Bulk Insert

When adding a lot of data into your database using a bulk insert can save a lot of time. This has to do with the way databases work, and is true at the database level.

There are many different ways to “Bulk Insert” into a database, Welds tries to provide a common interface for the best option for each of its backends.

bulk_insert(_,_)

The bulk_insert function is that common interface. It is pretty strait forward taking in a Client and a slice of WeldsModels

bulk_insert is not accessible via the query builder like other operations. You will need to include it with:

#![allow(unused)]
fn main() {
    use welds::query::insert::bulk_insert;
}

First build a slice of data that you want to insert.

#![allow(unused)]
fn main() {
#[derive(WeldsModel)]
#[welds(table = "products")]
pub struct Product {
    #[welds(primary_key)]
    pub id: i32,
    pub name: String,
}
}

#![allow(unused)]
fn main() {
    let mut products: Vec<Product> = Vec::default();
    for i in (0..1000) {
        products.push( Product {
            id: 0,
            name: format!("product #{}", i)
        });
    }
}

Things to notice:

1. The column id is marked as a primary_key. Typically in welds if the primary_key field is Default::default() it is ignored when inserting. Here in Bulk insert the primary_key is ALWAYS ignored. If you want to insert a primary_key column, you can use the method: welds::query::insert::bulk_insert_with_ids
2. DbState is not used with bulk operations

You can now insert your data with a call to bulk_insert

#![allow(unused)]
fn main() {
    use welds::query::insert::bulk_insert;
    bulk_insert(&client, &products).await?;
}

Bulk Insert - Advanced Options

There are a couple extra, options for inserting into databases. They allow for overriding of the tablename. These can be extremely useful when importing data or using a temp table. They don’t contain “rust unsafe” code, but are labeled as unsafe because they to NOT protect from SQL injection. It goes without saying, don’t expose the tablename to a user.

bulk_insert_override_tablename_unsafe and bulk_insert_with_ids_override_tablename_unsafe

These two function work just like there safe counterparts, but allow manual setting of the tablename.