使用PreparedStatement将一系列Java Enum持久保存到Postgres Enu

发布时间：2020-12-15 08:33:44 所属栏目：Java 来源：网络整理

导读：我有一个 Java Enum： 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

我有一个 Java Enum：

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,其中包含一个包含“设备”项目数组的列：

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”枚举的数组,我希望使用Prepared Statement持久保存到数据库,而对于我的生活,我无法弄清楚如何做到这一点.

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???????????

解决方法

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());

（编辑：李大同）

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