Terjemahan disediakan oleh mesin penerjemah. Jika konten terjemahan yang diberikan bertentangan dengan versi bahasa Inggris aslinya, utamakan versi bahasa Inggris.
Memperoleh panjang dan ukuran array JSON
Contoh: json_array_length
Untuk mendapatkan panjang larik dikodekan JSON, gunakan fungsi json_array_length
.
WITH dataset AS ( SELECT * FROM (VALUES (JSON '{"name": "Bob Smith", "org": "legal", "projects": [{"name":"project1", "completed":false}]}'), (JSON '{"name": "Susan Smith", "org": "engineering", "projects": [{"name":"project2", "completed":true}, {"name":"project3", "completed":true}]}'), (JSON '{"name": "Jane Smith", "org": "finance", "projects": [{"name":"project2", "completed":true}]}') ) AS t (users) ) SELECT json_extract_scalar(users, '$.name') as name, json_array_length(json_extract(users, '$.projects')) as count FROM dataset ORDER BY count DESC
Kueri ini mengembalikan hasil ini:
+---------------------+
| name | count |
+---------------------+
| Susan Smith | 2 |
+---------------------+
| Bob Smith | 1 |
+---------------------+
| Jane Smith | 1 |
+---------------------+
Contoh: json_size
Untuk mendapatkan ukuran larik atau objek dikodekan JSON, gunakan fungsi json_size
dan tentukan kolom yang berisi string JSON dan ekspresi JSONPath
untuk larik atau objek.
WITH dataset AS ( SELECT * FROM (VALUES (JSON '{"name": "Bob Smith", "org": "legal", "projects": [{"name":"project1", "completed":false}]}'), (JSON '{"name": "Susan Smith", "org": "engineering", "projects": [{"name":"project2", "completed":true},{"name":"project3", "completed":true}]}'), (JSON '{"name": "Jane Smith", "org": "finance", "projects": [{"name":"project2", "completed":true}]}') ) AS t (users) ) SELECT json_extract_scalar(users, '$.name') as name, json_size(users, '$.projects') as count FROM dataset ORDER BY count DESC
Kueri ini mengembalikan hasil ini:
+---------------------+
| name | count |
+---------------------+
| Susan Smith | 2 |
+---------------------+
| Bob Smith | 1 |
+---------------------+
| Jane Smith | 1 |
+---------------------+