add exists helper to sqlite wrapper

runner/lua/sqlite.lua

@@ -263,6 +263,21 @@ local connection_mt = {
 			return results[1]
 		end,
 
+		exists = function(self, table_name, where, params, ...)
+			if type(table_name) ~= "string" then
+				error("connection:exists: table_name must be a string", 2)
+			end
+
+			local query = "SELECT 1 FROM " .. table_name
+			if where then
+				query = query .. " WHERE " .. where
+			end
+			query = query .. " LIMIT 1"
+
+			local results = self:query(query, normalize_params(params, ...))
+			return #results > 0
+		end,
+
 		begin = function(self)
 			return self:exec("BEGIN TRANSACTION")
 		end,