-
Notifications
You must be signed in to change notification settings - Fork 1.7k
/
spanner_dml_update_returning.go
71 lines (64 loc) · 1.93 KB
/
spanner_dml_update_returning.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
// Copyright 2022 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package spanner
// [START spanner_update_dml_returning]
import (
"context"
"fmt"
"io"
"cloud.google.com/go/spanner"
"google.golang.org/api/iterator"
)
func updateUsingDMLReturning(w io.Writer, db string) error {
ctx := context.Background()
client, err := spanner.NewClient(ctx, db)
if err != nil {
return err
}
defer client.Close()
// Update MarketingBudget column for records satisfying
// a particular condition and returns the modified
// MarketingBudget column of the updated records using
// 'THEN RETURN MarketingBudget'.
// It is also possible to return all columns of all the
// updated records by using 'THEN RETURN *'.
_, err = client.ReadWriteTransaction(ctx, func(ctx context.Context, txn *spanner.ReadWriteTransaction) error {
stmt := spanner.Statement{
SQL: `UPDATE Albums
SET MarketingBudget = MarketingBudget * 2
WHERE SingerId = 1 and AlbumId = 1
THEN RETURN MarketingBudget`,
}
iter := txn.Query(ctx, stmt)
defer iter.Stop()
for {
row, err := iter.Next()
if err == iterator.Done {
break
}
if err != nil {
return err
}
var marketingBudget int64
if err := row.Columns(&marketingBudget); err != nil {
return err
}
fmt.Fprintf(w, "%d\n", marketingBudget)
}
fmt.Fprintf(w, "%d record(s) updated.\n", iter.RowCount)
return nil
})
return err
}
// [END spanner_update_dml_returning]