Convert a Result Set from SQL Array to Array of Strings
Use: Array a = rs.getArray(“is_nullable”); String[] nullable = (String[])a.getArray(); As explained here Array is SQL type, getArray() returns an object to cast to java array.
resultset
Treating an SQL ResultSet like a Scala Stream
I didn’t test it, but why wouldn’t it work? new Iterator[String] { def hasNext = resultSet.next() def next() = resultSet.getString(1) }.toStream
How do I get the row count in JDBC?
You’re going to have to do this as a separate query, for example: SELECT COUNT(1) FROM table_name Some JDBC drivers might tell you but this is optional behaviour and, more to the point, the driver may not know yet. This can be due to how the query is optimised eg two example execution strategies in … Read more
How to get the number of columns from a JDBC ResultSet?
You can get columns number from ResultSetMetaData: Statement st = conn.createStatement(); ResultSet rs = st.executeQuery(query); ResultSetMetaData rsmd = rs.getMetaData(); int columnsNumber = rsmd.getColumnCount();
ResultSet: Exception: set type is TYPE_FORWARD_ONLY — why?
Change your first statement to this pstat=con.prepareStatement(“select typeid from users where username=? and password=?”, ResultSet.TYPE_SCROLL_SENSITIVE, ResultSet.CONCUR_UPDATABLE); This way you can move forward and backward, so less things to worry about
How to get row count using ResultSet in Java?
If you have access to the prepared statement that results in this resultset, you can use connection.prepareStatement(sql, ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY); This prepares your statement in a way that you can rewind the cursor. This is also documented in the ResultSet Javadoc In general, however, forwarding and rewinding cursors may be quite inefficient for large result sets. … Read more
ResultSet.getString(1) throws java.sql.SQLException: Invalid operation at current cursor position
You should use the next statement first. ResultSet set = statement.executeQuery(); if (set.next()) { userName = set.getString(1); //your logic… } UPDATE As the Java 6 Documentation says A ResultSet cursor is initially positioned before the first row; the first call to the method next makes the first row the current row; the second call makes … Read more
Create a comma-separated string from a single column of an array of objects
Better: $resultstr = array(); foreach ($results as $result) { $resultstr[] = $result->name; } echo implode(“,”,$resultstr);
Bulk insert in Java using prepared statements batch update
I’ll address your questions in turn. Will the executeBatch method tries to send all the data at once? This can vary with each JDBC driver, but the few I’ve studied will iterate over each batch entry and send the arguments together with the prepared statement handle each time to the database for execution. That is, … Read more
Get Number of Rows returned by ResultSet in Java
First, you should create Statement which can be move cursor by command: Statement stmt = con.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY); Then retrieve the ResultSet as below: ResultSet rs = stmt.executeQuery(…); Move cursor to the latest row and get it: if (rs.last()) { int rows = rs.getRow(); // Move to beginning rs.beforeFirst(); … } Then rows variable will contains … Read more