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fix(database/gdb): Resolve the cache error overwriting caused by the use of fixed cache keys in pagination queries.
func main() {
adapter := gcache.NewAdapterRedis(g.Redis())
g.DB().GetCache().SetAdapter(adapter)
result, count, err := g.Model("TBL_USER").Cache(gdb.CacheOption{
Duration: 100 * time.Minute,
Name: "VIP",
}).AllAndCount(false)
g.DumpJson(result)
fmt.Println(count, err)
}
执行这段查询后g.DumpJson(result)的结果是[ { "COUNT(1)": 5 } ],但是正确结果应该是五条用户信息,查看源代码后发现先执行的count查询和后来select查询都是直接使用了VIP这个缓存key,在redis中实际缓存key是SelectCache:VIP,第二步查询select获得的是count查询的缓存,所以查询结果是错的。 因此为Model增加一个PageCache方法允许用户分别设置count query和data query的缓存参数
// PageCache sets the cache feature for pagination queries. It allows to configure
// separate cache options for count query and data query in pagination.
//
// Note that, the cache feature is disabled if the model is performing select statement
// on a transaction.
func (m *Model) PageCache(countOption CacheOption, dataOption CacheOption) *Model {
model := m.getModel()
model.pageCacheOption = []CacheOption{countOption, dataOption}
model.cacheEnabled = true
return model
}
然后AllAndCount在查询时分别给两个查询设置对应的缓存参数ScanAndCount同理
// AllAndCount retrieves all records and the total count of records from the model.
// If useFieldForCount is true, it will use the fields specified in the model for counting;
// otherwise, it will use a constant value of 1 for counting.
// It returns the result as a slice of records, the total count of records, and an error if any.
// The where parameter is an optional list of conditions to use when retrieving records.
//
// Example:
//
// var model Model
// var result Result
// var count int
// where := []any{"name = ?", "John"}
// result, count, err := model.AllAndCount(true)
// if err != nil {
// // Handle error.
// }
// fmt.Println(result, count)
func (m *Model) AllAndCount(useFieldForCount bool) (result Result, totalCount int, err error) {
// Clone the model for counting
countModel := m.Clone()
// If useFieldForCount is false, set the fields to a constant value of 1 for counting
if !useFieldForCount {
countModel.fields = []any{Raw("1")}
}
if len(m.pageCacheOption) > 0 {
countModel = countModel.Cache(m.pageCacheOption[0])
}
// Get the total count of records
totalCount, err = countModel.Count()
if err != nil {
return
}
// If the total count is 0, there are no records to retrieve, so return early
if totalCount == 0 {
return
}
resultModel := m.Clone()
if len(m.pageCacheOption) > 1 {
resultModel = resultModel.Cache(m.pageCacheOption[1])
}
// Retrieve all records
result, err = resultModel.doGetAll(m.GetCtx(), SelectTypeDefault, false)
return
}