Created
March 20, 2021 10:25
-
-
Save turgayozgur/e8e7f3568d5ded9fbad0aeadf2ac4ab5 to your computer and use it in GitHub Desktop.
golang, scan nullable sql columns
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
func Scan(rows *sql.Rows, dest ...interface{}) error { | |
proxy := make([]interface{}, len(dest)) | |
for k, v := range dest { | |
switch v.(type) { | |
case *string: | |
proxy[k] = &sql.NullString{String: "", Valid: true} | |
case *bool: | |
proxy[k] = &sql.NullBool{Bool: false, Valid: true} | |
case *int: | |
proxy[k] = &sql.NullInt32{Int32: 0, Valid: true} | |
case *int32: | |
proxy[k] = &sql.NullInt32{Int32: 0, Valid: true} | |
case *int64: | |
proxy[k] = &sql.NullInt64{Int64: 0, Valid: true} | |
case *float32: | |
return errors.New("unable to map float32. use float64 instead") | |
case *float64: | |
proxy[k] = &sql.NullFloat64{Float64: 0, Valid: true} | |
case *time.Time: | |
proxy[k] = &sql.NullTime{Time: time.Time{}, Valid: true} | |
default: | |
return errors.New("unable to map. unknown field type") | |
} | |
} | |
if err := rows.Scan(proxy...); err != nil { | |
return err | |
} | |
for k, v := range dest { | |
switch d := v.(type) { | |
case *string: | |
*d = (proxy[k].(*sql.NullString)).String | |
case *bool: | |
*d = (proxy[k].(*sql.NullBool)).Bool | |
case *int: | |
*d = int((proxy[k].(*sql.NullInt32)).Int32) | |
case *int32: | |
*d = (proxy[k].(*sql.NullInt32)).Int32 | |
case *int64: | |
*d = (proxy[k].(*sql.NullInt64)).Int64 | |
case *float64: | |
*d = (proxy[k].(*sql.NullFloat64)).Float64 | |
case *time.Time: | |
*d = (proxy[k].(*sql.NullTime)).Time | |
} | |
} | |
return nil | |
} |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment