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docs: sample for the UUID data type #439

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7d6ee5f
feat: uuid data type
olavloite May 20, 2025
7b391b4
Merge branch 'main' into uuid-sample
olavloite Jun 25, 2025
a8b5faa
Merge branch 'main' into uuid-sample
olavloite Aug 18, 2025
3878b7f
Merge branch 'main' into uuid-sample
olavloite Mar 5, 2026
74dfa13
chore: add uuid to scanned columns
olavloite Mar 5, 2026
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34 changes: 22 additions & 12 deletions examples/data-types/main.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -23,6 +23,7 @@ import (

"cloud.google.com/go/civil"
"cloud.google.com/go/spanner"
"github.com/google/uuid"
spannerdriver "github.com/googleapis/go-sql-spanner"
"github.com/googleapis/go-sql-spanner/examples"
)
Expand All @@ -38,6 +39,7 @@ var createTableStatement = `CREATE TABLE AllTypes (
numeric NUMERIC,
date DATE,
timestamp TIMESTAMP,
col_uuid UUID,
boolArray ARRAY<BOOL>,
stringArray ARRAY<STRING(MAX)>,
bytesArray ARRAY<BYTES(MAX)>,
Expand All @@ -47,6 +49,7 @@ var createTableStatement = `CREATE TABLE AllTypes (
numericArray ARRAY<NUMERIC>,
dateArray ARRAY<DATE>,
timestampArray ARRAY<TIMESTAMP>,
uuidArray ARRAY<UUID>,
) PRIMARY KEY (key)`

// Sample showing how to work with the different data types that are supported by Cloud Spanner:
Expand All @@ -68,15 +71,16 @@ func dataTypes(projectId, instanceId, databaseId string) error {

