在下面的查询中,$isComplete 和 $isValid 以字符串形式返回。但是,它们被保存为布尔值。如何获取要返回的这些字段的布尔表示?
query =
"SELECT
data #>> '{id}' AS id,
data #>> '{name}' AS name,
data #>> '{curator}' AS curator,
data #> '{$isValid}' as \"$isValid\",
data #> '{customer}' as customer,
data #> '{$createdTS}' as \"$createdTS\",
data #> '{$updatedTS}' as \"$updatedTS\",
data #> '{$isComplete}' as \"$isComplete\",
(count(keys))::numeric as \"numProducts\"
FROM
appointment_intakes,
LATERAL jsonb_object_keys(data #> '{products}') keys
GROUP BY id"
只需将文本转换为布尔值:
create table jsonb_test (id int, data jsonb);
insert into jsonb_test values
(1, '{"is_boolean" : true}'),
(2, '{"is_boolean" : false}');
select id, data, (data->>'is_boolean')::boolean as is_boolean
from jsonb_test
where (data->>'is_boolean')::boolean
id | data | is_boolean
----+------------------------+------------
1 | {"is_boolean": true} | t
(1 row)
请注意,您还可以将其他 json 文本值转换为布尔值,示例:
insert into jsonb_test values
(3, '{"is_boolean" : "true"}'),
(4, '{"is_boolean" : "false"}'),
(5, '{"is_boolean" : "t"}'),
(6, '{"is_boolean" : "f"}'),
(7, '{"is_boolean" : "on"}'),
(8, '{"is_boolean" : "off"}');
select id, data, (data->>'is_boolean')::boolean as is_boolean
from jsonb_test
where (data->>'is_boolean')::boolean
id | data | is_boolean
----+------------------------+------------
1 | {"is_boolean": true} | t
3 | {"is_boolean": "true"} | t
5 | {"is_boolean": "t"} | t
7 | {"is_boolean": "on"} | t
(4 rows)
阅读文档中布尔类型的有效文字。
更新
Postgres 11 添加了从 JSONB 标量到数字和布尔数据类型的转换。此查询仅适用于 regular 布尔 JSONB 标量(即
true
或 false
):
select id, data, (data->'is_boolean')::boolean as is_boolean
from jsonb_test
where (data->'is_boolean')::boolean
在 Postgres 14 及更高版本中,您可以使用 JSONB 下标 删除
->
和 ()
:
select id, data, data['is_boolean']::boolean as is_boolean
from jsonb_test
where data['is_boolean']::boolean