resultset

问题 What is the difference between ResultSetMetaData.getColumnLabel and ResultSetMetaData.getColumnName? Label: Gets the designated column's suggested title for use in printouts and displays. Name: Get the designated column's name. Does anyone know how Label is determined? 回答1: String getColumnLabel(int column) throws SQLException; If a SQL AS is not specified, the value returned from getColumnLabel will be the same as the value returned by the getColumnName method. Example: select id as user_no

问题 How can I write a stored procedure that contains a dynamically built SQL statement that returns a result set? Here is my sample code: CREATE OR REPLACE FUNCTION reporting.report_get_countries_new ( starts_with varchar, ends_with varchar ) RETURNS TABLE ( country_id integer, country_name varchar ) AS $body$ DECLARE starts_with ALIAS FOR $1; ends_with ALIAS FOR $2; sql VARCHAR; BEGIN sql = 'SELECT * FROM lookups.countries WHERE lookups.countries.country_name >= ' || starts_with ; IF ends_with

问题 I want to mock a ResultSet. Seriously. I'm refactoring one big complicated piece of code which is parsing data from ResultSet, and I want my code to behave identically. So, I need to write a unit test for the piece being refactored to be able to test this. After googling I came up with 2 ideas: Use EasyMock, write looooong mocking sequence. VERY BAD solution: hard to add initial data, hard to change data, big test debugging promices. Use Apache Derby or HSQLDB to create in-memory DB, fill it

问题 I'm doing a query to retrieve a large amount of IDs (integers). Instead of iterating millions of times through the ResultSet and copying everything one-by-one to an ArrayList, is there some way to simply retrieve everything as an ArrayList? I understand that ResultSet is supposed to be iterated because the underlying implementation may be caching stuff, but in my situation I just need all the IDs straight away. I know I can set the FetchSize to a large number, but then I still have to

问题 i know this should be simpel and im probably staring straight at the problem but once again im stuck and need the help of the code gurus. im trying too take one row from a column in jdbc, and put them in an array. i do this as follows: public void fillContactList() { createConnection(); try { Statement stmt = conn.createStatement(); ResultSet namesList = stmt.executeQuery("SELECT name FROM Users"); try { while (namesList.next()) { contactListNames[1] = namesList.getString(1); System.out

问题 I'm using JDBC for very simple database connectivity. I have created my connection/statement and executed a query. I check the query object of the statement in the debugger to confirm that it is sending a proper query. I then double checked the query (copied straight from debugger) on the database to make sure it returns data. The returned resultset, however, gives false on .next() Are there any common pitfalls here that I'm missing? public List<InterestGroup> getGroups() { myDB.sendQuery(

问题 I keep getting this whenever I try to use this method. java.sql.SQLException: Operation not allowed after ResultSet closed at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1055) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:956) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:926) at com.mysql.jdbc.ResultSetImpl.checkClosed(ResultSetImpl.java:794) at com.mysql.jdbc.ResultSetImpl.next(ResultSetImpl.java:7077) at server.util.Plimus$1.run(Plimus.java:77) This

问题 I'm having a really bad time with a ResultSet, which is closed within a while-Loop for iterating this ResultSet. I have know the exact line in which the ResultSet is closed, but i have no idea why. public LinkedList<Athlet> alleAbrufen () throws SQLException { LinkedList<Athlet> alleAthleten = new LinkedList<Athlet>(); String abrufenAthleten = "SELECT * FROM Athlet ORDER BY athlet_id"; ResultSet athleten_rs = stmt.executeQuery(abrufenAthleten); while (athleten_rs.next()) { long id = athleten

问题 I am losing precision in my ResultSet.getDate(x) calls. Basically: rs = ps.executeQuery(); rs.getDate("MODIFIED"); is returning dates truncated to the day where MODIFIED is an Oracle TIMESTAMP field of default precision. I think there may be some JDBC tweak I'm missing; usually TIMESTAMP is compatible with DATE, but I'm hoping I don't have to redefine the entire table. 回答1: ResultSet.getDate() returns a java. sql .Date , not a java. util .Date . It is defined to be a timeless date. If you