postgresql 调用json_Object_keys does not exist
时间: 2024-03-16 20:42:11 浏览: 28
这个问题可能是因为你的 PostgreSQL 版本太老了,或者你的数据库没有安装 json 扩展。json_Object_keys 是在 PostgreSQL 9.3 版本及以上引入的,如果你的版本低于这个,那么这个函数就不会存在。你可以尝试升级 PostgreSQL 到最新版本,或者安装 json 扩展。安装 json 扩展的方法是执行以下 SQL 命令:
```
CREATE EXTENSION IF NOT EXISTS "json";
```
执行完毕后,你就可以使用 json_Object_keys 函数了。
相关问题
string_agg(text) does not exist
This is not a question, but a statement that may be encountered in PostgreSQL. It means that the SQL function `string_agg` with the argument type `text` does not exist in the current database. `string_agg` is a function that concatenates values into a single string, with a specified delimiter.
To solve this issue, you can create the function with the correct argument type by executing the following SQL command:
```
CREATE AGGREGATE string_agg (text)
(
sfunc = textcat,
stype = text,
delimiter = ','
);
```
This will create the `string_agg` function with the argument type `text`.
"timestamp_without_time_zone" does not exist
"timestamp_without_time_zone" is not a valid data type in PostgreSQL. The closest equivalent is "timestamp" without time zone. If you want to store timestamps without time zone information in PostgreSQL, you can use the "timestamp" data type and set the time zone to UTC. For example:
```
CREATE TABLE mytable (
id SERIAL PRIMARY KEY,
created_at TIMESTAMP NOT NULL DEFAULT now()::timestamp without time zone
);
```
This will create a table with a "created_at" column that stores the timestamp without time zone information.