Gorm bool field with default:true always stored as true, even when explicitly set to false in JSON

I'm encountering unexpected behavior with GORM (v1.30.1) when inserting a record that includes a boolean field with default:true. Even when I explicitly send "is_active": false in the request JSON, GORM still inserts it as true in the database.

my model type ProductCategory struct { gorm.Model Name stringjson:"name" gorm:"unique;not null"NameTr stringjson:"name_tr" gorm:"size:100"Description stringjson:"description" gorm:"type:text"Slug stringjson:"slug" gorm:"uniqueIndex;size:100;not null"SortOrder intjson:"sort_order" gorm:"default:0"IsActive booljson:"is_active" gorm:"default:true"}

`2025/07/30 10:28:11 main.go:419: Starting server on http://localhost:8070 ... 2025/07/30 10:28:14 misc.go:86: Key 'root' is object with 6 fields 2025/07/30 10:28:14 misc.go:64: Key 'slug' is string: altin1 2025/07/30 10:28:14 misc.go:77: Key 'sort_order' is float64: 1.000000 2025/07/30 10:28:14 misc.go:79: Key 'is_active' is bool: false 2025/07/30 10:28:14 misc.go:64: Key 'name' is string: Altın1 2025/07/30 10:28:14 misc.go:64: Key 'name_tr' is string: Altın1 2025/07/30 10:28:14 misc.go:64: Key 'description' is string: Altın ürün kategorisi 2025/07/30 10:28:14 category.go:97: Parsed category.IsActive : false

2025/07/30 10:28:14 /Users/adam/zerduz/kuyum-go/market/handlers/category.go:99 [4.334ms] [rows:1] INSERT INTO product_categories (created_at,updated_at,deleted_at,name,name_tr,description,slug,sort_order,is_active) VALUES ('2025-07-30 10:28:14.382','2025-07-30 10:28:14.382',NULL,'Altın1','Altın1','Altın ürün kategorisi','altin1',1,true)`

Environment:

GORM version: v1.30.1

Go version: go1.24.5

Database: (MySQL 8.4)

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Comment From: Fuzzyma

This is an issue I run into today. Using "default: true" on any boolean field pretty much makes it always true even when specifically setting it to false:

package main

import (
    "log"
    "syscall"

    "fmt"

    "gorm.io/driver/postgres"
    "gorm.io/gorm"
)

func main() {
    connectionString := "host=localhost user=postgres password=yourpassword dbname=treed port=5432 sslmode=disable TimeZone=Europe/Berlin"
    db, _ := gorm.Open(postgres.Open(connectionString), &gorm.Config{})

    type Tree struct {
        ID     uint    `json:"id"`
        Exists bool    `json:"exists" gorm:"default:true"`
        Height float64 `json:"height" gorm:"type:FLOAT"`
    }

    tree := Tree{
        Exists: false,
        Height: 10.0,
    }

    db.Create(&tree)

    var debugCount struct {
        ExistsTrue  int64 `json:"exists_true"`
        ExistsFalse int64 `json:"exists_false"`
    }

    db.Model(&Tree{}).Where("exists = ?", true).Count(&debugCount.ExistsTrue)
    db.Model(&Tree{}).Where("exists = ?", false).Count(&debugCount.ExistsFalse)

    fmt.Printf("DEBUG: After insert - has %d trees with exists=true, %d with exists=false\n",
        debugCount.ExistsTrue, debugCount.ExistsFalse)
}