Gorm How to clear conditions, that were added by method chaining to a DB Handle, from that DB Handle

Your Question

Hello, we are using Method Chaining, and while it is powerful, we want to avoid problems when developers forget to use New Session. Is there a way, given a DB Handle, we can clear out the conditions that were added previously?

We tried starting a new session from a DB that had method chaining to understand if the NewSession would clear out the conditional statements, but it didn't.

db, err := gorm.Open(sqlite.Open("test.db"), &gorm.Config{}) // db is a new initialized *gorm.DB, which falls under New Session Mode tx := db.Where("name = ?", "jinzhu") // Where("name = ?", "jinzhu") is the first method call, it creates a new Statement and adds conditions

tx.Where("age = ?", 18).Find(&users) // tx.Where("age = ?", 18) REUSES above Statement, and adds conditions to the Statement // Find(&users) is a finisher, it executes registered Query Callbacks, generates and runs the following SQL: // SELECT * FROM users WHERE name = 'jinzhu' AND age = 18

// NOW OVER HERE, given the db can we create a new session that doesn't have any of the conditions. Can we basically have a //pristine DB as if it was just opened, by calling some function?

The document you expected this should be explained

Expected answer

Comment From: a631807682

// db with empty statement
// db.clone is 1
db, err := gorm.Open(sqlite.Open("test.db"), &gorm.Config{})
// when db.clone is 1 
// tx(db1)  is new DB copy form db and now db.clone is 0
// tx(db1) with where clause
tx := db.Where("name = ?", "jinzhu")
// tx(db1) add other where clause
tx.Where("age = ?", 18)

So if you use chaining method and db.clone is 1, it will copy a new db from old with stmt. (like NewSession) Just var tx2 like tx2 := db.Where() it will return a new db with empty stmt what you need.