Java 结果集中没有数据
我有以下代码:Java 结果集中没有数据,java,resultset,Java,Resultset,我有以下代码: string query = select COUNT(*) from TRACKER where TYPE = ? and LAST_MODIFIED_TIME > LAST_RETREIVED_TIME; prepStmt = connection.prepareStatement(query); prepStmt.setString(1, "xml"); resultset = prepStmt.executeQue
string query = select COUNT(*) from TRACKER where TYPE = ? and LAST_MODIFIED_TIME > LAST_RETREIVED_TIME;
prepStmt = connection.prepareStatement(query);
prepStmt.setString(1, "xml");
resultset = prepStmt.executeQuery();
resultset.next();
int rowcount = resultset.getInt("COUNT(*)");
在数据库中,我有1行用于上面的查询,但在代码中,我得到rowcount=0。
有什么帮助吗?尝试为
计数(*)提供一个别名。
:
见db是oracle。我在那里进行了检查,得到1作为输出,为您的
COUNT(*)
列提供别名,然后进行检查<代码>从中选择计数(*)res代码>并使用introwcount=resultset.getInt(“res”)代码>
String query = "select COUNT(*) as count from TRACKER where TYPE = ?"+
" and LAST_MODIFIED_TIME > LAST_RETREIVED_TIME";
prepStmt = connection.prepareStatement(query);
prepStmt.setString(1, "xml");
resultset = prepStmt.executeQuery();
resultset.next();
int rowcount = resultset.getInt("count");