JSON columns: DuckDB and CockroachDB
Every file of the DuckDB and CockroachDB versions side by side, with the lines that differ marked.
Configuration
sgl.yamldiffers
DuckDB
CockroachDB
1
version: 11
version: 12
2
3
databases:3
databases:4
- name: chippy4
- name: orders5
dialect: duckdb5
dialect: postgres6
migrations: db/migrations6
migrations: db/migrations7
queries: db/queries7
queries: db/queries8
go:8
go:9
package: store9
package: store10
out: internal/store10
out: internal/store11
driver: database/sql12
json_tags:13
case: camel14
omitempty: true15
struct_tags:16
db: "{name}"17
empty_slices: trueMigrations
db/migrations/0001_orders.up.sqldiffers
DuckDB
CockroachDB
1
CREATE SEQUENCE order_ids;2
3
CREATE TABLE orders (1
CREATE TABLE orders (4
id BIGINT PRIMARY KEY DEFAULT nextval('order_ids'),2
id BIGINT GENERATED ALWAYS AS IDENTITY PRIMARY KEY,5
customer VARCHAR NOT NULL,3
customer TEXT NOT NULL,6
basket JSON NOT NULL,4
basket JSONB NOT NULL,7
delivery JSON5
delivery JSONB8
);6
);db/migrations/0001_orders.down.sqldiffers
DuckDB
CockroachDB
1
DROP TABLE orders;1
DROP TABLE orders;2
DROP SEQUENCE order_ids;Queries
PlaceOrderidentical
DuckDB · db/queries/orders.sql
CockroachDB · db/queries/orders.sql
1
-- sgl.query(PlaceOrder, exec)1
-- sgl.query(PlaceOrder, exec)2
INSERT INTO orders (customer, basket, delivery) VALUES ($1, $2, $3);2
INSERT INTO orders (customer, basket, delivery) VALUES ($1, $2, $3);GetOrderidentical
DuckDB · db/queries/orders.sql
CockroachDB · db/queries/orders.sql
1
-- sgl.query(GetOrder, one)1
-- sgl.query(GetOrder, one)2
SELECT id, customer, basket, delivery FROM orders WHERE id = $1;2
SELECT id, customer, basket, delivery FROM orders WHERE id = $1;OrdersWithFishdiffers
DuckDB · db/queries/orders.sql
CockroachDB · db/queries/orders.sql
1
-- sgl.query(OrdersWithFish, many)1
-- sgl.query(OrdersWithFish, many)2
-- $1 as sgl.param(fish, type: varchar)2
-- $1 as sgl.param(fish, type: text)3
SELECT3
SELECT4
id,4
id,5
customer,5
customer,6
basket -> '$.extras' AS extras,6
basket -> 'extras' AS extras,7
delivery ->> '$.address' AS address7
delivery ->> 'address' AS delivery_address8
FROM orders8
FROM orders9
WHERE basket ->> '$.fish' = $19
WHERE basket ->> 'fish' = $110
ORDER BY id;10
ORDER BY id;OrdersContainingonly CockroachDB
DuckDB · not in this version
CockroachDB · db/queries/orders.sql
1
-- sgl.query(OrdersContaining, many)2
-- $1 as sgl.param(subset)3
SELECT id, customer4
FROM orders5
WHERE basket @> $1::jsonb6
ORDER BY id;What sgl generates
PlaceOrderidentical
DuckDB
CockroachDB
1
func (queries *Queries) PlaceOrder(ctx context.Context, params PlaceOrderParams) error1
func (queries *Queries) PlaceOrder(ctx context.Context, params PlaceOrderParams) error2
2
3
type PlaceOrderParams struct {3
type PlaceOrderParams struct {4
Customer string4
Customer string5
Basket JSON5
Basket JSON6
Delivery JSON6
Delivery JSON7
}7
}8
8
9
type JSON []byte9
type JSON []byteGetOrderdiffers
DuckDB
CockroachDB
1
func (queries *Queries) GetOrder(ctx context.Context, id int64) (GetOrderRow, error)1
func (queries *Queries) GetOrder(ctx context.Context, id int64) (GetOrderRow, error)2
2
3
type GetOrderRow struct {3
type GetOrderRow struct {4
ID int64 `json:"id"`4
ID int64 `json:"id,omitempty" db:"id"`5
Customer string `json:"customer"`5
Customer string `json:"customer,omitempty" db:"customer"`6
Basket JSON `json:"basket"`6
Basket JSON `json:"basket,omitempty" db:"basket"`7
Delivery JSON `json:"delivery"`7
Delivery JSON `json:"delivery,omitempty" db:"delivery"`8
}8
}9
9
10
type JSON []byte10
type JSON []byteOrdersWithFishdiffers
DuckDB
CockroachDB
1
func (queries *Queries) OrdersWithFish(ctx context.Context, fish string) ([]OrdersWithFishRow, error)1
func (queries *Queries) OrdersWithFish(ctx context.Context, fish string) ([]OrdersWithFishRow, error)2
2
3
type OrdersWithFishRow struct {3
type OrdersWithFishRow struct {4
ID int64 `json:"id"`4
ID int64 `json:"id,omitempty" db:"id"`5
Customer string `json:"customer"`5
Customer string `json:"customer,omitempty" db:"customer"`6
Extras JSON `json:"extras"`6
Extras JSON `json:"extras,omitempty" db:"extras"`7
Address *string `json:"address"`7
DeliveryAddress *string `json:"deliveryAddress,omitempty" db:"delivery_address"`8
}8
}9
9
10
type JSON []byte10
type JSON []byteOrdersContainingonly CockroachDB
DuckDB · not in this version
CockroachDB
1
func (queries *Queries) OrdersContaining(ctx context.Context, subset JSON) ([]OrdersContainingRow, error)2
3
type JSON []byte4
5
type OrdersContainingRow struct {6
ID int64 `json:"id,omitempty" db:"id"`7
Customer string `json:"customer,omitempty" db:"customer"`8
}The program
example.godiffers
DuckDB
CockroachDB
1
package main1
package main2
2
3
import (3
import (4
"context"4
"context"5
"database/sql"5
"database/sql"6
"encoding/json"6
"encoding/json"7
"fmt"7
"fmt"8
"io"8
"io"9
"reflect"10
"strings"9
11
10
"seagull.sh/seagull/examples/duckdb/006_json/internal/store"12
"seagull.sh/seagull/examples/postgres/006_json/internal/store"11
)13
)12
14
13
// basket is the document an order's basket column holds.15
// basket is the document an order's basket column holds.14
type basket struct {16
type basket struct {15
// Fish is the fish the order is for.17
// Fish is the fish the order is for.16
Fish string `json:"fish"`18
Fish string `json:"fish"`17
19
18
// Portions is how many portions of fish and chips.20
// Portions is how many portions of fish and chips.19
Portions int `json:"portions"`21
Portions int `json:"portions"`20
22
21
// Extras lists the sides.23
// Extras lists the sides.22
Extras []string `json:"extras"`24
Extras []string `json:"extras"`23
}25
}24
26
25
// delivery is the document an order's delivery column holds, when the order is delivered.27
// delivery is the document an order's delivery column holds, when the order is delivered.26
type delivery struct {28
type delivery struct {27
// Address is where the order goes.29
// Address is where the order goes.28
Address string `json:"address"`30
Address string `json:"address"`29
}31
}30
32
31
// run places three chip shop orders and reads them back. A JSON column read by a query33
// run places three chip shop orders and reads them back. A JSONB column becomes the32
// becomes the generated store.JSON type, which holds the raw document as bytes: decode it34
// generated store.JSON type, which holds the raw document as bytes: encode a value into33
// with json.Unmarshal. A nil store.JSON is SQL NULL.35
// it with json.Marshal and decode it with json.Unmarshal. A nil store.JSON is SQL NULL.34
//35
// The generated SQL casts each JSON column it reads to VARCHAR, so store.JSON holds the36
// document as DuckDB stored it, the keys in the order they were written.37
//36
//38
// PlaceOrder takes its documents as store.JSON too, and the generated code hands37
// JSONB stores a parsed document, not the text it was sent, and writes it back in its own39
// duckdb-go their text; DuckDB's JSON type is VARCHAR underneath and checks the text as38
// form: a space after each comma and colon, keys reordered and duplicate keys dropped, so40
// it is stored.39
// compare documents by decoding them, not by their bytes.41
//40
//42
// OrdersWithFish filters with ->>, which extracts a value as text, and selects with ->,41
// OrdersWithFish filters with ->>, which extracts a value as text, and selects with ->,43
// which extracts a JSON fragment, so Extras is store.JSON again. Address is *string42
// which extracts a JSONB fragment, so Extras is store.JSON again. DeliveryAddress is44
// because ->> gives NULL when the delivery column or its address is missing.43
// *string because ->> gives NULL when the delivery column or its address is missing. The44
// ->> comparison's parameter is pinned with sgl.param(fish, type: text), as inference45
// leaves it as any. OrdersContaining uses @>, which matches a document containing the one46
// bound to $1::jsonb.45
//47
//48
// The rows go straight out as JSON, as an HTTP handler would send them, so sgl.yaml49
// shapes the generated structs for that: go.json_tags writes each field's json tag in50
// camel case with omitempty, so delivery_address is "deliveryAddress" and a nil one is51
// left out; go.struct_tags adds a db tag holding the column's name, {name}, for libraries52
// that map columns by tag; and go.empty_slices makes a many method return an empty slice53
// when no row matches, which encodes as [] rather than null.54
//46
// Takes database (*sql.DB) which is a migrated database.55
// Takes database (*sql.DB) which is a migrated database.47
// Takes output (io.Writer) which receives the decoded orders and the search.56
// Takes output (io.Writer) which receives the decoded orders and the searches.48
//57
//49
// Returns error when a query fails or a document does not encode or decode.58
// Returns error when a query fails or a document does not encode or decode.50
func run(ctx context.Context, database *sql.DB, output io.Writer) error {59
func run(ctx context.Context, database *sql.DB, output io.Writer) error {51
queries := store.New(database)60
queries := store.New(database)52
61
53
orders := []struct {62
orders := []struct {54
customer string63
customer string55
basket basket64
basket basket56
delivery *delivery65
delivery *delivery57
}{66
}{58
{customer: "Steven", basket: basket{Fish: "cod", Portions: 2, Extras: []string{"mushy peas", "curry sauce"}}},67
{customer: "Steven", basket: basket{Fish: "cod", Portions: 2, Extras: []string{"mushy peas", "curry sauce"}}},59
{customer: "Gwen", basket: basket{Fish: "haddock", Portions: 1, Extras: []string{}}},68
{customer: "Gwen", basket: basket{Fish: "haddock", Portions: 1, Extras: []string{}}},60
{customer: "Morwenna", basket: basket{Fish: "cod", Portions: 1, Extras: []string{"pickled egg"}}, delivery: &delivery{Address: "4 Harbour Row"}},69
{customer: "Morwenna", basket: basket{Fish: "cod", Portions: 1, Extras: []string{"pickled egg"}}, delivery: &delivery{Address: "4 Harbour Row"}},61
}70
}62
for _, order := range orders {71
for _, order := range orders {63
encodedBasket, err := json.Marshal(order.basket)72
encodedBasket, err := json.Marshal(order.basket)64
if err != nil {73
if err != nil {65
return fmt.Errorf("encoding %s's basket: %w", order.customer, err)74
return fmt.Errorf("encoding %s's basket: %w", order.customer, err)66
}75
}67
parameters := store.PlaceOrderParams{Customer: order.customer, Basket: encodedBasket, Delivery: nil}76
parameters := store.PlaceOrderParams{Customer: order.customer, Basket: encodedBasket, Delivery: nil}68
if order.delivery != nil {77
if order.delivery != nil {69
encodedDelivery, err := json.Marshal(order.delivery)78
encodedDelivery, err := json.Marshal(order.delivery)70
if err != nil {79
if err != nil {71
return fmt.Errorf("encoding %s's delivery: %w", order.customer, err)80
return fmt.Errorf("encoding %s's delivery: %w", order.customer, err)72
}81
}73
