Compare · 007

Enums as generated Go types, and your own types with go_type: ClickHouse and MySQL

Every file of the ClickHouse and MySQL versions side by side, with the lines that differ marked.

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Configuration

sgl.yamldiffers
ClickHouse
MySQL
1version: 1
1version: 1
2
2
3databases:
3databases:
4 - name: harbour
4 - name: menu
5 dialect: clickhouse
5 dialect: mysql
6 migrations: db/migrations
6 migrations: db/migrations
7 queries: db/queries
7 queries: db/queries
8 go:
8 go:
9 package: store
9 package: store
10 out: internal/store
10 out: internal/store
11 types:
12 overrides:
13 - column: menu_items.status
14 go: seagull.sh/seagull/examples/mysql/007_enums/internal/menu.Status

Migrations

db/migrations/0001_boats.up.sqldiffers
ClickHouse
MySQL · db/migrations/0001_menu.up.sql
1CREATE TABLE boats (
1CREATE TABLE menu_items (
2 id UInt64,
2 id BIGINT NOT NULL AUTO_INCREMENT PRIMARY KEY,
3 name String,
3 name VARCHAR(50) NOT NULL UNIQUE,
4 status Enum8('moored' = 1, 'fishing' = 2, 'in_dock' = 3)
4 section ENUM('fish', 'sides', 'puddings') NOT NULL,
5) ENGINE = MergeTree() ORDER BY id;
5 status ENUM('available', 'sold_out') NOT NULL DEFAULT 'available'
6);
db/migrations/0001_boats.down.sqldiffers
ClickHouse
MySQL · db/migrations/0001_menu.down.sql
1DROP TABLE boats;
1DROP TABLE menu_items;

Queries

AddBoatonly ClickHouse
ClickHouse · db/queries/boats.sql
MySQL · not in this version
1-- sgl.query(AddBoat, exec)
2INSERT INTO boats (id, name, status) VALUES ({id:UInt64}, {name:String}, {status:String});
ListBoatsonly ClickHouse
ClickHouse · db/queries/boats.sql
MySQL · not in this version
1-- sgl.query(ListBoats, many)
2SELECT id, name, status FROM boats ORDER BY id;
BoatsNotInonly ClickHouse
ClickHouse · db/queries/boats.sql
MySQL · not in this version
1-- sgl.query(BoatsNotIn, many)
2-- sgl.column(status, go_type: "seagull.sh/seagull/examples/clickhouse/007_enums/internal/domain.Status")
3SELECT id, name, status FROM boats WHERE status != {status:String} ORDER BY id;
AddItemonly MySQL
ClickHouse · not in this version
MySQL · db/queries/menu.sql
1-- sgl.query(AddItem, exec)
2INSERT INTO menu_items (name, section) VALUES (?, ?);
SetStatusonly MySQL
ClickHouse · not in this version
MySQL · db/queries/menu.sql
1-- sgl.query(SetStatus, execrows)
2UPDATE menu_items SET status = ? WHERE name = ?;
ListMenuonly MySQL
ClickHouse · not in this version
MySQL · db/queries/menu.sql
1-- sgl.query(ListMenu, many)
2SELECT name, section, status FROM menu_items ORDER BY section, name;
ItemsInSectiononly MySQL
ClickHouse · not in this version
MySQL · db/queries/menu.sql
1-- sgl.query(ItemsInSection, many)
2-- sgl.column(section, go_type: "seagull.sh/seagull/examples/mysql/007_enums/internal/menu.Section")
3SELECT name, section, status FROM menu_items WHERE section = ? ORDER BY name;

What sgl generates

AddBoatonly ClickHouse
ClickHouse
MySQL · not in this version
1func (queries *Queries) AddBoat(ctx context.Context, params AddBoatParams) error
2
3type AddBoatParams struct {
4 ID uint64
5 Name string
6 Status string
7}
ListBoatsonly ClickHouse
ClickHouse
MySQL · not in this version
1func (queries *Queries) ListBoats(ctx context.Context) ([]ListBoatsRow, error)
2
3type ListBoatsRow struct {
4 ID uint64 `json:"id"`
5 Name string `json:"name"`
6 Status BoatsStatus `json:"status"`
7}
8
9type BoatsStatus string
BoatsNotInonly ClickHouse
ClickHouse
MySQL · not in this version
1func (queries *Queries) BoatsNotIn(ctx context.Context, status string) ([]BoatsNotInRow, error)
2
3type BoatsNotInRow struct {
4 ID uint64 `json:"id"`
5 Name string `json:"name"`
6 Status domain.Status `json:"status"`
7}
AddItemonly MySQL
ClickHouse · not in this version
MySQL
1func (queries *Queries) AddItem(ctx context.Context, params AddItemParams) error
2
3type AddItemParams struct {
4 Name string
5 Section MenuItemsSection
6}
7
8type MenuItemsSection string
SetStatusonly MySQL
ClickHouse · not in this version
MySQL
1func (queries *Queries) SetStatus(ctx context.Context, params SetStatusParams) (int64, error)
2
3type SetStatusParams struct {
4 Status menu.Status
5 Name string
6}
ListMenuonly MySQL
ClickHouse · not in this version
MySQL
1func (queries *Queries) ListMenu(ctx context.Context) ([]ListMenuRow, error)
2
3type ListMenuRow struct {
4 Name string `json:"name"`
5 Section MenuItemsSection `json:"section"`
6 Status menu.Status `json:"status"`
7}
8
9type MenuItemsSection string
ItemsInSectiononly MySQL
ClickHouse · not in this version
MySQL
1func (queries *Queries) ItemsInSection(ctx context.Context, section MenuItemsSection) ([]ItemsInSectionRow, error)
2
3type MenuItemsSection string
4
5type ItemsInSectionRow struct {
6 Name string `json:"name"`
7 Section menu.Section `json:"section"`
8 Status menu.Status `json:"status"`
9}

