fieldtype.java

用JAVA实现了,将DB装入内存,内存由DBMS控制,实现简单数据库的创建、数据表的创建、记录插入、查询以及表的删除。

package org.kdb.struct;

/**
 * Created by IntelliJ IDEA.

 * Date: 2007-11-17
 * Time: 14:08:51
 */
public enum FieldType {
    INT("int", 0), STRING("string", 1), DATE("date", 2), LONG("long", 3);

    private transient String name;
    private int index;

    private FieldType(String name, int index) {
        this.name = name;
        this.index = index;
    }

    public String getName() {
        if (name == null) {
            name = name().toLowerCase();
        }
        return name;
    }

    public int getIndex() {
        return index;
    }

    public static FieldType getType(String type) {
        String tp = type.toLowerCase();
        if (tp.equals("int")) {
            return INT;
        } else if (tp.equals("string")) {
            return STRING;
        } else if (tp.equals("date")) {
            return DATE;
        } else if (tp.equals("long")) {
            return LONG;
        } else {
            throw new IllegalArgumentException("Illegal type");
        }
    }


    public static FieldType getType(int type) {
        switch (type) {
            case 0:
                return INT;
            case 1:
                return STRING;
            case 2:
                return DATE;
            case 3:
                return LONG;
            default:
                throw new IllegalArgumentException("Invalid type:" + type);
        }

    }
}