Question

I have a Java Enum:

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

and a corresponding Postgres enum:

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

Within my database I have a table which has a column containing an array of “equipment” items:

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

And finally when I am running my application I have an array of the “Equipment” enums which I want to persist to the database using a Prepared Statement, and for the life of me I can’t figure out how to do it.

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

You should read this.

I’d suggest that your code look more like this:

    // 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());