From 2a91ca04b1e957cd87ed32b7b7432aea706d94ca Mon Sep 17 00:00:00 2001 From: Leah Alpert Date: Fri, 1 Mar 2019 15:23:10 -0800 Subject: [PATCH] Some updates to MongoDB Guided Practice --- databases/mongo-db.md | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/databases/mongo-db.md b/databases/mongo-db.md index 296c464b5..de1d9d62c 100644 --- a/databases/mongo-db.md +++ b/databases/mongo-db.md @@ -28,6 +28,7 @@ Not all data can be or should be stored in a relational way. In those cases, it - [TutorialsPoint MongoDB Tutorial](http://www.tutorialspoint.com/mongodb/) - [MongoDB Full Tutorial w/ Node.js, Express, and Mongoose](https://youtu.be/4yqu8YF29cU) +- [MongoDB Shell commands reference](https://docs.mongodb.com/manual/reference/mongo-shell/) ### Lesson @@ -53,7 +54,7 @@ If no Homebrew-related text appears, you'll need to install Homebrew. Go to the 3. Install MongoDB using `brew install mongodb` in the Terminal. If you get an error message saying you need to install Xcode from the App Store, follow the instructions to do so and then re-try `brew install mongodb`. Ask for help if needed. -4. Make sure you have the directory /data/db. If not, run `sudo mkdir -p /data/db`. If this doesn't work, then try `brew services start mongodb` +4. MongoDB will store data in a directory called /data/db. Check if you have the directory /data/db. If not, run `sudo mkdir -p /data/db`. If this doesn't work, then try `brew services start mongodb` 5. Run `whoami` to find your username. For example, if your username is "myname", then you will run the following command `sudo chown myname /data/db`. You may need to enter your password. 6. If a ~/.bash_profile exists, open it. If not, create one by `touch .bash_profile`. Open your .bash_profile in your text editor and copy the following into the file: - `export MONGO_PATH=/usr/local/mongodb` @@ -63,11 +64,13 @@ If no Homebrew-related text appears, you'll need to install Homebrew. Go to the 8. Keep the first window open with `mongod` still running. Switch to second terminal window, run `mongo --host 127.0.0.1:27017`. This is your Mongo shell. **Activity 2: Working with Database** -- In the shell, run `use techtonica`. Then run `show dbs`, which will list out the list of databases. What database is there? What is missing? +- The command `use ` sets the current database you'll be working with. In the shell, run `use techtonica`. Then run `show dbs`, which will list out the list of databases. What database is there? What is missing? -- The newly created database, "techtonica", should be missing. This is because the techtonica database is empty. Insert a document by running `db.classmates.insert({"name": "your_name", "month": your_birthmonth})`. Do it at least two more times with a friend's name. Remember not to double-quote the birth month to keep it as a digit instead of string. +- The newly created database, "techtonica", should be missing. This is because the `techtonica` database is empty. Let's insert some data storing people's name (as a string) and birth month (as an integer). Insert a document by running `db.classmates.insert({"name": "your_name", "month": your_birthmonth})`. Do it at least two more times with a friend's name. Remember not to double-quote the birth month to keep it as a digit instead of string. -- MongoDB stores documents in collections. Run `show collections`. What is already there? Can you guess at least where one of the collections came from? +- Type `show dbs` again and see that the `techtonica` database now shows up. + +- MongoDB stores documents in collections. Run `show collections`. What is already there? Where did it come from? - Run `db.createCollection("volunteer")`. @@ -75,7 +78,7 @@ If no Homebrew-related text appears, you'll need to install Homebrew. Go to the - Fix the empty volunteer collection by entering a document: `db.volunteers.insert({"volunteer": "Adrien"})` and `db.volunteers.insert({"volunteer": "Jamie"})`. -- Select a number between your birth month and your pair's birth month inside the classmates collection. Run `db.classmates.remove({"month": {$lt: the_number_your_selected}})`. The "$lt" means "less than." What do you think happened to the collections? +- Now we'll try out the `remove` command. Select a number between your birth month and your pair's birth month inside the classmates collection. Run `db.classmates.remove({"month": {$lt: the_number_your_selected}})`. The "$lt" means "less than." What do you think happened to the collections? - Run `db.classmates.find()`. Were you correct?