Sql hstore:无法连接两个hstore值

使用v9.3的Postgres新手希望利用

hstore

当我尝试连接两个

hstore

值时，会出现一个奇怪的错误：

SELECT p.properties->'name' || p.properties->'age' FROM people p where p.id=1;

错误是：

ERROR:  operator does not exist: text -> unknown
LINE 1: select n.properties->'name' || n.properties->'age' from n...
                                                   ^
HINT:  No operator matches the given name and argument type(s). You might need to add explicit type casts.

我也试过了，没关系：

SELECT p.properties->'name'::text || p.properties->'age'::text FROM people p where p.id=1;

然而，我能做到

不能从同一个hstore中连接两个hstore值吗

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感谢任何指点

您可以按原样使用CAST功能：

SELECT CAST(p.properties->'name' AS text) || CAST(p.properties->'age' AS text) FROM people p where p.id=1;

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这就解决了问题。事实证明，您只需强制转换第二个和后续的hstore引用，第一个可以保持不变。奇怪的谢谢你的帮助！

SELECT CAST(p.properties->'name' AS text) || CAST(p.properties->'age' AS text) FROM people p where p.id=1;