Update README.md (#43)

Author: doubaokun

README.md

@@ -1,17 +1,46 @@
-### install
-
- 1. Make sure you have installed the latest version of swoole (swoole version >= 4.4)
-
- 2. build:
-    ``` 
-    phpize  
-    ./configure
-    make && make install
-    ```
- 3. edit your php.ini :
-     ```
-     extension=swoole_postgresql.so
-     ```
+# Swoole Coroutine Postgres Client
+
+`ext-postgresql` is the Swoole Postgres Client library can be used with in the coroutine context without blocking.
+
+### Pre-requirement
+
+* `libpq` is required
+* `swoole` version >= 4.4.0
+
+### Build & Installation
+
+```bash
+git clone [email protected]:swoole/ext-postgresql.git
+phpize
+./configure
+make && make install
+```
+
+Enable `swoole_postgresql` in php.ini by adding the following line:
+```
+extension=swoole_postgresql.so
+```
+
+### How to use the Postgres Client
+
+```php
+<?php
+Co\run(function () {
+    $db = new Swoole\Coroutine\PostgreSQL();
+    $db->connect("host=127.0.0.1 port=5432 dbname=test user=root password=password");
+    $db->prepare('fortunes', 'SELECT id, message FROM Fortune');
+    $res = $db->execute('fortunes', []);
+    $arr = $db->fetchAll($res);
+    var_dump($arr);
+
+    $db->prepare('select_query', 'SELECT id, randomnumber FROM World WHERE id = $1');
+    $res = $db->execute('select_query', [123]);
+    $ret = $db->fetchAll($res);
+    var_dump($ret);
+});
+```
+
+You can find more examples in the `/examples` folder.