java - 使用 PreparedStatement 将 Java 枚举数组持久化到 Postgres 枚举数组

Question

我有一个 Java 枚举:

public enum Equipment { Hood, Blinkers, ToungTie, CheekPieces, Visor, EyeShield, None;}

和相应的 Postgres 枚举:

CREATE TYPE equipment AS ENUM ('Hood', 'Blinkers', 'ToungTie', 'CheekPieces', 'Visor', 'EyeShield', 'None');

在我的数据库中，我有一个表，其中有一列包含“设备”项目的数组:

CREATE TABLE "Entry" (
    id bigint NOT NULL DEFAULT nextval('seq'::regclass),
    "date" character(10) NOT NULL,
    equipment equipment[]
);

最后，当我运行我的应用程序时，我有一个“设备”枚举数组，我想使用准备好的语句将其持久保存到数据库中，但我一直不知道该怎么做.

StringBuffer sb =  new StringBuffer("insert into \"Entry\" ");
sb.append("( \"date\", \"equipment \" )");
sb.append(" values ( ?, ? )");
PreparedStatement ps = db.prepareStatement(sb.toString());

ps.setString("2010-10-10");
ps.set???????????

Answer 1

你应该阅读 this .

我建议您的代码看起来更像这样:

    // A column named "date" is probably illegal and not very illustrative.  "date" is a keyword for most databases.
    // Building a string that never changes again and again is a waste of CPU and heap
    private static final String INSERT_SQL =  "insert into Entry(date,equipment) values(?,?)";

    PreparedStatement ps = db.prepareStatement(INSERT_SQL);

    // Use the type system properly.  Dates should be DATE type columns in a database.  Why string?    
    ps.setDate(entryDate);

    // You shouldn't want to insert an array of values; that's not normalized.
    ps.setString(equipmentEnumValue.name());