Fixes #97: SQLite is now async, optimized, tests

plugos/sqlite/deno-sqlite/examples/cli.ts

@@ -0,0 +1,79 @@
+/**
+ * cli.ts
+ *
+ * A simple clone of the sqlite3 command line
+ * interface, build using deno-sqlite.
+ *
+ * This is an example, meant to illustrate using
+ * the API provided by deno-sqlite.
+ */
+
+import { readLines, writeAll } from "https://deno.land/std@0.134.0/io/mod.ts";
+import AsciiTable from "https://deno.land/x/ascii_table@v0.1.0/mod.ts";
+import { DB } from "../mod.ts";
+
+const db = new DB(Deno.args[0] ?? undefined);
+
+async function print(str: string) {
+  const enc = new TextEncoder();
+  await writeAll(Deno.stdout, enc.encode(str));
+}
+
+async function prompt() {
+  await print("sqlite> ");
+}
+
+const tablesQuery = db.prepareQuery<[string]>(
+  "SELECT name FROM sqlite_master WHERE type = 'table' AND name NOT LIKE 'sqlite_%'",
+);
+
+const commands: Record<string, () => Promise<void>> = {
+  "tables": async () => {
+    for (const [name] of tablesQuery.iter()) {
+      await print(`${name}\n`);
+    }
+  },
+  "quit": async () => {
+    await print("\n");
+    Deno.exit(0);
+  },
+  "help": async () => {
+    await print(
+      "Type an SQL query or run a command.\nThe following commands are available:\n",
+    );
+    for (const key in commands) {
+      await print(`.${key}\n`);
+    }
+  },
+};
+
+await prompt();
+for await (const cmd of readLines(Deno.stdin)) {
+  if (cmd[0] === ".") {
+    const action = commands[cmd.slice(1)] ??
+      (() => print("Unrecognized command, try .help\n"));
+    await action();
+  } else {
+    try {
+      const query = db.prepareQuery(cmd);
+      const rows = query.all();
+      const cols = query.columns();
+      query.finalize();
+
+      if (cols.length) {
+        const table = new AsciiTable();
+        table.setHeading("#", ...cols.map(({ name }) => name));
+        for (const [idx, row] of rows.entries()) {
+          table.addRow(idx + 1, ...row);
+        }
+        print(table.toString());
+        print("\n");
+      } else {
+        print(`Executed query: ${db.changes} changes\n`);
+      }
+    } catch (err) {
+      console.error(err);
+    }
+  }
+  await prompt();
+}

plugos/sqlite/deno-sqlite/examples/notes.ts

@@ -0,0 +1,57 @@
+/**
+ * notes.ts
+ *
+ * A command line tool to manage a set
+ * of simple notes.
+ *
+ * This is an example, meant to illustrate using
+ * the API provided by deno-sqlite.
+ */
+
+import { DB } from "../mod.ts";
+
+const commands: Record<string, (...args: string[]) => Promise<void> | void> = {
+  "create": (file: string) => {
+    const db = new DB(file, { mode: "create" });
+    db.query(`
+      CREATE TABLE notes (
+        id INTEGER PRIMARY KEY AUTOINCREMENT,
+        note TEXT NOT NULL,
+        created_at TEXT NOT NULL
+      )
+    `);
+    db.close();
+    console.log("Database created!");
+  },
+  "record": (file: string, note: string) => {
+    const db = new DB(file, { mode: "write" });
+    db.query("INSERT INTO notes (note, created_at) VALUES (?, ?)", [
+      note,
+      new Date(),
+    ]);
+    db.close();
+    console.log("Note recorded!");
+  },
+  "delete": (file: string, noteId: string) => {
+    const db = new DB(file, { mode: "write" });
+    db.query("DELETE FROM notes WHERE id = ?", [noteId]);
+    db.close();
+    console.log("Note deleted!");
+  },
+  "list": (file: string) => {
+    const db = new DB(file, { mode: "read" });
+    const query = db.prepareQuery<[number, string, string]>(
+      "SELECT id, note, created_at FROM notes ORDER BY created_at DESC",
+    );
+    for (const [id, note, createdAt] of query.iter()) {
+      const date = new Date(createdAt);
+      console.log(`Note #${id} (recorded ${date.toLocaleString()})\n${note}\n`);
+    }
+    query.finalize();
+    db.close();
+  },
+};
+
+const command = commands[Deno.args[0]] ??
+  (() => console.error(`Unknown command '${Deno.args[0]}'.`));
+await command(...Deno.args.slice(1));

plugos/sqlite/deno-sqlite/examples/server.ts

@@ -0,0 +1,42 @@
+/**
+ * server.ts
+ *
+ * A server which returns the number
+ * of hits to any given path since
+ * the server started running.
+ *
+ * This is an example, meant to illustrate using
+ * the API provided by deno-sqlite.
+ */
+
+import { serve } from "https://deno.land/std@0.134.0/http/mod.ts";
+import { DB } from "../mod.ts";
+
+const db = new DB();
+
+db.query(`
+  CREATE TABLE visits (
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    url TEXT NOT NULL,
+    visited_at TEXT NOT NULL
+  )
+`);
+
+const addVisitQuery = db.prepareQuery(
+  "INSERT INTO visits (url, visited_at) VALUES (:url, :time)",
+);
+const countVisitsQuery = db.prepareQuery<[number]>(
+  "SELECT COUNT(*) FROM visits WHERE url = :url",
+);
+
+console.log("Running server on localhost:8080");
+
+await serve((req) => {
+  addVisitQuery.execute({
+    url: req.url,
+    time: new Date(),
+  });
+
+  const [count] = countVisitsQuery.one({ url: req.url });
+  return new Response(`This page was visited ${count} times!`);
+}, { port: 8080 });