Prep finds all SQL statements in a Go package and instruments db connection with prepared statements. It allows you to benefit from the prepared SQL statements almost without any changes to your code.
Prep consists of two parts:
- A command line tool that finds all SQL statements in your code
- A package that instruments your code with prepared SQL statements using the found ones
$ cat example.go
funcmain(){db, err:=sql.Open("mysql", "user:pass@tcp(localhost:3306)/mysql") iferr!=nil{panic(err) } constquery=`SELECT CONCAT("Hello ", ?, "!")`varsstringiferr:=db.QueryRow(query, "World").Scan(&s); err!=nil{panic(err) } fmt.Println(s) }Let's generate a list of the SQL statements used in your package:
$ prep -f github.com/hexdigest/prepdemo $ cat prepared_statements.go//go:generate prep -f github.com/hexdigest/prepdemopackage main varprepStatements= []string{"SELECT CONCAT(\"Hello \", ?, \"!\")", }funcmain(){sqlDB, err:=sql.Open("mysql", "root:root@tcp(localhost:3306)/mysql") iferr!=nil{panic(err) } db, err:=prep.NewConnection(sqlDB, prepStatements) iferr!=nil{panic(err) } constquery=`SELECT CONCAT("Hello ", ?, "!")`varsstringiferr:=db.QueryRow(query, "World").Scan(&s); err!=nil{panic(err) } fmt.Println(s) }Take a look at the line:
db, err:=prep.NewConnection(sqlDB, prepStatements)It instruments your connection with prepared statements found by the generator. The generated code already contains //go:generate instruction, so in order to update the statements list you can simply run:
$ go generate$ go test -bench=. BenchmarkPostgresWithoutPreparedStatements-4 20000 59941 ns/op 1183 B/op 32 allocs/op BenchmarkPostgresWithPreparedStatements-4 50000 41560 ns/op 1021 B/op 26 allocs/op BenchmarkMySQLWithoutPreparedStatements-4 50000 26454 ns/op 827 B/op 23 allocs/op BenchmarkMySQLWithPreparedStatements-4 200000 9509 ns/op 634 B/op 19 allocs/op PASS ok github.com/hexdigest/prep 7.884s