࠷଎ͷΫΤϦϏϧμΛ ໝ૝ͯ͠Έͨ @mackee_w a.k.a Ϛίϐʔ ΠΧID: mackee_w

YAPCԠื͍ͯ͠·͢ • http://yapcasia.org/2015/talk/show/ a668ef3e-080b-11e5-b2b4-79c97d574c3a • Ͳ͏ͯ͠΋PerlͰυϩʔϯΛඈ͹͍ͨ͠ਓͷͨ Ίͷϋʔυ΢ΣΞϋοΫ֓࿦ • ·ͨͷ໊Λୁั͞Εͳ͍ͨΊʹυϩʔϯΛඈ ͹ͨ͢Ίͷ97ͷ͜ͱ

GoͷΫΤϦϏϧμ • lann/squirrel import sq “github.com/lann/squirrel” query, args, err := sq.Select(“id”, “name”).From(“user”).Where(sq.Eq{“id”: id}).ToSql() row := db.QueryRow(query, args…)

sq.Where(sq.Eq{“id”: id}) ↑͍ͭ͜͸ϦϑϨΫγϣϯ

ͦsquirrel͸ΫΤϦϏϧμ • ΫΤϦϏϧμͳͷͰεΩʔϚΛ஌Βͳ͍ • εΩʔϚΛ஌Βͳ͍ͷͰΧϥϜͷܕΛ஌Βͳ ͍ • ͱ͍͏͔interface{}ͳͷͰͳΜͰ΋ಥͬࠐΊΔ • errorͱ͔ಥͬࠐΊΔɺͦͯ͠panicΔ

ϦϑϨΫγϣϯͷޭࡑ • ϦϑϨΫγϣϯʹΑΓͱΓ͋͑ͣinterface{}Ͱ ड͚ͯͦͷޙͷ͜ͱ͸ޙͰߟ͑ΔΈ͍ͨͳ͜ ͱ͕ग़དྷΔ • ͦͷ୅ΘΓʹಈ͍͍ͯΔͱ͖ʹpanicΔͷͰਓ ͕͕ؒΜ͹ͬͯpanicΒͳ͍Α͏ʹಥͬࠐΉ΋ ͷΛ؂ࢹ͠ͳ͚Ε͹ͳΒͳ͍

ܕͱ͸Կͩͬͨͷ͔ (Go͸ܕϏονݴޠͱ͍͏੠ ͸͜͜Ͱແࢹ͓ͯ͘͠)

sqlla - a pre- generated structure query buillder - ͔࣍Β͸ໝ૝Ͱ͢

go generate • Go͸1.4͔Βgo generateͱ͍͏࢓૊Έ͕௥Ճ ͞Εͨ • //go:generate hogehoge • ͜ΕΛهड़ͨ͠ιʔε͕ଘࡏ͢Δͱ͜ΖͰgo generateͬͯίϚϯυΛଧͭͱhogehogeͬͯ ͍͏ͷ͕γΣϧͰ࣮ߦ͞ΕΔ

࢖༻ྫ • https://godoc.org/golang.org/x/tools/cmd/ stringer จࣈྻԽग़དྷΔఆ਺Λ࡞ΔͨΊͷ generater • ఆ਺ͷ্ʹίϝϯτͰΞϊςʔγϣϯΛ࡞Δ ͱ fmt.Stringerͱ͍͏interfaceΛ࣮૷ͨ͠type Λఆٛͯ͠จࣈྻԽग़དྷͯศར

argen • ੩తղੳϕʔεͷORM • //+ARͬͯstructʹॻ͘ͱ͍Ζ͍Ζ࣮૷ͯ͘͠ ΕΔ(?)

genddl • ੿࡞ͷDDLੜ੒ث • //+table: <ςʔϒϧ໊>ͬͯstructʹॻ͍ͯΧ ϥϜ໊ͱ͔ΛλάͰॻ͘ͱDDLΛੜ੒ͯ͘͠ ΕΔ

ಓ۩ • go/parser + go/ast • text/template

ࠓճໝ૝ͨ͠ͷ͸ • ੩తղੳϕʔεͷΫΤϦϏϧμ import ( “github.com/mackee/sugoiapp/schema/user” ) user.UserId{1}.Name{“name”}.ToSql()

த਎ //+table: user type User struct { Id uint64 `db:”id”` Name string `db:”name”` }

͔͜͜Βauto generated type Name struct { Name string Expr sqlla.Expr } func (c Name) ToSql() { return “name “ + c.Expr.ToSql() + “?” }

͋ͱϝιουνΣΠϯͱ͔ ͸͕Μ͹ͬͯࣗಈੜ੒ϫΠϫ Π ྗٕ͡Ό

ͱ͍͏ͷΛ1࣌ؒલʹࢥ͍ͭ ͍ͨͷͰɺͦͷ͏࣮ͪ૷͠ͱ ͜(͜Ε͕Φν)