Default field value

Is there any way to specify default value for a document field (column)

3 Replies

Heath•5mo ago

Convex Ents have a mechanism for this. But afaik in the vanilla convex there isn’t. They have some documentation talking about reasons why, I think close to the docs regarding migrations. https://labs.convex.dev/convex-ents/schema#field-defaults

Ent Schema - Convex Ents

Relations, default values, unique fields and more for Convex

erquhart•5mo ago

Welcome! The default answer to most "how do you do X in Convex" is to just code it yourself. The fact that Convex enables this is itself a feature. More and more things will be enabled through packaged solutions, some of which will be "first party", but those too will just be Typescript that a user could write themselves. For default field values, the approach is the same as any default value in JS/TS. Here's an example where a table of posts has a required featured field, and false is provided as the default value in the mutation:

const posts = defineTable({
  authorId: v.id('users'),
  content: v.string(),
  featured: v.boolean(),
})

const insertPost = mutation({
  args: {
    authorId: v.id('users'),
    content: v.string(),
    featured: v.optional(v.boolean()),
  },
  handler: async (ctx, args) => {
    const post = {
      authorId: args.authorId,
      content: args.content,
      featured: args.featured ?? false,
    }
    await ctx.db.insert('posts', post)
  },
})

const posts = defineTable({
  authorId: v.id('users'),
  content: v.string(),
  featured: v.boolean(),
})

const insertPost = mutation({
  args: {
    authorId: v.id('users'),
    content: v.string(),
    featured: v.optional(v.boolean()),
  },
  handler: async (ctx, args) => {
    const post = {
      authorId: args.authorId,
      content: args.content,
      featured: args.featured ?? false,
    }
    await ctx.db.insert('posts', post)
  },
})

DeepakDahiyaOP•4mo ago

I see,

"The default answer to most 'how do you do X in Convex' is to just code it yourself."

Well this, surely helps in building the mental model while using convex. Thanks man!

Default field value

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