| 2063 | } |
| 2064 | |
| 2065 | func ExampleBucket_Delete() { |
| 2066 | // Open the database. |
| 2067 | db, err := bolt.Open(tempfile(), 0600, nil) |
| 2068 | if err != nil { |
| 2069 | log.Fatal(err) |
| 2070 | } |
| 2071 | defer os.Remove(db.Path()) |
| 2072 | |
| 2073 | // Start a write transaction. |
| 2074 | if err := db.Update(func(tx *bolt.Tx) error { |
| 2075 | // Create a bucket. |
| 2076 | b, err := tx.CreateBucket([]byte("widgets")) |
| 2077 | if err != nil { |
| 2078 | return err |
| 2079 | } |
| 2080 | |
| 2081 | // Set the value "bar" for the key "foo". |
| 2082 | if err := b.Put([]byte("foo"), []byte("bar")); err != nil { |
| 2083 | return err |
| 2084 | } |
| 2085 | |
| 2086 | // Retrieve the key back from the database and verify it. |
| 2087 | value := b.Get([]byte("foo")) |
| 2088 | fmt.Printf("The value of 'foo' was: %s\n", value) |
| 2089 | |
| 2090 | return nil |
| 2091 | }); err != nil { |
| 2092 | log.Fatal(err) |
| 2093 | } |
| 2094 | |
| 2095 | // Delete the key in a different write transaction. |
| 2096 | if err := db.Update(func(tx *bolt.Tx) error { |
| 2097 | return tx.Bucket([]byte("widgets")).Delete([]byte("foo")) |
| 2098 | }); err != nil { |
| 2099 | log.Fatal(err) |
| 2100 | } |
| 2101 | |
| 2102 | // Retrieve the key again. |
| 2103 | if err := db.View(func(tx *bolt.Tx) error { |
| 2104 | value := tx.Bucket([]byte("widgets")).Get([]byte("foo")) |
| 2105 | if value == nil { |
| 2106 | fmt.Printf("The value of 'foo' is now: nil\n") |
| 2107 | } |
| 2108 | return nil |
| 2109 | }); err != nil { |
| 2110 | log.Fatal(err) |
| 2111 | } |
| 2112 | |
| 2113 | // Close database to release file lock. |
| 2114 | if err := db.Close(); err != nil { |
| 2115 | log.Fatal(err) |
| 2116 | } |
| 2117 | |
| 2118 | // Output: |
| 2119 | // The value of 'foo' was: bar |
| 2120 | // The value of 'foo' is now: nil |
| 2121 | } |
| 2122 | |