More JSON/B examples. (#127)

driver/json_test.go

@@ -21,8 +21,8 @@ func Example_json() {
 		CREATE TABLE orders (
 			cart_id INTEGER PRIMARY KEY,
 			user_id INTEGER NOT NULL,
-			cart    TEXT
-		);
+			cart    BLOB -- stored as JSONB
+		) STRICT;
 	`)
 	if err != nil {
 		log.Fatal(err)
@@ -39,7 +39,8 @@ func Example_json() {
 		Items []CartItem `json:"items"`
 	}
 
-	_, err = db.Exec(`INSERT INTO orders (user_id, cart) VALUES (?, ?)`, 123, sqlite3.JSON(Cart{
+	// convert to JSONB on insertion
+	_, err = db.Exec(`INSERT INTO orders (user_id, cart) VALUES (?, jsonb(?))`, 123, sqlite3.JSON(Cart{
 		[]CartItem{
 			{ItemID: "111", Name: "T-shirt", Quantity: 1, Price: 250},
 			{ItemID: "222", Name: "Trousers", Quantity: 1, Price: 600},
@@ -60,6 +61,24 @@ func Example_json() {
 	}
 
 	fmt.Println("total:", total)
+
+	var cart Cart
+	err = db.QueryRow(`
+		SELECT json(cart) -- convert to JSON on retrieval
+		FROM orders
+		WHERE cart_id = last_insert_rowid()
+	`).Scan(sqlite3.JSON(&cart))
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	for _, item := range cart.Items {
+		fmt.Printf("id: %s, name: %s, quantity: %d, price: %d\n",
+			item.ItemID, item.Name, item.Quantity, item.Price)
+	}
+
 	// Output:
 	// total: 850
+	// id: 111, name: T-shirt, quantity: 1, price: 250
+	// id: 222, name: Trousers, quantity: 1, price: 600
 }

json_test.go

@@ -0,0 +1,112 @@
+package sqlite3_test
+
+import (
+	"fmt"
+	"log"
+
+	"github.com/ncruces/go-sqlite3"
+	_ "github.com/ncruces/go-sqlite3/embed"
+	_ "github.com/ncruces/go-sqlite3/vfs/memdb"
+)
+
+func Example_json() {
+	db, err := sqlite3.Open("file:/test.db?vfs=memdb")
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer db.Close()
+
+	err = db.Exec(`
+		CREATE TABLE orders (
+			cart_id INTEGER PRIMARY KEY,
+			user_id INTEGER NOT NULL,
+			cart    BLOB -- stored as JSONB
+		) STRICT;
+	`)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	type CartItem struct {
+		ItemID   string `json:"id"`
+		Name     string `json:"name"`
+		Quantity int    `json:"quantity,omitempty"`
+		Price    int    `json:"price,omitempty"`
+	}
+
+	type Cart struct {
+		Items []CartItem `json:"items"`
+	}
+
+	// convert to JSONB on insertion
+	stmt, _, err := db.Prepare(`INSERT INTO orders (user_id, cart) VALUES (?, jsonb(?))`)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer stmt.Close()
+
+	if err := stmt.BindInt(1, 123); err != nil {
+		log.Fatal(err)
+	}
+
+	if err := stmt.BindJSON(2, Cart{
+		[]CartItem{
+			{ItemID: "111", Name: "T-shirt", Quantity: 1, Price: 250},
+			{ItemID: "222", Name: "Trousers", Quantity: 1, Price: 600},
+		},
+	}); err != nil {
+		log.Fatal(err)
+	}
+
+	if err := stmt.Exec(); err != nil {
+		log.Fatal(err)
+	}
+
+	sl1, _, err := db.Prepare(`
+		SELECT total(json_each.value -> 'price')
+		FROM orders, json_each(cart -> 'items')
+		WHERE cart_id = last_insert_rowid()
+	`)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer sl1.Close()
+
+	for sl1.Step() {
+		fmt.Println("total:", sl1.ColumnInt(0))
+	}
+
+	if err := sl1.Err(); err != nil {
+		log.Fatal(err)
+	}
+
+	sl2, _, err := db.Prepare(`
+		SELECT json(cart) -- convert to JSON on retrieval
+		FROM orders
+		WHERE cart_id = last_insert_rowid()
+	`)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer sl2.Close()
+
+	for sl2.Step() {
+		var cart Cart
+		if err := sl2.ColumnJSON(0, &cart); err != nil {
+			log.Fatal(err)
+		}
+		for _, item := range cart.Items {
+			fmt.Printf("id: %s, name: %s, quantity: %d, price: %d\n",
+				item.ItemID, item.Name, item.Quantity, item.Price)
+		}
+	}
+
+	if err := sl2.Err(); err != nil {
+		log.Fatal(err)
+	}
+
+	// Output:
+	// total: 850
+	// id: 111, name: T-shirt, quantity: 1, price: 250
+	// id: 222, name: Trousers, quantity: 1, price: 600
+}