Supabase Quick Docs

I keep a small note when learning a new tool.

Not a full guide. Not polished documentation.

Just the syntax I actually use.

After a few projects with Supabase, I noticed the same pattern. I kept opening the docs, searching for the same things:

• How to insert a row
• How to query data
• How to update something
• How to call an RPC

So I wrote a small “quick syntax sheet”.

This is the version I wish I had when starting.

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Supabase is simple once you learn the core pattern.

Almost everything follows this shape:

supabase
  .from("table")
  .operation(...)

If you remember that, the rest becomes predictable.

Setup

Create a client first.

import { createClient } from "@supabase/supabase-js"

const supabase = createClient(
  process.env.NEXT_PUBLIC_SUPABASE_URL,
  process.env.NEXT_PUBLIC_SUPABASE_ANON_KEY
)

That’s it.

Now every database call starts with supabase.

Select (Read Data)

The most common query.

const { data, error } = await supabase
  .from("posts")
  .select("*")

You’ll probably write this line hundreds of times.

Select specific columns

.select("id, title, created_at")

Example:

const { data } = await supabase
  .from("posts")
  .select("id, title")

Filter rows

.eq(column, value)

Example:

const { data } = await supabase
  .from("posts")
  .select("*")
  .eq("author_id", user.id)

Other common filters:

.eq()   equal
.neq()  not equal
.gt()   greater than
.lt()   less than
.like() pattern match

Get one row

.single()

Example:

const { data } = await supabase
  .from("posts")
  .select("*")
  .eq("id", postId)
  .single()

Insert (Create Data)

Insert is straightforward.

const { data, error } = await supabase
  .from("posts")
  .insert({
    title: "\"My post\","
    content: "Hello world"
  })

Multiple rows:

.insert([
  { title: "\"Post 1\" },"
  { title: "\"Post 2\" }"
])

Return inserted data

Add .select().

const { data } = await supabase
  .from("posts")
  .insert({ title: "\"Hello\" })"
  .select()

Useful when you need the new id.

Update

Update rows with a filter.

const { data, error } = await supabase
  .from("posts")
  .update({ title: "\"Updated title\" })"
  .eq("id", postId)

Without a filter, it updates every row.

That’s a mistake most people make once.

Delete

Delete also requires a filter.

await supabase
  .from("posts")
  .delete()
  .eq("id", postId)

Again, no filter means deleting everything.

Ordering

Sort results.

.order("created_at", { ascending: false })

Example:

const { data } = await supabase
  .from("posts")
  .select("*")
  .order("created_at", { ascending: false })

Limit

Limit rows returned.

.limit(10)

Example:

const { data } = await supabase
  .from("posts")
  .select("*")
  .limit(10)

Pagination

Use .range().

.range(0, 9)

Example:

const { data } = await supabase
  .from("posts")
  .select("*")
  .range(0, 9)

This returns rows 0–9.

Joins

Supabase uses PostgREST syntax.

Example:

const { data } = await supabase
  .from("posts")
  .select("*, profiles(username)")

This joins the profiles table.

Example result:

post
  └ profile.username

Auth (Quick Syntax)

Get the current user:

const { data } = await supabase.auth.getUser()

Sign in:

await supabase.auth.signInWithPassword({
  email,
  password
})

Sign up:

await supabase.auth.signUp({
  email,
  password
})

Sign out:

await supabase.auth.signOut()

Storage

Upload a file.

await supabase.storage
  .from("avatars")
  .upload("user.png", file)

Get public URL:

supabase.storage
  .from("avatars")
  .getPublicUrl("user.png")

RPC (Calling Database Functions)

If you define a Postgres function, call it like this:

const { data } = await supabase
  .rpc("get_popular_posts")

With parameters:

.rpc("get_posts_by_user", {
  user_id: userId
})

The Pattern Behind Everything

After using Supabase for a while, you notice something simple.

Almost every query follows the same structure.

supabase
  .from(table)
  .action()
  .filter()
  .modifier()

Examples:

.from().select()
.from().insert()
.from().update()
.from().delete()

Once that clicks, the API feels predictable.

What I Actually Remember

When working quickly, I don’t remember the whole API.

I remember a few patterns:

• .from("table")
• .select("*")
• .insert({})
• .update({}).eq()
• .delete().eq()
• .order()
• .limit()

Everything else can be looked up.

A Small Lesson About Tools

Most tools feel complex at first.

But good tools have a small core idea.

For Supabase, it’s this:

Pick a table.
Choose an operation.
Add filters.

That’s most of the API.

Once you see the pattern, the documentation becomes easier to navigate.

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Read on my site: https://kimkorngmao.com/notes/supabase-quick-docs