Add Ormin ORM support for BaraDB (Nim client)

clients/nim/ormin/examples/tweeter/src/database.nim

@@ -0,0 +1,51 @@
+import times, strutils, strformat, sequtils
+from db_connector/db_sqlite import instantRows, `[]`
+import ../../../ormin
+import model
+
+importModel(DbBackend.sqlite, "tweeter_model")
+var db {.global.} = open("tweeter.db", "", "", "")
+
+proc findUser*(username: string, user: var User): bool =
+  let res = query:
+    select user(username)
+    where username == ?username
+  echo res
+  if res.len == 0: return false
+  else: user.username = res[0]
+
+  let following = query:
+    select following(followed_user)
+    where follower == ?username
+  user.following = following.filterIt(it.len != 0)
+
+  return true
+
+proc create*(user: User) =
+  query:
+    insert user(username = ?user.username)
+
+proc post*(message: Message) =
+  if message.msg.len > 140:
+    raise newException(ValueError, "Message has to be less than 140 characters.")
+  query:
+    insert message(username = ?message.username,
+                   time = ?message.time,
+                   msg = ?message.msg)
+
+proc follow*(follower, user: User) =
+  query:
+    insert following(follower = ?follower.username, followed_user = ?user.username)
+
+proc findMessage*(usernames: openArray[string], limit = 10): seq[Message] =
+  result = @[]
+  if usernames.len == 0: return
+  var whereClause = "WHERE "
+  for i in 0 ..< usernames.len:
+    whereClause.add("trim(username) = ?")
+    if i < usernames.len - 1:
+      whereClause.add(" or ")
+
+  let s = &"SELECT username, time, msg FROM Message {whereClause} ORDER BY time DESC LIMIT {limit}"
+  for row in db.instantRows(sql(s), usernames):
+    result.add((username: row[0], time: row[1].parseInt, msg: row[2]))