, cb) catch {
        std.debug.warn("Failed to create table.\n", .{});
    };


    var insert_sql: [*:0]const u8 =
        \\ INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY)
        \\ VALUES (1, 'Paul', 32, 'California', 20000.00);
        \\ INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY)
        \\ VALUES (2, 'Allen', 25, 'Texas', 15000.00);
        \\ INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY)
        \\ VALUES (3, 'Teddy', 23, 'Norway', 20000.00);
        \\ INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY)
        \\ VALUES (3, 'Mark', 25, 'Rich-Mond', 65000.00);
    ;
    exec(db, insert_sql, cb) catch {
        std.debug.warn("Failed to insert values.\n", .{});
    };


    var select_sql: [*:0]const u8 = "SELECT * from COMPANY";
    exec(db, select_sql, cb) catch {
        std.debug.warn("Failed to select values.\n", .{});
    };
}

pub fn exec(db: *sqlite3, sql: [*:0]const u8, callback: fn(?*c_void, c_int, [*c][*c]u8, [*c][*c]u8) callconv(.C) c_int) !void {
    var errmsg: ?[*:0]u8 = undefined;
    var rc = sqlite3_exec(db, sql, callback, null, &errmsg);
    switch (rc) {
        SQLITE_OK => {
            return;
        },
        SQLITE_ERROR => {
            return Error.Error;
        },
        else => {
            std.debug.warn("{}: {s}\n", .{rc, errmsg});
            return Error.Unimplemented;
        },
    }
    if (rc != SQLITE_OK) {
        sqlite3_free(errmsg);
    }
}