// Insert a test row with all non-null values using DML and native types.
if _, err := db.ExecContext(ctx, `INSERT INTO AllTypes (
key, bool, string, bytes, int64, float32, float64, numeric, date, timestamp,
boolArray, stringArray, bytesArray, int64Array, float32Array, float64Array, numericArray, dateArray, timestampArray)
VALUES (@key, @bool, @string, @bytes, @int64, @float32, @float64, @numeric, @date, @timestamp,
@boolArray, @stringArray, @bytesArray, @int64Array, @float32Array, @float64Array, @numericArray, @dateArray, @timestampArray)`,
1, true, "string", []byte("bytes"), 100, float32(3.14), 3.14, *big.NewRat(1, 1), civil.DateOf(time.Now()), time.Now(),
key, bool, string, bytes, int64, float32, float64, numeric, date, timestamp, col_uuid,
boolArray, stringArray, bytesArray, int64Array, float32Array, float64Array, numericArray, dateArray, timestampArray, uuidArray)
VALUES (@key, @bool, @string, @bytes, @int64, @float32, @float64, @numeric, @date, @timestamp, @uuid,
@boolArray, @stringArray, @bytesArray, @int64Array, @float32Array, @float64Array, @numericArray, @dateArray, @timestampArray, @uuidArray)`,
1, true, "string", []byte("bytes"), 100, float32(3.14), 3.14, *big.NewRat(1, 1), civil.DateOf(time.Now()), time.Now(), uuid.New(),
[]bool{true, false}, []string{"s1", "s2"}, [][]byte{[]byte("b1"), []byte("b2")}, []int64{1, 2},
[]float32{1.1, 2.2}, []float64{1.1, 2.2}, []big.Rat{*big.NewRat(1, 2), *big.NewRat(1, 3)},
[]civil.Date{{Year: 2021, Month: 10, Day: 12}, {Year: 2021, Month: 10, Day: 13}},
[]time.Time{time.Now(), time.Now().Add(24 * time.Hour)}); err != nil {
[]time.Time{time.Now(), time.Now().Add(24 * time.Hour)},
[]uuid.UUID{uuid.New(), uuid.New()}); err != nil {
return fmt.Errorf("failed to insert a record with all non-null values using DML: %v", err)
}
fmt.Print("Inserted a test record with all non-null values\n")
Expand Down Expand Up @@ -121,8 +125,8 @@ func dataTypes(projectId, instanceId, databaseId string) error {
"SELECT * FROM AllTypes WHERE key=@key",
spannerdriver.ExecOptions{DecodeToNativeArrays: true},
1).Scan(
&r1.key, &r1.bool, &r1.string, &r1.bytes, &r1.int64, &r1.float32, &r1.float64, &r1.numeric, &r1.date, &r1.timestamp,
&r1.boolArray, &r1.stringArray, &r1.bytesArray, &r1.int64Array, &r1.float32Array, &r1.float64Array, &r1.numericArray, &r1.dateArray, &r1.timestampArray,
&r1.key, &r1.bool, &r1.string, &r1.bytes, &r1.int64, &r1.float32, &r1.float64, &r1.numeric, &r1.date, &r1.timestamp, &r1.uuid,
&r1.boolArray, &r1.stringArray, &r1.bytesArray, &r1.int64Array, &r1.float32Array, &r1.float64Array, &r1.numericArray, &r1.dateArray, &r1.timestampArray, &r1.uuidArray,
); err != nil {
return fmt.Errorf("failed to get row with non-null values: %v", err)
}
Expand All @@ -131,8 +135,8 @@ func dataTypes(projectId, instanceId, databaseId string) error {
// You can also use the spanner.Null* types to get data. These types can store both non-null and null values.
var r2 nullTypes
if err := db.QueryRowContext(ctx, "SELECT * FROM AllTypes WHERE key=@key", 1).Scan(
&r2.key, &r2.bool, &r2.string, &r2.bytes, &r2.int64, &r2.float32, &r2.float64, &r2.numeric, &r2.date, &r2.timestamp,
&r2.boolArray, &r2.stringArray, &r2.bytesArray, &r2.int64Array, &r2.float32Array, &r2.float64Array, &r2.numericArray, &r2.dateArray, &r2.timestampArray,
&r2.key, &r2.bool, &r2.string, &r2.bytes, &r2.int64, &r2.float32, &r2.float64, &r2.numeric, &r2.date, &r2.timestamp, &r2.uuid,
&r2.boolArray, &r2.stringArray, &r2.bytesArray, &r2.int64Array, &r2.float32Array, &r2.float64Array, &r2.numericArray, &r2.dateArray, &r2.timestampArray, &r2.uuidArray,
); err != nil {
return fmt.Errorf("failed to get row with null values: %v", err)
}
Expand All @@ -143,8 +147,8 @@ func dataTypes(projectId, instanceId, databaseId string) error {
// use spanner.NullNumeric and spanner.NullDate.
var r3 sqlNullTypes
if err := db.QueryRowContext(ctx, "SELECT * FROM AllTypes WHERE key=@key", 1).Scan(
&r3.key, &r3.bool, &r3.string, &r3.bytes, &r3.int64, &r3.float32, &r3.float64, &r3.numeric, &r3.date, &r3.timestamp,
&r3.boolArray, &r3.stringArray, &r3.bytesArray, &r3.int64Array, &r3.float32Array, &r3.float64Array, &r3.numericArray, &r3.dateArray, &r3.timestampArray,
&r3.key, &r3.bool, &r3.string, &r3.bytes, &r3.int64, &r3.float32, &r3.float64, &r3.numeric, &r3.date, &r3.timestamp, &r3.uuid,
&r3.boolArray, &r3.stringArray, &r3.bytesArray, &r3.int64Array, &r3.float32Array, &r3.float64Array, &r3.numericArray, &r3.dateArray, &r3.timestampArray, &r3.uuidArray,
); err != nil {
return fmt.Errorf("failed to get row with null values using Go sql null types: %v", err)
}
Expand All @@ -164,6 +168,7 @@ type nativeTypes struct {
numeric big.Rat
date civil.Date
timestamp time.Time
uuid uuid.UUID
// Array types use Null* types by default, because an array may always
// contain NULL elements in the array itself (even if the ARRAY column is
// defined as NOT NULL). The Spanner database/sql driver can also return
Expand All @@ -179,6 +184,7 @@ type nativeTypes struct {
numericArray []spanner.NullNumeric
dateArray []civil.Date
timestampArray []time.Time
uuidArray []uuid.UUID
}

