组件分享之后端组件——基于Golang实现的database/sql附加功能组件dbr

go get -u github.com/gocraft/dbr/v2

import "github.com/gocraft/dbr/v2"

// create a connection (e.g. "postgres", "mysql", or "sqlite3")
conn, _ := Open("postgres", "...", nil)
conn.SetMaxOpenConns(10)

// create a session for each business unit of execution (e.g. a web request or goworkers job)
sess := conn.NewSession(nil)

// create a tx from sessions
sess.Begin()

sess := mysqlSession
tx, err := sess.Begin()
if err != nil {
    return
}
defer tx.RollbackUnlessCommitted()

// do stuff...

tx.Commit()

// columns are mapped by tag then by field
type Suggestion struct {
    ID  int64       // id, will be autoloaded by last insert id
    Title   NullString  `db:"subject"`  // subjects are called titles now
    Url string      `db:"-"`    // ignored
    secret  string      // ignored
}

// By default gocraft/dbr converts CamelCase property names to snake_case column_names.
// You can override this with struct tags, just like with JSON tags.
// This is especially helpful while migrating from legacy systems.
var suggestions []Suggestion
sess := mysqlSession
sess.Select("*").From("suggestions").Load(&suggestions)

// database/sql uses prepared statements, which means each argument
// in an IN clause needs its own question mark.
// gocraft/dbr, on the other hand, handles interpolation itself
// so that you can easily use a single question mark paired with a
// dynamically sized slice.

sess := mysqlSession
ids := []int64{1, 2, 3, 4, 5}
sess.Select("*").From("suggestions").Where("id IN ?", ids)