error if DATABASE_URL can't be parsed:

DbConnType.from_url() returns error if it fails to parse DATABASE_URL

src/db/mod.rs

@@ -190,14 +190,18 @@ generate_connections! {
 
 impl DbConnType {
     pub fn from_url(url: &str) -> Result<DbConnType, Error> {
-        // Mysql
+        if url.contains(':')
+            && !(url.len() >= 2
+                && url.chars().next().unwrap().is_ascii_alphabetic()
+                && url.chars().nth(1).unwrap() == ':')
+        {
+            // MySQL
             if url.starts_with("mysql:") {
                 #[cfg(mysql)]
                 return Ok(DbConnType::mysql);
 
                 #[cfg(not(mysql))]
                 err!("`DATABASE_URL` is a MySQL URL, but the 'mysql' feature is not enabled")
-
                 // Postgres
             } else if url.starts_with("postgresql:") || url.starts_with("postgres:") {
                 #[cfg(postgresql)]
@@ -205,8 +209,11 @@ impl DbConnType {
 
                 #[cfg(not(postgresql))]
                 err!("`DATABASE_URL` is a PostgreSQL URL, but the 'postgresql' feature is not enabled")
-
+                // Failed to parse
-        //Sqlite
+            } else {
+                err!("`DATABASE_URL` looks like a URI but it could not be parsed, make sure it is valid. Note that ':' in filepaths are disallowed and DATABASE_URL only accepts 'postgresql://', 'postgres://' and 'mysql://' as valid URIs")
+            }
+        // SQLite
         } else {
             #[cfg(sqlite)]
             return Ok(DbConnType::sqlite);