parameters.Delivery = encodedDelivery82
parameters.Delivery = encodedDelivery74
}83
}75
if err := queries.PlaceOrder(ctx, parameters); err != nil {84
if err := queries.PlaceOrder(ctx, parameters); err != nil {76
return fmt.Errorf("placing %s's order: %w", order.customer, err)85
return fmt.Errorf("placing %s's order: %w", order.customer, err)77
}86
}78
}87
}79
88
80
first, err := queries.GetOrder(ctx, 1)89
first, err := queries.GetOrder(ctx, 1)81
if err != nil {90
if err != nil {82
return fmt.Errorf("getting order 1: %w", err)91
return fmt.Errorf("getting order 1: %w", err)83
}92
}84
var decoded basket93
var decoded basket85
if err := json.Unmarshal(first.Basket, &decoded); err != nil {94
if err := json.Unmarshal(first.Basket, &decoded); err != nil {86
return fmt.Errorf("decoding order 1's basket: %w", err)95
return fmt.Errorf("decoding order 1's basket: %w", err)87
}96
}88
fmt.Fprintf(output, "order 1 stored %s\n", first.Basket)97
fmt.Fprintf(output, "order 1 decoded: %d x %s with %v, delivery is NULL: %t\n", decoded.Portions, decoded.Fish, decoded.Extras, first.Delivery == nil)89
fmt.Fprintf(output, "decoded: %d x %s with %v, delivery is NULL: %t\n", decoded.Portions, decoded.Fish, decoded.Extras, first.Delivery == nil)90
98
91
cod, err := queries.OrdersWithFish(ctx, "cod")99
cod, err := queries.OrdersWithFish(ctx, "cod")92
if err != nil {100
if err != nil {93
return fmt.Errorf("finding cod orders: %w", err)101
return fmt.Errorf("finding cod orders: %w", err)94
}102
}95
fmt.Fprintln(output, "\ncod orders:")103
fmt.Fprintln(output, "\ncod orders:")96
for _, order := range cod {104
for _, order := range cod {97
address := "collecting"105
address := "collecting"98
if order.Address != nil {106
if order.DeliveryAddress != nil {99
address = "to " + *order.Address107
address = "to " + *order.DeliveryAddress100
}108
}101
fmt.Fprintf(output, " order %d %-9s extras %-30s %s\n", order.ID, order.Customer, order.Extras, address)109
fmt.Fprintf(output, " order %d %-9s extras %-30s %s\n", order.ID, order.Customer, order.Extras, address)102
}110
}111
if err := writeJSON(output, "cod orders as JSON", cod); err != nil {112
return err113
}114
115
plaice, err := queries.OrdersWithFish(ctx, "plaice")116
if err != nil {117
return fmt.Errorf("finding plaice orders: %w", err)118
}119
if err := writeJSON(output, "plaice orders as JSON", plaice); err != nil {120
return err121
}122
field, _ := reflect.TypeFor[store.OrdersWithFishRow]().FieldByName("DeliveryAddress")123
fmt.Fprintf(output, "DeliveryAddress is tagged %s\n", field.Tag)124
125
subset := store.JSON(`{"extras": ["pickled egg"]}`)126
containing, err := queries.OrdersContaining(ctx, subset)127
if err != nil {128
return fmt.Errorf("finding orders containing %s: %w", subset, err)129
}130
customers := make([]string, 0, len(containing))131
for _, order := range containing {132
customers = append(customers, order.Customer)133
}134
fmt.Fprintf(output, "\norders containing %s: %s\n", subset, strings.Join(customers, ", "))103
return nil135
return nil104
}136
}137
138
// writeJSON writes rows encoded as JSON, as an HTTP handler would send them, after a139
// label.140
//141
// Takes output (io.Writer) which receives the label and the document.142
// Takes label (string) which says what the rows are.143
// Takes rows (any) which are the rows to encode.144
//145
// Returns error when the rows do not encode.146
func writeJSON(output io.Writer, label string, rows any) error {147
encoded, err := json.Marshal(rows)148
if err != nil {149
return fmt.Errorf("encoding %s: %w", label, err)150
}151
fmt.Fprintf(output, "%s: %s\n", label, encoded)152
return nil153
}