The program

example.godiffers
ClickHouse
MySQL
1package main
1package main
2
2
3import (
3import (
4 "context"
4 "context"
5 "database/sql"
5 "database/sql"
6 "errors"
6 "fmt"
7 "fmt"
7 "io"
8 "io"
8 "strings"
9
9
10 "seagull.sh/seagull/examples/clickhouse/007_enums/internal/domain"
10 "seagull.sh/seagull/examples/mysql/007_enums/internal/menu"
11 "seagull.sh/seagull/examples/clickhouse/007_enums/internal/store"
11 "seagull.sh/seagull/examples/mysql/007_enums/internal/store"
12)
12)
13
13
14// run berths four boats and lists them twice. boats.status is an Enum8, and Seagull
14// run fills a chip shop menu whose section and status columns are MySQL ENUMs, marks an
15// declares a named Go type for it in models.go, named after the table and column that
15// item sold out and reads the menu back. Each ENUM becomes a named Go type in the
16// hold it: store.BoatsStatus, with a constant for each label, such as
16// generated package unless an override names a type of your own:
17// store.BoatsStatusMoored, and a Valid method. ListBoats returns Status as a
18// store.BoatsStatus. The status parameters are written {status:String}, so they are plain
19// strings, and the server converts the label to the Enum8.
20//
17//
21// BoatsNotIn adds sgl.column(status, go_type: "…/internal/domain.Status"), so its rows
18// - section has no override, so models.go declares store.MenuItemsSection, named after
22// carry the harbour's own domain.Status type, with its constants and methods. The
19// the table and column that hold the ENUM, with a constant for each value, such as
23// override changes only that query's result rows: parameters stay string, so the example
20// store.MenuItemsSectionFish, and a Valid method; ListMenuRow.Section,
24// converts with string(domain.StatusInDock) on the way in. A types.overrides entry in
21// AddItemParams.Section and ItemsInSection's parameter are all a
25// sgl.yaml would change every query's rows the same way.
22// store.MenuItemsSection;
23// - sgl.yaml's types.overrides names the column menu_items.status, so every query that
24// returns it as it is gives menu.Status, as in ListMenuRow.Status, and so does every
25// parameter compared with or assigned to it, as in SetStatusParams.Status; models.go
26// uses it too, and the generated package declares no type for that ENUM;
27// - sgl.column(section, go_type: ...) in ItemsInSection gives that one query's returned
28// Section the type menu.Section; the parameter it compares with stays a
29// store.MenuItemsSection.
26//
30//
27// ClickHouse checks every label against the Enum8, so a status that is not one of its
31// An ENUM sorts in the order its values are declared, not alphabetically, so ORDER BY
28// labels is refused by the server, not stored.
32// section lists fish, then sides, then puddings. Valid reports whether a value is one the
33// ENUM declares, so the shop can check a section before it binds it. In strict mode, the
34// default since MySQL 5.7, a value the ENUM does not list is refused as it is stored as
35// well; MySQL keeps an ENUM as the index of its value, and its error says the value was
36// truncated.
29//
37//
30// Takes database (*sql.DB) which is a migrated database.
38// Takes database (*sql.DB) which is a migrated database.
31// Takes output (io.Writer) which receives both listings and the refusal.
39// Takes output (io.Writer) which receives the menu, the fish section and the refusal.
32//
40//
33// Returns error when a query fails or a bad status is accepted.
41// Returns error when a query fails other than as the example expects.
34func run(ctx context.Context, database *sql.DB, output io.Writer) error {
42func run(ctx context.Context, database *sql.DB, output io.Writer) error {
35 queries := store.New(database)
43 queries := store.New(database)
36
44
37 boats := []store.AddBoatParams{
