What is the use of ResultSet?

What is the use of ResultSet? A ResultSet is a Java object that contains the results of executing an SQL query. In other words, it contains the rows that satisfy the conditions of the query. The data stored in a ResultSet object is retrieved through a set of get methods that allows access to the various columns of the current row.

What is the use of ResultSet in case of JDBC? It is used to store the data which are returned from the database table after the execution of the SQL statements in the Java Program. The object of ResultSet maintains cursor point at the result data.

What do you mean by ResultSet? An SQL result set is a set of rows from a database, as well as metadata about the query such as the column names, and the types and sizes of each column. Depending on the database system, the number of rows in the result set may or may not be known. A result set is effectively a table.

What are the type of ResultSet in JDBC? Explanation: JDBC provides only two types of ResultSets: Forward and Scrollable ResultSet.

How do I know if a ResultSet is empty? The JDBC ResultSet doesn’t provide any isEmpty(), length() or size() method to check if its empty or not. Hence, when a Java programmer needs to determine if ResultSet is empty or not, it just calls the next() method and if next() return false it means ResultSet is empty.

What is the use of ResultSet? – Additional Questions

How do I know if a ResultSet is closed?

The ResultSet object contains a cursor/pointer which points to the current row. Initially this cursor is positioned before first row (default position). The isClosed() method of the ResultSet interface is used to determine whether the current ResultSet object is closed.

What is ResultSet next in Java?

The next() method of the ResultSet interface moves the pointer of the current (ResultSet) object to the next row, from the current position. Statement stmt = con. createStatement(); ResultSet rs = stmt. And on calling the next() method for the second time the result set cursor will be moved to the 2nd row.

What is the meaning of ResultSet Type_scroll_insensitive?

TYPE_SCROLL_INSENSITIVE means that the ResultSet can be navigated (scrolled) both forward and backwards. You can also jump to a position relative to the current position, or jump to an absolute position. The ResultSet is insensitive to changes in the underlying data source while the ResultSet is open.

What is scrollable ResultSet?

JDBC provides two types of result sets that allow you to scroll in either direction or to move the cursor to a particular row. Derby supports one of these types: scrollable insensitive result sets ( ResultSet. TYPE_SCROLL_INSENSITIVE ). When you use a result set of type of type ResultSet.

Are ResultSet updatable?

Whenever we create a ResultSet object that never allows us to update the database through the ResultSet object, it allows retrieving the data only forward. Such type of ResultSet is known as non-updatable and non-scrollable ResultSet.

What happens if you call deleteRow () on a ResultSet object?

What happens if you call deleteRow() on a ResultSet object? The row you are positioned on is deleted from the ResultSet, but not from the database.

What does JDBC stand for?

The Java Database Connectivity (JDBC) API provides universal data access from the Java programming language. Using the JDBC API, you can access virtually any data source, from relational databases to spreadsheets and flat files.

What is ResultSet explain with example?

A ResultSet object maintains a cursor that points to the current row in the result set. The term “result set” refers to the row and column data contained in a ResultSet object. The methods of the ResultSet interface can be broken down into three categories − Navigational methods − Used to move the cursor around.

What is updatable ResultSet?

An updatable ResultSet object allows us to update a column value, insert column values and delete a row. Here the code snippet that makes a scrollable and updatable result set object. PreparedStatement stmt = conn. prepareStatement(sql, ResultSet.

Can a ResultSet be null?

No, ResultSet returned by executeQuery(java. lang. String) method can never be null. Moreover, the standard way to check whether a ResultSet is empty or not is to try setting its cursor to first row by using its first() and if it returns false it indicates that ResultSet is empty.

How do I know the size of my ResultSet?

println(“Total number of rows in ResultSet object = “+rowCount); Simply iterate on ResultSet object and increment rowCount to obtain size of ResultSet object in java. rowCount = rs. getRow();

How do you find the values of a ResultSet?

The “check for any results” call ResultSet. next() moves the cursor to the first row, so use the do {} while() syntax to process that row while continuing to process remaining rows returned by the loop. This way you get to check for any results, while at the same time also processing any results returned.

Should ResultSet be closed?

You should explicitly close Statements , ResultSets , and Connections when you no longer need them, unless you declare them in a try -with-resources statement (available in JDK 7 and after). Connections to Derby are resources external to an application, and the garbage collector will not close them automatically.

What happens if prepared statement is not closed?

What happens if prepared statement is not closed?

Can we use two ResultSet in Java?

Stored procedures contain IN and OUT parameters or both. They may return result sets in case you use SELECT statements. Stored procedures can return multiple result sets.

Can we return ResultSet in Java?

Yes, just like any other objects in Java we can pass a ResultSet object as a parameter to a method and, return it from a method. The main method invokes the retrieveData() method and prints the contents of the obtained ResultSet.

What is use of isFirst () method?

This isFirst method is specified by the isFirst method in the java. sql. ResultSet interface. If this method is used with forward and dynamic cursors, an exception is thrown.

What is Type_scroll_insensitive?

TYPE_SCROLL_INSENSITIVE. The constant indicating the type for a ResultSet object that is scrollable but generally not sensitive to changes to the data that underlies the ResultSet .

What is CallableStatement correct?

Q 4 – Which of the following is correct about CallableStatement? A – Used when you want to access the database stored procedures. B – The CallableStatement interface can accept runtime input parameters.

What is scrollable ResultSet in hibernate?

ScrollableResults is like a cursor . An important feature of ScrollableResults is that it allows accessing ith object in the current row of results, without initializing any other results in the row through get(int i) function. It also allows moving back and forth the result set using next() and previous() function.

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