What happens if we call ResultSet getInt 0?
getInt(0) when Select query result just have one column of integer type? Answer: This is one of the tricky Java question which comes from JDBC. you may think that it will return the first column as an integer from the Query result set but unfortunately, it doesn’t.
How do I get my ResultSet first record?
You can use absolute to navigate to the first row: ResultSet rs = …; rs. absolute(1); // Navigate to first row int id = rs. getInt(“id”); …
How do you check 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() returns false it means ResultSet is empty.
How do I get a complete row from a ResultSet?
The getRow() method of the ResultSet interface retrieves the current row number/position of the ResultSet pointer. This method returns an integer value representing the current row number to which the ResultSet pointer points to.
Can ResultSet return null?
Initially this cursor is positioned before first row. The wasNull() method of the ResultSet interface determines whether the last column read had a Null value. If there are null values in the column this method returns true, else it returns false.
What happens if you call deleteRow on a ResultSet object?
What happens if you call deleteRow() on a ResultSet object? a. The row you are positioned on is deleted from the ResultSet, but not from the database.
Which packages contain the JDBC classes?
Which packages contain the JDBC classes
- java.jdbc and javax.jdbc.
- java.jdbc and java.jdbc.sql.
- ✅ java.sql and javax.sql.
- java.rdb and javax.rdb.
Can a ResultSet be null?
Yes. No, ResultSet returned by executeQuery(java. lang. String) method can never be null.
Is before first Java?
The beforeFirst() method of the ResultSet interface moves the pointer of the current (ResultSet) object to the default position (before first), from the current position. Statement stmt = con. createStatement(); ResultSet rs = stmt.
What happens if you call the method close () on a ResultSet object?
Calling the method close on a Statement object that is already closed has no effect. Releases this ResultSet object’s database and JDBC resources immediately instead of waiting for this to happen when it is automatically closed.
Can ExecuteQuery return null?
ExecuteQuery returns null while execute statement returns true.
How to move the cursor to the first row in resultset?
Initially this cursor is positioned before first row. The next () method of the ResultSet interface moves the pointer of the current (ResultSet) object to the next row, from the current position. i.e., on calling the next () method for the first time the result set pointer/cursor will be moved to the 1st row (from default position).
How to retrieve column values from the current row in resultset?
The ResultSet interface provides getter methods (getBoolean, getLong, and so on) for retrieving column values from the current row. Values can be retrieved using either the index number of the column or the name of the column. In general, using the column index will be more efficient. Columns are numbered from 1.
What are resultset and resultsetmetadata?
Here, we will learn about JDBC ResultSet, ResultSetMetaData, and DatabaseMetaData interfaces, their methods and how to use the methods in Java program. ResultSet Interface is present in the java.sql package. 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.
How to find the row count of a result set?
Iterating through the result set to find the row count is almost same as processing the data. It is better to do another count(*) query instead. On some database systems it can be very slow to do a select count(*) query, so maybe the TS should find a way to remove the need to know the size of the resultset at all.