gh-ost/vendor/github.com/jmoiron/sqlx/bind.go
2016-06-16 11:28:42 +02:00

85 lines
1.8 KiB
Go

package sqlx
import (
"bytes"
"strconv"
)
// Bindvar types supported by Rebind, BindMap and BindStruct.
const (
UNKNOWN = iota
QUESTION
DOLLAR
NAMED
)
// BindType returns the bindtype for a given database given a drivername.
func BindType(driverName string) int {
switch driverName {
case "postgres", "pgx":
return DOLLAR
case "mysql":
return QUESTION
case "sqlite3":
return QUESTION
case "oci8":
return NAMED
}
return UNKNOWN
}
// FIXME: this should be able to be tolerant of escaped ?'s in queries without
// losing much speed, and should be to avoid confusion.
// FIXME: this is now produces the wrong results for oracle's NAMED bindtype
// Rebind a query from the default bindtype (QUESTION) to the target bindtype.
func Rebind(bindType int, query string) string {
if bindType != DOLLAR {
return query
}
qb := []byte(query)
// Add space enough for 10 params before we have to allocate
rqb := make([]byte, 0, len(qb)+10)
j := 1
for _, b := range qb {
if b == '?' {
rqb = append(rqb, '$')
for _, b := range strconv.Itoa(j) {
rqb = append(rqb, byte(b))
}
j++
} else {
rqb = append(rqb, b)
}
}
return string(rqb)
}
// Experimental implementation of Rebind which uses a bytes.Buffer. The code is
// much simpler and should be more resistant to odd unicode, but it is twice as
// slow. Kept here for benchmarking purposes and to possibly replace Rebind if
// problems arise with its somewhat naive handling of unicode.
func rebindBuff(bindType int, query string) string {
if bindType != DOLLAR {
return query
}
b := make([]byte, 0, len(query))
rqb := bytes.NewBuffer(b)
j := 1
for _, r := range query {
if r == '?' {
rqb.WriteRune('$')
rqb.WriteString(strconv.Itoa(j))
j++
} else {
rqb.WriteRune(r)
}
}
return rqb.String()
}