英文:
Ent. how to remove a column?
问题
我在我的Go项目中已经有一个Ent模型。但是我需要从模型中删除一些列。当我更新我的模型时，它不起作用。运行迁移会导致运行时错误。如何在Ent ORM中删除现有模型的列？
英文:
I have already an Ent model in my go project. But I need to remove some columns from the model.
It not works when I update my model. Running migration results runtime error.
How can I remove a column from existing model in Ent. ORM?
答案1
得分: 1
您可以通过在迁移中设置WithDropIndex和WithDropColumn选项来简单地更改模型以删除某些字段，如下所示：
package main
import (
"context"
"log"
"<project>/ent"
"<project>/ent/migrate"
)
func main() {
client, err := ent.Open("mysql", "root:pass@tcp(localhost:3306)/test")
if err != nil {
log.Fatalf("failed connecting to mysql: %v", err)
}
defer client.Close()
ctx := context.Background()
// 运行迁移。
err = client.Schema.Create(
ctx,
migrate.WithDropIndex(true),
migrate.WithDropColumn(true),
)
if err != nil {
log.Fatalf("failed creating schema resources: %v", err)
}
}
更多信息请参见文档
英文:
You can change model simply to remove some fields and this will works if you set WithDropIndex and WithDropColumn options within migration as follow:
package main
import (
"context"
"log"
"<project>/ent"
"<project>/ent/migrate"
)
func main() {
client, err := ent.Open("mysql", "root:pass@tcp(localhost:3306)/test")
if err != nil {
log.Fatalf("failed connecting to mysql: %v", err)
}
defer client.Close()
ctx := context.Background()
// Run migration.
err = client.Schema.Create(
ctx,
migrate.WithDropIndex(true),
migrate.WithDropColumn(true),
)
if err != nil {
log.Fatalf("failed creating schema resources: %v", err)
}
}
For more information see documentation
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