java.util.Date vs java.sql.Date

Many java developers may have this question ‘java.util.Date is there to represent date, why again java.sql.Date class is given by Java?’ in mind. In this post, I am going to address this question.

Before answering this question, let’s try to understand how sql handle the date and time.

SQL support following data types for storing a date or a date/time value.

Data Type	Format
DATE	YYYY-MM-DD
DATETIME	YYYY-MM-DD HH:MI:SS
TIMESTAMP	YYYY-MM-DD HH:MI:SS
YEAR	YYYY or YY

As you see, DATE type, it stores only year, month and day. It  do not store the time (like hour, minute, second). But in case of ‘java.util.Date’, it stores the time also. To address this issue, java.sql.Date come into picture. It maintains the semantics with respect to DATE type of SQL.

Let’s see it with an example.

Application.java

package com.sample.app;

public class Application {

 public static void main(String args[]) {
  java.util.Date today = new java.util.Date();
  
  java.sql.Date sqlDate = new java.sql.Date(today.getTime());
  java.util.Date utilDate = new java.util.Date(today.getTime());

  System.out.println("Sql Date : " + sqlDate);
  System.out.println("Util Date : " + utilDate);
 }
}

Output

Sql Date : 2018-09-16
Util Date : Sun Sep 16 10:40:07 IST 2018

Note: java.sql.Date is a sub class of java.util.Date.

Below table summarizes the SQL date related types and corresponding mapping classes provided by java.

SQL Type	Java Class
DATE	java.sql.Date
TIME	java.sql.Time
TIMESTAMP	java.sql.Timestamp

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