diff --git a/awesome-go/sqlx/main.go b/awesome-go/sqlx/main.go new file mode 100644 index 0000000..4763af6 --- /dev/null +++ b/awesome-go/sqlx/main.go @@ -0,0 +1,141 @@ +package main + +import ( + "database/sql" + "fmt" + "log" + + "github.com/jmoiron/sqlx" + _ "github.com/lib/pq" +) + +var schema = ` +CREATE TABLE person ( + first_name text, + last_name text, + email text +); + +CREATE TABLE place ( + country text, + city text NULL, + telcode INTEGER +)` + +type Person struct { + FirstName string `db:"first_name"` + LastName string `db:"last_name"` + Email string +} + +type Place struct { + Country string + City sql.NullString + TelCode int +} + +func main() { + // this Pings the database trying to connect + // use sqlx.Open() for sql.Open() semantics + db, err := sqlx.Connect("postgres", "user=foo dbname=bar sslmode=disable") + if err != nil { + log.Fatalln(err) + } + + // exec the schema or fail; multi-statement Exec behavior varies between + // database drivers; pq will exec them all, sqlite3 won't, ymmv + db.MustExec(schema) + + tx := db.MustBegin() + tx.MustExec("INSERT INTO person (first_name, last_name, email) VALUES ($1, $2, $3)", "Jason", "Moiron", "jmoiron@jmoiron.net") + tx.MustExec("INSERT INTO person (first_name, last_name, email) VALUES ($1, $2, $3)", "John", "Doe", "johndoeDNE@gmail.net") + tx.MustExec("INSERT INTO place (country, city, telcode) VALUES ($1, $2, $3)", "United States", "New York", "1") + tx.MustExec("INSERT INTO place (country, telcode) VALUES ($1, $2)", "Hong Kong", "852") + tx.MustExec("INSERT INTO place (country, telcode) VALUES ($1, $2)", "Singapore", "65") + // Named queries can use structs, so if you have an existing struct (i.e. person := &Person{}) that you have populated, you can pass it in as &person + tx.NamedExec("INSERT INTO person (first_name, last_name, email) VALUES (:first_name, :last_name, :email)", &Person{"Jane", "Citizen", "jane.citzen@example.com"}) + tx.Commit() + + // Query the database, storing results in a []Person (wrapped in []interface{}) + people := []Person{} + db.Select(&people, "SELECT * FROM person ORDER BY first_name ASC") + jason, john := people[0], people[1] + + fmt.Printf("%#v", jason) + fmt.Printf("%#v", john) + // Person{FirstName:"Jason", LastName:"Moiron", Email:"jmoiron@jmoiron.net"} + // Person{FirstName:"John", LastName:"Doe", Email:"johndoeDNE@gmail.net"} + + // You can also get a single result, a la QueryRow + jason = Person{} + err = db.Get(&jason, "SELECT * FROM person WHERE first_name=$1", "Jason") + fmt.Printf("%#v\n", jason) + // Person{FirstName:"Jason", LastName:"Moiron", Email:"jmoiron@jmoiron.net"} + + // if you have null fields and use SELECT *, you must use sql.Null* in your struct + places := []Place{} + err = db.Select(&places, "SELECT * FROM place ORDER BY telcode ASC") + if err != nil { + fmt.Println(err) + return + } + usa, singsing, honkers := places[0], places[1], places[2] + + fmt.Printf("%#v\n%#v\n%#v\n", usa, singsing, honkers) + // Place{Country:"United States", City:sql.NullString{String:"New York", Valid:true}, TelCode:1} + // Place{Country:"Singapore", City:sql.NullString{String:"", Valid:false}, TelCode:65} + // Place{Country:"Hong Kong", City:sql.NullString{String:"", Valid:false}, TelCode:852} + + // Loop through rows using only one struct + place := Place{} + rows, err := db.Queryx("SELECT * FROM place") + for rows.Next() { + err := rows.StructScan(&place) + if err != nil { + log.Fatalln(err) + } + fmt.Printf("%#v\n", place) + } + // Place{Country:"United States", City:sql.NullString{String:"New York", Valid:true}, TelCode:1} + // Place{Country:"Hong Kong", City:sql.NullString{String:"", Valid:false}, TelCode:852} + // Place{Country:"Singapore", City:sql.NullString{String:"", Valid:false}, TelCode:65} + + // Named queries, using `:name` as the bindvar. Automatic bindvar support + // which takes into account the dbtype based on the driverName on sqlx.Open/Connect + _, err = db.NamedExec(`INSERT INTO person (first_name,last_name,email) VALUES (:first,:last,:email)`, + map[string]interface{}{ + "first": "Bin", + "last": "Smuth", + "email": "bensmith@allblacks.nz", + }) + + // Selects Mr. Smith from the database + rows, err = db.NamedQuery(`SELECT * FROM person WHERE first_name=:fn`, map[string]interface{}{"fn": "Bin"}) + + // Named queries can also use structs. Their bind names follow the same rules + // as the name -> db mapping, so struct fields are lowercased and the `db` tag + // is taken into consideration. + rows, err = db.NamedQuery(`SELECT * FROM person WHERE first_name=:first_name`, jason) + + // batch insert + + // batch insert with structs + personStructs := []Person{ + {FirstName: "Ardie", LastName: "Savea", Email: "asavea@ab.co.nz"}, + {FirstName: "Sonny Bill", LastName: "Williams", Email: "sbw@ab.co.nz"}, + {FirstName: "Ngani", LastName: "Laumape", Email: "nlaumape@ab.co.nz"}, + } + + _, err = db.NamedExec(`INSERT INTO person (first_name, last_name, email) + VALUES (:first_name, :last_name, :email)`, personStructs) + + // batch insert with maps + personMaps := []map[string]interface{}{ + {"first_name": "Ardie", "last_name": "Savea", "email": "asavea@ab.co.nz"}, + {"first_name": "Sonny Bill", "last_name": "Williams", "email": "sbw@ab.co.nz"}, + {"first_name": "Ngani", "last_name": "Laumape", "email": "nlaumape@ab.co.nz"}, + } + + _, err = db.NamedExec(`INSERT INTO person (first_name, last_name, email) + VALUES (:first_name, :last_name, :email)`, personMaps) +}