45 items := []store.AddItemParams{
38 {ID: 1, Name: "Kittiwake", Status: string(domain.StatusMoored)},
46 {Name: "cod", Section: store.MenuItemsSectionFish},
39 {ID: 2, Name: "Salty Chip", Status: string(domain.StatusFishing)},
47 {Name: "haddock", Section: store.MenuItemsSectionFish},
40 {ID: 3, Name: "Gull Wing", Status: string(domain.StatusInDock)},
48 {Name: "chips", Section: store.MenuItemsSectionSides},
41 {ID: 4, Name: "Driftwood", Status: string(domain.StatusFishing)},
49 {Name: "mushy peas", Section: store.MenuItemsSectionSides},
50 {Name: "sticky toffee pudding", Section: store.MenuItemsSectionPuddings},
42 }
51 }
43 for _, boat := range boats {
52 for _, item := range items {
44 if err := queries.AddBoat(ctx, boat); err != nil {
53 if err := queries.AddItem(ctx, item); err != nil {
45 return fmt.Errorf("adding %s: %w", boat.Name, err)
54 return fmt.Errorf("adding %s: %w", item.Name, err)
46 }
55 }
47 }
56 }
57 if _, err := queries.SetStatus(ctx, store.SetStatusParams{Status: menu.SoldOut, Name: "haddock"}); err != nil {
58 return fmt.Errorf("selling out of haddock: %w", err)
59 }
48
60
49 listed, err := queries.ListBoats(ctx)
61 listed, err := queries.ListMenu(ctx)
50 if err != nil {
62 if err != nil {
51 return fmt.Errorf("listing boats: %w", err)
63 return fmt.Errorf("listing the menu: %w", err)
52 }
64 }
53 fmt.Fprintln(output, "all boats, status as store.BoatsStatus:")
65 var menuRow store.ListMenuRow
54 for _, boat := range listed {
66 fmt.Fprintf(output, "ListMenu: section %T, status %T\n", menuRow.Section, menuRow.Status)
55 fmt.Fprintf(output, " %d %-11s %s\n", boat.ID, boat.Name, boat.Status)
67 for _, item := range listed {
68 fmt.Fprintf(output, " %-9s %s%s\n", item.Section, item.Name, soldOut(item.Status))
56 }
69 }
57
70
58 afloat, err := queries.BoatsNotIn(ctx, string(domain.StatusInDock))
71 fish, err := queries.ItemsInSection(ctx, store.MenuItemsSectionFish)
59 if err != nil {
72 if err != nil {
60 return fmt.Errorf("listing boats not in dock: %w", err)
73 return fmt.Errorf("listing the fish: %w", err)
61 }
74 }
62 fmt.Fprintln(output, "not in dock, status as domain.Status:")
75 var sectionRow store.ItemsInSectionRow
63 for _, boat := range afloat {
76 fmt.Fprintf(output, "ItemsInSection: section %T, status %T\n", sectionRow.Section, sectionRow.Status)
64 fmt.Fprintf(output, " %d %-11s %-8s at sea: %t\n", boat.ID, boat.Name, boat.Status, boat.Status.AtSea())
77 for _, item := range fish {
78 fmt.Fprintf(output, " %-9s %s%s\n", item.Section, item.Name, soldOut(item.Status))
65 }
79 }
66
80
67 sunk := store.AddBoatParams{ID: 5, Name: "Old Barnacle", Status: "sunk"}
81 drinks := store.MenuItemsSection("drinks")
68 err = queries.AddBoat(ctx, sunk)
82 fmt.Fprintf(output, "section drinks is valid: %t\n", drinks.Valid())
83 err = queries.AddItem(ctx, store.AddItemParams{Name: "lemonade", Section: drinks})
69 if err == nil {
84 if err == nil {
70 return fmt.Errorf("adding status %q: got no error, want the server's refusal", sunk.Status)
85 return errors.New("added an item to a section the enum does not list")
71 }
72 if !strings.Contains(err.Error(), "Unknown element 'sunk' for enum") {
73 return fmt.Errorf("adding status %q: got %w, want the server's refusal", sunk.Status, err)
74 }
86 }
75 fmt.Fprintf(output, "status %q refused: not one of the Enum8 labels\n", sunk.Status)
87 fmt.Fprintf(output, "refused section drinks: %v\n", err)
76 return nil
88 return nil
77}
89}
90
91// soldOut returns a note for an item that has sold out, comparing against the typed
92// constant rather than a string.
93//
94// Takes status (menu.Status) which is the item's status.
95//
96// Returns string which is the note, or empty when the item is available.
97func soldOut(status menu.Status) string {
98 if status == menu.SoldOut {
99 return " (sold out)"
100 }
101 return ""
102}