Crud Operations

Common Patterns

CRUD best practices and design patterns

Upsert Pattern

Create or update in one operation:

players:UpdateOne(
    { steamid = steamid },
    {
        ["$set"] = { username = name, last_seen = os.time() },
        ["$setOnInsert"] = { created_at = os.time(), level = 1 }
    },
    true  -- upsert
)

Atomic Counter

-- Safe counter increment
stats:UpdateOne(
    { key = "page_views" },
    { ["$inc"] = { count = 1 } },
    true
)

Conditional Update

-- Purchase only if enough credits
local success = players:UpdateOne(
    {
        steamid = steamid,
        credits = { ["$gte"] = price }
    },
    {
        ["$inc"] = { credits = -price },
        ["$push"] = { purchases = itemId }
    }
)
return success > 0

Pagination

local function GetPage(pageNum, perPage)
    return players:Aggregate({
        { ["$sort"] = { level = -1 } },
        { ["$skip"] = (pageNum - 1) * perPage },
        { ["$limit"] = perPage }
    })
end

Soft Delete

-- Don't delete, mark as deleted
players:UpdateOne(
    { steamid = steamid },
    {
        ["$set"] = {
            deleted = true,
            deleted_at = os.time()
        }
    }
)
-- Query excluding deleted
players:Find({ deleted = { ["$ne"] = true } })

Best Practices

Use upsert for "create or update"
Use atomic operations ($inc, $push) instead of read-modify-write
Add timestamps (created_at, updated_at)
Use indexes on frequently queried fields
Always limit Find queries
Validate data before inserting
Use soft deletes for important data

Query Filters

Advanced MongoDB query operators

Advanced Features

Aggregation, indexes, and advanced operations