PostgresSQL integration

[Kugelschieber]

Add Postgres as database backend. To do this, a new environment variable must be added, all SQL statements must be translated to Postgres and acweb must decide which one to use.

Example: export ACWEB_DB_TYPE=postgres In model/user.go:

import (
    // [...]
    // import os to read the env variable
    "os"
    // [...]
)
// [...]
// add database type specific SQL statements as constants
const (
    user_mysql_delete = "DELETE FROM user WHERE id = :id"
    user_postgres_delete = "DELETE FROM \"user\" WHERE id = $1"
)
// [...]
func (m *User) Remove() error {
    if m.Id == 0 {
        return errors.New("ID must be set")
    }

    // select the query by database type
    // os.Getenv("ACWEB_DB_TYPE") should be outsourced to make sure it's in lowercase
    // and there should be a check on startup a known DB type is set
    var sql string

    if os.Getenv("ACWEB_DB_TYPE") == "mysql" {
        sql = user_mysql_delete
    } else {
        sql = user_postgres_delete
    }

    _, err := session.NamedExec(sql, m)
    return err
}

The main difference between MySQL and Postgres is that table names in Postgres must be surrounded by quotes and variables are passed by $1, $2, ... $n instead of a :name.

[Kugelschieber]

Implemented.