import (
"github.com/alifiroozi80/duckdb"
"gorm.io/gorm"
)
// DO NOT use 'gorm.Model' here. See 'Limitations' for more.
type Product struct {
ID uint `gorm:"primarykey"`
Code string
Price uint
CreatedAt time.Time
UpdatedAt time.Time
}
func main() {
// duckdb extentions: .ddb, .duckdb, .db
db, err := gorm.Open(duckdb.Open("duckdb.ddb"), &gorm.Config{})
if err != nil {
panic("failed to connect database")
}
// Migrate the schema
db.AutoMigrate(&Product{})
// Create
db.Create(&Product{Code: "D42", Price: 100})
// Read
var product Product
db.First(&product, 1) // find product with integer primary key
db.First(&product, "code = ?", "D42") // find product with code D42
// Update - update product's price to 200
db.Model(&product).Update("Price", 200)
// Update - update multiple fields
db.Model(&product).Updates(Product{Price: 200, Code: "F42"}) // non-zero fields
db.Model(&product).Updates(map[string]interface{}{"Price": 200, "Code": "F42"})
// Delete - delete product
db.Delete(&product, 1)
}
Checkout https://gorm.io for details.
DuckDB has two index types:
- Min-Max (Zonemap)
- Adaptive Radix Tree
In DuckDB, ART indexes are automatically created for columns with a
UNIQUE
orPRIMARY KEY
constraint and can be defined usingCREATE INDEX
.
However, every technology has its pros and cons. Despite being helpful (read attached pdf), ART indexes have some limitations.
ART indexes create a secondary copy of the data in a second location – this complicates processing, particularly when combined with transactions. Certain limitations apply when it comes to modifying data stored in secondary indexes.
Due to the presence of transactions, data can only be removed from the index after the transaction that performed the delete is committed and no further transactions that refer to the old entry are still present in the index. As a result, transactions that perform deletions followed by insertions may trigger unexpected, unique constraint violations, as the deleted tuple has not yet been removed from the index. For example:
GORM will update the deleted_at
column when you perform a db.Delete()
. so your db.Delete()
will be translate to:
UPDATE products SET deleted_at='2024-11-01 12:06:00.942' WHERE products.id = 1 AND products.deleted_at IS NULL;
And it cause an error:
Constraint Error: Duplicate key "id: 1" violates primary key constraint. If this is an unexpected constraint violation please double check with the known index limitations section in our documentation (https://duckdb.org/docs/sql/indexes).
That is why you should not use the default gorm.Model
structure and manually use ID
, CreatedAt
and UpdatedAt
.
For more info, see DuckDB documentations.
Any contributions you make are greatly appreciated.
See here for more details on contributing.
- Support switch indexes between ART and Min-Max in the configuraion.
- Implement TODO functions:
- ColumnTypes
- CreateConstraint
The license is under the MIT License. See LICENSE for more information.
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