Скачать или смотреть How to Rename MongoDB Collections Dynamically with Mongo Shell CollectionUpgrade Script

Discover how to write a JavaScript script for Mongo Shell to dynamically rename MongoDB collections based on naming conventions and versioning.
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A Guide to Renaming MongoDB Collections Using Shell Scripts

When dealing with large databases, maintaining an organized structure is key to ensuring smooth operations. In MongoDB, collections often go through various upgrade stages, which can lead to varying naming conventions. This becomes particularly tricky when you want to rename collections based on part of their name and compare against a version schema. If you have collections named similar to CollectionUpgrade_20, CollectionUpgrade_21, and so on, and need to rename collections above a certain schema version, you're in the right place!

In this guide, we will walk through how to use a JavaScript script in the Mongo Shell to achieve this. You’ll learn how to filter collection names, separate their version numbers, and rename those that exceed a specified version. Let's break down the solution into manageable sections.

The Problem

You might have encountered the following situation:

You want to filter and list all collections containing CollectionUpgrade related to versioning.

You need to determine which collections have higher version numbers than your defined schema version (e.g., 28).

Collections like usersCollectionUpgrade_30 or usersCollectionUpgrade_31 should be renamed to usersCollectionUpgrade_30_old and usersCollectionUpgrade_31_old respectively.

For example, given a sample of collection names in your MongoDB setup:

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You want to target usersCollectionUpgrade_30 and usersCollectionUpgrade_31 for renaming.

Solution: Writing the Script

To tackle this problem, you can write the following JavaScript script to run in the Mongo Shell.

Step 1: Define the Current Version

First, obtain the current schema version for comparison. Consider using a password prompt or a hardcoded current version for simplicity.

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Step 2: Identify Collections Matching the Pattern

Next, define a function to filter collection names that start with CollectionUpgrade.

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Step 3: Determine Older Versions

You need to further filter collections to find those that exceed the current version specified.

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Step 4: Rename Collections

Create a function that will rename the selected collections by appending _old to the current collection name.

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Step 5: Execute The Script

Finally, combine all the steps and execute the script to filter, evaluate, and rename collections.

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Putting It All Together

When you compile these segments, your complete script will look like this:

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Conclusion

This script allows you to manage your MongoDB collections dynamically based on naming conventions and version levels. By following these steps, you ensure that no collections with versions beyond your schema version remain in your database with their original names, keeping your collections organized and manageable. Happy coding!