Hi everyone, this time I have a task related to database storage on firebase firestore. While researching on how to design database on Firestore, I found a good one of this database, so I wanted to write a short share. Let’s start!!!
First, let’s take a look at Firestore’s definition, “flexible, scalable NoSQL cloud database to store and sync data for client- and server-side development”.
From the definition, we can see Firestore is a NoSQL database, ie the database has no relationship, similar to MongoDB . A table in Firestore is a collection and a record is a document. Firebase structure the database as a file system, so if you want to see the document with id doc of collection col then you just need to enter /col/doc into console.
From the way the data is structured in the form of a file system, firebase generates a data type – Reference. This data type works quite similar to Foreign Key strong Relational Datatbase. For example, you have a League table that stores league information and a Club stores club information. Normally, we will save the league_id field in the club table. To find out which club has id 1 playing, you will need to use 2 queries.
1 2 3 | <span class="token keyword">const</span> club <span class="token operator">=</span> db <span class="token punctuation">.</span> <span class="token function">collection</span> <span class="token punctuation">(</span> <span class="token string">"clubs"</span> <span class="token punctuation">)</span> <span class="token punctuation">.</span> <span class="token function">doc</span> <span class="token punctuation">(</span> <span class="token string">'1'</span> <span class="token punctuation">)</span> <span class="token punctuation">.</span> <span class="token function">get</span> <span class="token punctuation">(</span> <span class="token punctuation">)</span> <span class="token punctuation">.</span> <span class="token function">data</span> <span class="token punctuation">(</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span> <span class="token keyword">const</span> league <span class="token operator">=</span> db <span class="token punctuation">.</span> <span class="token function">collection</span> <span class="token punctuation">(</span> <span class="token string">"leagues"</span> <span class="token punctuation">)</span> <span class="token punctuation">.</span> <span class="token function">doc</span> <span class="token punctuation">(</span> club <span class="token punctuation">.</span> league_id <span class="token punctuation">)</span> <span class="token punctuation">.</span> <span class="token function">get</span> <span class="token punctuation">(</span> <span class="token punctuation">)</span> <span class="token punctuation">.</span> <span class="token function">data</span> <span class="token punctuation">(</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span> |
However, if instead of saving league_id to save information of the league this club is playing, we will save that League’s refernce as leagueRef, then we only need 1 query to get the League that t need.
1 2 | <span class="token keyword">const</span> league <span class="token operator">=</span> db <span class="token punctuation">.</span> <span class="token function">collection</span> <span class="token punctuation">(</span> <span class="token string">"clubs"</span> <span class="token punctuation">)</span> <span class="token punctuation">.</span> <span class="token function">doc</span> <span class="token punctuation">(</span> <span class="token string">'1'</span> <span class="token punctuation">)</span> <span class="token punctuation">.</span> <span class="token function">get</span> <span class="token punctuation">(</span> <span class="token punctuation">)</span> <span class="token punctuation">.</span> <span class="token function">data</span> <span class="token punctuation">(</span> <span class="token punctuation">)</span> <span class="token punctuation">.</span> leagueRef <span class="token punctuation">.</span> <span class="token function">get</span> <span class="token punctuation">(</span> <span class="token punctuation">)</span> <span class="token punctuation">.</span> <span class="token function">data</span> <span class="token punctuation">(</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span> |
Simple and more explicit right.
To insert the reference data type is also very simple,
1 2 3 4 5 6 | <span class="token keyword">const</span> club <span class="token operator">=</span> <span class="token punctuation">{</span> name <span class="token operator">:</span> <span class="token string">"Chelsea"</span> <span class="token punctuation">,</span> leagueRef <span class="token operator">:</span> db <span class="token punctuation">.</span> <span class="token function">doc</span> <span class="token punctuation">(</span> <span class="token string">"league/1"</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span> <span class="token comment">// league_id của Premier League là `1`</span> <span class="token punctuation">}</span> |
Thank you for reading my short article, hope it helps! I wish you a happy working day.