docs: add a basic custom MySQL2 class exampleusing TypeScript

Author: wellwelwel

documentation/en/TypeScript-Examples.md

@@ -307,4 +307,4 @@ You can also check some code examples using **MySQL2** and **TypeScript** to und
 - [Extending and using **Interfaces** with `RowDataPacket`, `rowAsArray` and `multipleStatements`](../../examples/typescript/row-data-packet-row-as-array-multi-statements.ts)
 - [Checking for `ResultSetHeader`, extending and using **Interfaces** with `RowDataPacket` from `ProcedureCallPacket`](../../examples/typescript/procedure-call-packet.ts)
 - [Checking for `ResultSetHeader`, extending and using **Interfaces** with `RowDataPacket` and `rowAsArray` from `ProcedureCallPacket`](../../examples/typescript/procedure-call-packet-row-as-array.ts)
-- Creating a custom **MySQL2** **Class** (*in progress*)
+- [Creating a basic custom **MySQL2** **Class**](../../examples/typescript/baisc-custom-class.ts)

examples/typescript/baisc-custom-class.ts

@@ -0,0 +1,141 @@
+/**
+ * The types are explicity for learning purpose
+ */
+
+import {
+  createPool,
+  PoolOptions,
+  Pool,
+  ResultSetHeader,
+  RowDataPacket,
+} from 'mysql2/promise';
+
+interface User extends RowDataPacket {
+  id: number;
+  name: string;
+}
+
+class MySQL {
+  private conn: Pool;
+  private credentials: PoolOptions;
+
+  constructor(credentials: PoolOptions) {
+    this.credentials = credentials;
+    this.conn = createPool(this.credentials);
+  }
+
+  /** A random method to simulate a step before to get the class methods */
+  private ensureConnection() {
+    if (!this?.conn) this.conn = createPool(this.credentials);
+  }
+
+  /** For `SELECT` and `SHOW` */
+  get queryRows() {
+    this.ensureConnection();
+    return this.conn.query.bind(this.conn)<RowDataPacket[]>;
+  }
+
+  /** For `SELECT` and `SHOW` with `rowAsArray` as `true` */
+  get queryRowsAsArray() {
+    this.ensureConnection();
+    return this.conn.query.bind(this.conn)<RowDataPacket[][]>;
+  }
+
+  /** For `INSERT`, `UPDATE`, etc. */
+  get queryResult() {
+    this.ensureConnection();
+    return this.conn.query.bind(this.conn)<ResultSetHeader>;
+  }
+
+  /** For multiple `INSERT`, `UPDATE`, etc. with `multipleStatements` as `true` */
+  get queryResults() {
+    this.ensureConnection();
+    return this.conn.query.bind(this.conn)<ResultSetHeader[]>;
+  }
+
+  /** For `SELECT` and `SHOW` */
+  get executeRows() {
+    this.ensureConnection();
+    return this.conn.execute.bind(this.conn)<RowDataPacket[]>;
+  }
+
+  /** For `SELECT` and `SHOW` with `rowAsArray` as `true` */
+  get executeRowsAsArray() {
+    this.ensureConnection();
+    return this.conn.execute.bind(this.conn)<RowDataPacket[][]>;
+  }
+
+  /** For `INSERT`, `UPDATE`, etc. */
+  get executeResult() {
+    this.ensureConnection();
+    return this.conn.execute.bind(this.conn)<ResultSetHeader>;
+  }
+
+  /** For multiple `INSERT`, `UPDATE`, etc. with `multipleStatements` as `true` */
+  get executeResults() {
+    this.ensureConnection();
+    return this.conn.execute.bind(this.conn)<ResultSetHeader[]>;
+  }
+
+  /** Expose the Pool Connection */
+  get connection() {
+    return this.conn;
+  }
+}
+
+(async () => {
+  const access: PoolOptions = {
+    host: '',
+    user: '',
+    password: '',
+    database: '',
+  };
+
+  const mysql = new MySQL(access);
+
+  /** Deleting the `users` table, if it exists */
+  await mysql.queryResult('DROP TABLE IF EXISTS `users`;');
+
+  /** Creating a minimal user table */
+  await mysql.queryResult(
+    'CREATE TABLE `users` (`id` INT(11) AUTO_INCREMENT, `name` VARCHAR(50), PRIMARY KEY (`id`));',
+  );
+
+  /** Inserting some users */
+  const [inserted] = await mysql.executeResult(
+    'INSERT INTO `users`(`name`) VALUES(?), (?), (?), (?);',
+    ['Josh', 'John', 'Marie', 'Gween'],
+  );
+
+  console.log('Inserted:', inserted.affectedRows);
+
+  /** Getting users */
+  const [users] = await mysql.queryRows(
+    'SELECT * FROM `users` ORDER BY `name` ASC;',
+  );
+
+  users.forEach((user: User) => {
+    console.log('-----------');
+    console.log('id:  ', user.id);
+    console.log('name:', user.name);
+  });
+
+  await mysql.connection.end();
+})();
+
+/** Output
+ *
+ * Inserted: 4
+ * -----------
+ * id:   4
+ * name: Gween
+ * -----------
+ * id:   2
+ * name: John
+ * -----------
+ * id:   1
+ * name: Josh
+ * -----------
+ * id:   3
+ * name: Marie
+ */