Perform regular Gorm tasks - in bulk!
This project aims to support the missing feature from the famous ORM Gorm. The feature I'm talking about is bulk support which has been on the wish list since 2014; see here.
This is inspired by t-tiger/gorm-bulk-insert which in turn is inspired by this comment but with the focus on flexibility and letting the end user handle final SQL, final values, how many to bulk at once etcetera.
This project is in it's early phase and since I want to ensure that the end user interface ends up as smoot, simple and flexible as possible I won't create a v1.0 release tag until I feel the most important things are in to place.
This doesn't mean that things aren't workign as indented, just that the API might change without notice.
go get -u github.com/bombsimon/gorm-bulk/...
To be able to iterate over any type you have to pass an interface slice
([]interface{}
). To make this easier this package is bundled with a code
generator that will generate functions to convert []*<T>
and []<T>
to
[]interface{}
.
See exmaples for details about how to use go generate
and what the
result will look like.
This package ships with a few standard bulk action methods. A bulk action uses
an ExecFunc
which takes a *gorm.Scope
(holding the table name, all the
values and where you may set the SQL), a slice of all column names and a slice
of all placeholder groups (a set of prepared statements for each slice element).
InsertFunc
- RegularINSERT INTO
with all passed values.InsertIgnoreFunc
- RunINSERT IGNORE INTO
with all passed values which will just discard duplicates (and any other error).InsertOnDuplicateKeyUpdateFunc
- RunINSERT INTO ... VALUES(...) ON DUPLICATE KEY UPDATE x = VALUES(x)
.
Notice that InsertFunc
and InsertIgnoreFunc
will look at
gorm:insert_option
to fetch any user defined additions.
These three ExecFunc
s are wrapped in BulkInsert
, BulkInsertIgnore
and
BulkInsertOnDuplicateKeyUpdate
so you only have to pass your *gorm.DB
and
interface slice.
func Example(db *gorm.DB, myTypes []MyType) error {
myTypesAsInterface := MyTypeSliceToInterfaceSlice(myTypes)
if err := gormbulk.BulkInsert(db, myTypesAsInterface); err != nil {
return err
}
return nil
}
To create your own action where you may return whatever SQL and values you want just implement an ExecFunc
. This is how a simple INSERT INTO
would be defined.
func MyCustomBulkFunc(scope *gorm.Scope, columnNames, placeholders []string) {
scope.Raw(fmt.Sprintf(
"INSERT INTO %s (%s) VALUES %s",
scope.QuotedTableName(),
strings.Join(columnNames, ", "),
strings.Join(placeholders, ", "),
))
}
If you just want to perform a simple bulk insert, use one of the pre implemented
wrapper bulk functions and pass your *gorm.DB
and data set, see the
example.