Gorm gorm 分组查询文档描述用法的问题

Your Question

//这是官网对分组查询的描述 https://gorm.io/docs/advanced_query.html#Group-Conditions

db.Where(  db.Where("pizza = ?", "pepperoni").Where(db.Where("size = ?", "small").Or("size = ?", "medium")),).Or(  db.Where("pizza = ?", "hawaiian").Where("size = ?", "xlarge"),).Find(&Pizza{}).Statement

// SELECT * FROM `pizzas` WHERE (pizza = "pepperoni" AND (size = "small" OR size = "medium")) OR (pizza = "hawaiian" AND size = "xlarge")

但实际上不是这样的 我测试后的结果是

//实际结果
SELECT
    * 
FROM
    `test_models` 
WHERE
    pizza = 'pepperoni' 
    AND size = 'small' 
    OR size = 'medium' 
    AND ( pizza = 'pepperoni' AND size = 'small' OR size = 'medium' ) 
    AND (
        pizza = 'pepperoni' 
        AND size = 'small' 
        OR size = 'medium' 
    AND ( pizza = 'pepperoni' AND size = 'small' OR size = 'medium' )) 
    AND pizza = 'hawaiian' 
    AND size = 'xlarge' 
    OR (
        pizza = 'pepperoni' 
        AND size = 'small' 
        OR size = 'medium' 
        AND ( pizza = 'pepperoni' AND size = 'small' OR size = 'medium' ) 
        AND (
            pizza = 'pepperoni' 
            AND size = 'small' 
            OR size = 'medium' 
        AND ( pizza = 'pepperoni' AND size = 'small' OR size = 'medium' )) 
    AND pizza = 'hawaiian' 
    AND size = 'xlarge')

//正确的写法

db.Where(
            db.Session(&gorm.Session{NewDB: true}).Unscoped().Where("pizza = ?", "pepperoni").Where(db.Where("size = ?", "small").Or("size = ?", "medium")),
        ).Or(
            db.Session(&gorm.Session{NewDB: true}).Unscoped().Where("pizza = ?", "hawaiian").Where("size = ?", "xlarge"),
        ).Find(&pizza)

The document you expected this should be explained

Expected answer

Comment From: a631807682

Most of the documents do not describe what db is, but the default db refers to a shareable db instance, which can be created through gorm.Open or created through .Session

After a Chain method, Finisher Method, GORM returns an initialized *gorm.DB instance, which is NOT safe to reuse anymore, or new generated SQL might be polluted by the previous conditions, for example:

https://gorm.io/docs/method_chaining.html#content-inner