type nullTypes struct {
Expand All @@ -192,6 +198,7 @@ type nullTypes struct {
numeric spanner.NullNumeric
date spanner.NullDate
timestamp spanner.NullTime
uuid spanner.NullUUID
boolArray []spanner.NullBool
stringArray []spanner.NullString
bytesArray [][]byte
Expand All @@ -201,6 +208,7 @@ type nullTypes struct {
numericArray []spanner.NullNumeric
dateArray []spanner.NullDate
timestampArray []spanner.NullTime
uuidArray []uuid.UUID
}

type sqlNullTypes struct {
Expand All @@ -214,6 +222,7 @@ type sqlNullTypes struct {
numeric spanner.NullNumeric // There is no sql.NullNumeric type
date spanner.NullDate // There is no sql.NullDate type
timestamp sql.NullTime
uuid spanner.NullUUID // There is no sql.NullUUID type
// Array types must always use the spanner.Null* structs.
boolArray []spanner.NullBool
stringArray []spanner.NullString
Expand All @@ -224,6 +233,7 @@ type sqlNullTypes struct {
numericArray []spanner.NullNumeric
dateArray []spanner.NullDate
timestampArray []spanner.NullTime
uuidArray []uuid.UUID
}

func main() {
Expand Down
27 changes: 23 additions & 4 deletions examples/emulator_runner.go
View file
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Original file line number Diff line number Diff line change
Expand Up @@ -22,14 +22,16 @@ import (
"os"
"time"

"cloud.google.com/go/spanner"
database "cloud.google.com/go/spanner/admin/database/apiv1"
databasepb "cloud.google.com/go/spanner/admin/database/apiv1/databasepb"
"cloud.google.com/go/spanner/admin/database/apiv1/databasepb"
instance "cloud.google.com/go/spanner/admin/instance/apiv1"
instancepb "cloud.google.com/go/spanner/admin/instance/apiv1/instancepb"
"cloud.google.com/go/spanner/admin/instance/apiv1/instancepb"
"github.com/docker/docker/api/types/container"
"github.com/docker/docker/api/types/image"
"github.com/docker/docker/client"
"github.com/docker/go-connections/nat"
"google.golang.org/grpc/codes"
)

var cli *client.Client
Expand Down Expand Up @@ -69,6 +71,10 @@ func RunSampleOnEmulatorWithDialect(sample func(string, string, string) error, d
}

func startEmulator() error {
if os.Getenv("SPANNER_EMULATOR_HOST") != "" {
return nil
}

ctx := context.Background()
if err := os.Setenv("SPANNER_EMULATOR_HOST", "localhost:9010"); err != nil {
return err
Expand Down Expand Up @@ -130,7 +136,7 @@ func createInstance(projectId, instanceId string) error {
if err != nil {
return err
}
defer instanceAdmin.Close()
defer silentClose(instanceAdmin)
op, err := instanceAdmin.CreateInstance(ctx, &instancepb.CreateInstanceRequest{
Parent: fmt.Sprintf("projects/%s", projectId),
InstanceId: instanceId,
Expand All @@ -141,6 +147,9 @@ func createInstance(projectId, instanceId string) error {
},
})
if err != nil {
if spanner.ErrCode(err) == codes.AlreadyExists {
return nil
}
return fmt.Errorf("could not create instance %s: %v", fmt.Sprintf("projects/%s/instances/%s", projectId, instanceId), err)
}
// Wait for the instance creation to finish.
Expand All @@ -156,7 +165,13 @@ func createSampleDB(projectId, instanceId, databaseId string, dialect databasepb
if err != nil {
return err
}
defer databaseAdminClient.Close()
defer silentClose(databaseAdminClient)

// Drop the database if it already exists.
_ = databaseAdminClient.DropDatabase(ctx, &databasepb.DropDatabaseRequest{
Database: fmt.Sprintf("projects/%s/instances/%s/databases/%s", projectId, instanceId, databaseId),
})

var createStatement string
if dialect == databasepb.DatabaseDialect_POSTGRESQL {
createStatement = fmt.Sprintf(`CREATE DATABASE "%s"`, databaseId)
Expand Down Expand Up @@ -189,3 +204,7 @@ func stopEmulator() {
log.Printf("failed to stop emulator: %v\n", err)
}
}

func silentClose(c io.Closer) {
_ = c.Close()
}
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