In the last article, I have shown you how to convert Date to Timestamp in Java and today we'll learn about converting timestamp value from database to Date in Java. As you remember, the JDBC API uses separate Date, Time, and Timestamp classes to confirm DATE, TIME, and DATETIME data type from the database, but most of the Java object-oriented code is written in java.util.Date. This means you need to know how to convert the timestamp to date and vice-versa. You can do by using the getTime() method, which returns the number of millisecond from Epoch value.
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JDBC - How to Convert java.sql.Date to java.util.Date in Java with Example
How to convert java.sql.Date into a java.util.Date and vice-versa is a popular JDBC interview question which is also asked a follow-up question of the difference between java.sql.Date and java.util.The date which we have seen in our last article. Since both SQL date and Util date store values as a long millisecond, converting them back and forth is easy. Both java.sql.Date and java.util.The date provides a convenient method called getTime() which returns a long millisecond equivalent of a wrapped date value. Here is a quick example of converting java.util.Date to java.sql.Date and then back to util Date.
JDBC - How to get Row and Column Count From ResultSet in Java? Example
One of the common problems in JDBC is that there is no way to get the total number of records returned by an SQL query. When you execute a Statement, PreparedStatement, or CallableStatement using execute()or executeQuery() they return ResultSet and it doesn't have any method to return the total number of records it is holding. The only way to find the total number of records is to keep the count while you are iterating over ResultSet while fetching the result. This way, you can print the total number of rows returned the SQL query but only after you have processed all records and not before, which may not be the right way and incur significant performance cost if the query returns a large number of rows.
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