GitHub - hexdigest/prep: Prep finds all SQL statements in a Go package and instruments db connection with prepared statements (original) (raw)

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

Usage

Generate a list of SQL statements used in your application

$ cat example.go

func main() { db, err := sql.Open("mysql", "user:pass@tcp(localhost:3306)/mysql") if err != nil { panic(err) } const query = SELECT CONCAT("Hello ", ?, "!") var s string if err := 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/prepdemo

package main

var prepStatements = []string{ "SELECT CONCAT("Hello ", ?, "!")", }

Using prepared statements

func main() { sqlDB, err := sql.Open("mysql", "root:root@tcp(localhost:3306)/mysql") if err != nil { panic(err) }

db, err := prep.NewConnection(sqlDB, prepStatements)
if err != nil {
    panic(err)
}

const query = `SELECT CONCAT("Hello ", ?, "!")`
var s string
if err := 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:

Some synthetic benchmarks

$ 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