在Postgres中增加字符变化类型的大小而不会丢失数据 [英] Increasing the size of character varying type in postgres without data loss

问题描述

我需要在不丢失数据的情况下增加postgres数据库表中的character changes（60）字段的大小。

I need to increase the size of a character varying(60) field in a postgres database table without data loss.

我有此命令

alter table client_details alter column name set character varying(200);

此命令是否将字段大小从60增加到200而不会丢失数据？

will this command increase the the field size from 60 to 200 without data loss?

推荐答案

引用此文档，不会丢失任何数据，更改列仅将旧数据转换为新数据，因此字符数据之间的转换应该可以。但是我认为您的语法不正确，请参阅我前面提到的文档。我认为您应该使用以下语法：

Referring to this documentation, there would be no data loss, alter column only casts old data to new data so a cast between character data should be fine. But I don't think your syntax is correct, see the documentation I mentioned earlier. I think you should be using this syntax :

ALTER [COLUMN]列TYPE类型[
USING expression]

ALTER [ COLUMN ] column TYPE type [ USING expression ]

注意，创建表，填充表并进行测试不是更容易吗？

And as a note, wouldn't it be easier to just create a table, populate it and test :)

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