使用java中的预准备语句插入自定义SQL类型 [英] Inserting into custom SQL types with prepared statements in java

问题描述

我有一些自定义类型。它们基本上都是枚举。以下是它们的示例：

I have some custom types. They are all basically enums. Here is an example of what they look like:

CREATE TYPE card_suit AS ENUM
   ('spades',
    'clubs',
    'hearts',
    'diamonds');

我在Java中有一些准备好的语句，看起来像这样：

And I have some prepared statements in Java, which look something like this:

// Setup stuff up here.
sql = "INSERT INTO foo (suit) VALUES (?)";
st.setString(1, 'spades');
st.executeUpdate(sql);

Java给了我一些令人讨厌的例外：

And Java gives me some nasty exceptions like this:

org.postgresql.util.PSQLException: ERROR: column "suit" is of type card_suit but expression is of type character varying
Hint: You will need to rewrite or cast the expression.

他们很高兴给我一个提示，但我不确定如何遵循它。

It's nice of them to give me a hint, but I'm not sure exactly how to follow it.

推荐答案

您是否尝试将列转换为枚举？

Have you tried to cast column to enum?

// Setup stuff up here.
sql = "INSERT INTO foo (suit) VALUES (?::card_suit)";
st.setString(1, 'spades');
st.executeUpdate(sql);

在Java enums和PostgreSQL枚举之间转换A web coding blog的文章，包含样本：

Explained in Convert between Java enums and PostgreSQL enums article of 'A web coding blog' with samples:

INSERT INTO pet (pet_id, pet_type, name) 
         VALUES (?, CAST(? AS animal_type), ?);

--or

INSERT INTO pet (pet_id, pet_type, name) 
         VALUES (?, ?::animal_type, ?);

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