What is ResultSet in Java with example?
A ResultSet object is a table of data representing a database result set, which is usually generated by executing a statement that queries the database. For example, the CoffeeTables. viewTable method creates a ResultSet , rs , when it executes the query through the Statement object, stmt .
How do you count ResultSet in Java?
You can get the column count in a table using the getColumnCount() method of the ResultSetMetaData interface. On invoking, this method returns an integer representing the number of columns in the table in the current ResultSet object.
How does ResultSet work in Java?
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.
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.
What are the types of ResultSet?
There are two types of result sets namely, forward only and, bidirectional. Forward only ResultSet: The ResultSet object whose cursor moves only in one direction is known as forward only ResultSet. By default, JDBC result sets are forward-only result sets.
How do you size a ResultSet?
Simply iterate on ResultSet object and increment rowCount to obtain size of ResultSet object in java. rowCount = rs. getRow();
How do you create a ResultSet object?
For each table or view in the database, create a Java class with properties equivalent to the table’s columns. Load the tables contents into a ResultSet object. Using while(ResultSet. next()) to iterate through the ResultSet, create a new object (from the class) in step 1 for each item in the ResultSet.
Can ResultSet be null in Java?
The wasNull() method of the ResultSet interface determines whether the last column read had a Null value. i.e. whenever you read the contents of a column of the ResultSet using the getter methods (getInt(), getString etc…) you can determine whether it (column) contains null values, using the wasNull() method.
What is ResultSet ResultSet types?
The java. sql. ResultSet interface represents the result set of a database query. 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.
How do I count rows in ResultSet?
Getting the number of rows using methods The last() method of the ResultSet interface moves the cursor to the last row of the ResultSet and, the getRow() method returns the index/position of the current row.
Why is ResultSet empty?
Hence, when a Java programmer needs to determine if ResultSet is empty or not, it just calls the next() method and if next() returns false it means ResultSet is empty.
How do I find the first record in ResultSet?
The ResultSet object contains a cursor/pointer which points to the current row. Initially this cursor is positioned before first row (default position). You can move the cursor of the ResultSet object to the first row from the current position, using the first() method of the ResultSet interface.
How do I find the number of columns in a ResultSet?
What are the different types of ResultSet?