forked from mirror/gorm
60 lines
1.1 KiB
Markdown
60 lines
1.1 KiB
Markdown
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## Migration
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<!-- toc -->
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### Auto Migration
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Automatically migrate your schema, to keep your schema update to date
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**WARNING** AutoMigrate will ONLY create tables, columns and indexes if doesn't exist,
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WON'T change existing column's type or delete unused columns to protect your data
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```go
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db.AutoMigrate(&User{})
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db.AutoMigrate(&User{}, &Product{}, &Order{})
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// Add table suffix when create tables
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db.Set("gorm:table_options", "ENGINE=InnoDB").AutoMigrate(&User{})
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```
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### Has Table
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```go
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// Check if model `User`'s table has been created or not
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db.HasTable(&User{})
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// Check table `users` exists or not
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db.HasTable("users")
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```
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### Create Table
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```go
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db.CreateTable(&User{})
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db.Set("gorm:table_options", "ENGINE=InnoDB").CreateTable(&User{})
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// will append "ENGINE=InnoDB" to the SQL statement when creating table `users`
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```
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### Drop table
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```go
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db.DropTable(&User{})
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```
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### ModifyColumn
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Change column's type
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```go
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// change column description's data type to `text` for model `User`'s table
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db.Model(&User{}).ModifyColumn("description", "text")
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```
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### DropColumn
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```go
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db.Model(&User{}).DropColumn("description")
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```
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