set _creationTime from created_at on migration from other database
hey all. What's the best way to instantiate/overwrite _creationTime? I am migrating data from postgres and need to change the _creationTime for documents to match up with the original created_at time(s)
7 Replies
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Thank you!
_creationTime is source of truth in convex, its immutable. should i suggest creating a new field when migrating to convex something like
originalCreatedAt and then adding an index on top in the table .index("by_originalCreatedAt", ["originalCreatedAt"]) will essentially work the same for querying as _creationTime.
just a suggestion to also add a field migratedAt so you can track migration date/time data seperately later if required.but this means I always have to maintain a secondary created_at field? I will not be able to remove this column
yeah you can't rewrite history
_creationTime but you can keep the past intact originalCreatedAtbut this also means the future is affected? I mean we cannot eventually move to comparing based of
_creationTime we will always have to insert a value for created_at and use created_at for the comparison. Is this expected design/behaviour for convex to ignore the system _creationTime?As I said before, creating an index makes your createdAt field just as efficient to query as the system's _creationTime. This means there is no performance overhead and it keeps your code consistent.
If you don't want to handle that yourself, there is another layer of customMutation and customQuery
ref:
https://www.npmjs.com/package/convex-helpers#row-level-security
e.g.
export const myMutation = customMutation(mutation, customCtx(async (ctx) => ({
db: {
...ctx.db,
insert: async (table, value) => {
// Always set createdAt automatically
return ctx.db.insert(table, { ...value, createdAt: Date.now() });
},
},
})));
now your time field logic is centralized. same for queries:
export const myQuery = customQuery(query, customCtx(async (ctx) => ({
db: {
...ctx.db,
queryByCreatedAt: (table) =>
ctx.db.query(table).withIndex("by_createdAt").order("desc"),
},
})));
and your business logic never needs to handle createdAt directly. you just use myQuery and myMutation instead of default mutation and query in convex functions.npm
convex-helpers
A collection of useful code to complement the official convex package.. Latest version: 0.1.95, last published: a day ago. Start using convex-helpers in your project by running
npm i convex-helpers. There are 16 other projects in the npm registry using convex-helpers.got it. Thank you so much for this reply. makes a lot of sense