MySQL examples (#501)

* Update README.md

* Update index.ts

plugins/sql/README.md

@@ -65,6 +65,37 @@ const db = await Database.load("postgres://postgres:password@localhost/test");
 await db.execute("INSERT INTO ...");
 ```
 
+## Syntax
+
+We use sqlx as our underlying library, adopting their query syntax:
+
+- sqlite and postgres use the "$#" syntax when substituting query data
+- mysql uses "?" when substituting query data
+
+```javascript
+// INSERT and UPDATE examples for sqlite and postgres
+const result = await db.execute(
+  "INSERT into todos (id, title, status) VALUES ($1, $2, $3)",
+  [todos.id, todos.title, todos.status],
+);
+
+const result = await db.execute(
+  "UPDATE todos SET title = $1, completed = $2 WHERE id = $3",
+  [todos.title, todos.status, todos.id],
+);
+
+// INSERT and UPDATE examples for mysql
+const result = await db.execute(
+  "INSERT into todos (id, title, status) VALUES (?, ?, ?)",
+  [todos.id, todos.title, todos.status],
+);
+
+const result = await db.execute(
+  "UPDATE todos SET title = ?, completed = ? WHERE id = ?",
+  [todos.title, todos.status, todos.id],
+);
+```
+
 ## Contributing
 
 PRs accepted. Please make sure to read the Contributing Guide before making a pull request.

plugins/sql/guest-js/index.ts

@@ -76,10 +76,29 @@ export default class Database {
    *
    * @example
    * ```ts
+   * // for sqlite & postgres
+   * // INSERT example
+   * const result = await db.execute(
+   *    "INSERT into todos (id, title, status) VALUES ($1, $2, $3)",
+   *    [ todos.id, todos.title, todos.status ]
+   * );
+   * // UPDATE example
    * const result = await db.execute(
    *    "UPDATE todos SET title = $1, completed = $2 WHERE id = $3",
    *    [ todos.title, todos.status, todos.id ]
    * );
+   *
+   * // for mysql
+   * // INSERT example
+   * const result = await db.execute(
+   *    "INSERT into todos (id, title, status) VALUES (?, ?, ?)",
+   *    [ todos.id, todos.title, todos.status ]
+   * );
+   * // UPDATE example
+   * const result = await db.execute(
+   *    "UPDATE todos SET title = ?, completed = ? WHERE id = ?",
+   *    [ todos.title, todos.status, todos.id ]
+   * );
    * ```
    */
   async execute(query: string, bindValues?: unknown[]): Promise<QueryResult> {
@@ -91,23 +110,27 @@ export default class Database {
         values: bindValues ?? [],
       },
     );
-
     return {
       lastInsertId,
       rowsAffected,
     };
   }
-
   /**
    * **select**
    *
    * Passes in a SELECT query to the database for execution.
    *
    * @example
    * ```ts
+   * // for sqlite & postgres
    * const result = await db.select(
    *    "SELECT * from todos WHERE id = $1", id
    * );
+   *
+   * // for mysql
+   * const result = await db.select(
+   *    "SELECT * from todos WHERE id = ?", id
+   * );
    * ```
    */
   async select<T>(query: string, bindValues?: unknown[]): Promise<T> {