v/vlib/db/pg/README.md

## Description:

`pg` is a wrapper for the PostgreSQL client library. It provides access to a PostgreSQL
database server.

Before you can use this module, you must first have PostgreSQL installed on your system.
To do this, find your OS and perform the actions listed.

> **Note**
> These instructions are meant only as a convenience. If your OS is not listed 
> or you need extra help, [go here](https://www.postgresql.org/download/).

### Fedora 31
```
sudo dnf install postgresql-server postgresql-contrib
sudo systemctl enable postgresql # to autostart on startup
sudo systemctl start  postgresql
```

### Ubuntu/Debian
```
sudo apt-get install postgresql postgresql-client
sudo systemctl enable postgresql # to autostart on startup
sudo systemctl start  postgresql
```

### MacOSX (Homebrew)
```
brew install postgresql
brew services start postgresql
```

### MacOSX (MacPorts)
```
gem install pg -- --with-pg-config=/opt/local/lib/postgresql[version number]/bin/pg_config
```

## Installing libpq-dev or its equivalent for your OS: ##

**Ubuntu/Debian**: `sudo apt-get install libpq-dev`

**Red Hat Linux (RHEL)**: `yum install postgresql-devel`

**OpenSuse**: `zypper in postgresql-devel`

**ArchLinux**: `pacman -S postgresql-libs`

##Getting Started with [PostgreSQL](https://www.postgresqltutorial.com/postgresql-getting-started)

Read this section to learn how to install and connect to PostgreSQL
[*Windows*](https://www.postgresqltutorial.com/install-postgresql);
[*Linux*](https://www.postgresqltutorial.com/postgresql-getting-started/install-postgresql-linux);
[*macOS*](https://www.postgresqltutorial.com/postgresql-getting-started/install-postgresql-macos).

## Using Parameterized Queries

Parameterized queries (exec_param, etc.) in V require the use of the following syntax: ($n). 

The number following the $ specifies which parameter from the argument array to use.

```v ignore
db.exec_param_many('INSERT INTO users (username, password) VALUES ($1, $2)', ['tom', 'securePassword']) or { panic(err) }
db.exec_param('SELECT * FROM users WHERE username = ($1) limit 1', 'tom') or { panic(err) }
```