resultset

Joining multiple result set

由 人走茶凉 提交于 2019-12-11 12:48:09
问题 I am trying to develop a Java application which merges data from multiple data source basically RDBMS. The scenario is some thing like this. I have creates a connection to two data sources, lets say a MSSQL database and other Oracle. Also on each connection a user can create a DataObject( a Java object) which contains a SQL query and a connection. The query is executed on the connection and result are displayed. Now what I want is that my user can join and filter result obtained from multiple

java nested while loop in result set

由 醉酒当歌 提交于 2019-12-11 12:46:39
问题 I want to merge results from 2 resultSet which are results returned from sql queries. What is the best way to accomplish this? My plan is lopping over 2 result sets to print out the final result from both result sets. Both results set have the same id column which are their first column. But for the inner while loop, I only get the first value printed out. I thought when there is a match, it prints the value from the second result set, and break out of the loop. Then when there is another

面向对象 (13)数据库访问

由 陌路散爱 提交于 2019-12-11 12:31:31
题目1： 编写一个应用程序，输入用户名和密码，访问test数据库中t_login表（字段包括id、username、password），验证登录是否成功。 一、源程序 /**访问数据库 进行查询 * 1个类1个方法 */ package cn.edu.ccut.w1210; import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; import java.util.Scanner; public class Test { public static void main(String[] args) { Scanner reader = new Scanner(System.in); System.out.print("请输入用户名和密码\n"); String username= reader.nextLine(); String password= reader.nextLine(); try { Class.forName("com.mysql.jdbc.Driver");/

Fetching single row result without iterating in loop from Mysql using Java

由 与世无争的帅哥 提交于 2019-12-11 11:04:33
问题 I have a simple query that returns only count of rows. select count(*) cnt from table I can read it by iterating through resultset. like while(rs.next()){ int rowCount= rs.getInt(cnt); } But is there any way,using which I can get count directly without looping. 回答1: How about: int rowCount = rs.next() ? rs.getInt(cnt) : -1; It doesn't save you much though 来源： https://stackoverflow.com/questions/21476777/fetching-single-row-result-without-iterating-in-loop-from-mysql-using-java

how to return an object (from a MySQL temporary table) into a Coldfusion stored procedure?

由 孤人 提交于 2019-12-11 08:58:56
问题 I'm calling stored procedure in Coldfusion8/MySQL which gets 3 types of min and max prices from products table. I'm having problems returning the temp table back to MySQL. The below code only returns the first foundMin value and not the temp table itself. If I run this inside MySQL the results are foundmin 1st price > returned to Coldfusion foundmax 1st price foundmin 2nd price foundmax 2nd price foundmin 3rd price foundmax 3rd price temporary table So I'm returning all individual table

Trying to query database using PreparedStatement, ResultSet is coming back closed when it ought not to

由 不想你离开。 提交于 2019-12-11 08:43:52
问题 I am trying to query my database using a prepared statement. Initially, I had this: public ResultSet preparedQueryContactsWhereAccount(String accountName) throws SQLException { PreparedStatement statment = null; ResultSet rs = null; String statString = "SELECT * FROM contacts WHERE account_name = ?"; try { statment = mConn.prepareStatement(statString); statment.setString(1, accountName); rs = statment.executeQuery(); } catch(SQLException e) { e.printStackTrace(); } if(statment != null) {

scala - Resultset to spark Dataframe

由 我怕爱的太早我们不能终老 提交于 2019-12-11 07:59:11
问题 i am querying mysql table val url = "jdbc:mysql://XXX-XX-XXX-XX-XX.compute-1.amazonaws.com:3306/pg_partner" val driver = "com.mysql.jdbc.Driver" val username = "XXX" val password = "XXX" var connection:Connection = DriverManager.getConnection(url, username, password) val statement = connection.createStatement() val patnerName = statement.executeQuery("SELECT id,name FROM partner") i do get my result in patnerName but i need to be converted to Dataframe. i am able to print data by below code:

java.lang.NullPointerException in CreateNamedQuery

由 放肆的年华 提交于 2019-12-11 07:57:26
问题 I have the following code which is resulting in a java.lang.NullPointerException : List results = em.createNamedQuery("User.findByUserName").setParameter("userName", username).getResultList(); User is the entity bean, which contains: @NamedQuery(name = "User.findByUserName", query = "SELECT u FROM User u WHERE u.userName = :userName"), Does anyone know why? 回答1: A method getResultList() doesn't throw NullPointerException (it returns empty list if there's no match), so I'm guessing that it

How to check if resultset has records returned w/o moving the cursor in Java

由 有些话、适合烂在心里 提交于 2019-12-11 07:39:52
问题 I am wondering how to check if the resultset has some records returned, just like below, while(((ResultSet) rs).next()){ ((ResultSet) rs).previous(); return true; } But I can't do this since the result set type is TYPE_FORWARD_ONLY, is there any handy API available for my case? wasNull is not the right one for certain, thank you for any pointers! Even 回答1: if(!resultSet.isBeforeFirst()){ System.out.println("resultset contin no rows"); } isBeforeFirst() returns true if the cursor is before the

How i can put a result set from a stored procedure in a temporary table in DB2

由 此生再无相见时 提交于 2019-12-11 07:02:11
问题 The title is very descriptive i think... My scenario is the next. I need to put the result of a result set (for example a result set with 6 columns and variable rows) from a stored procedure in some temporary table to make some operations over this new table. I find some examples in the web but nothing in DB2... The big problem is how to populate that new table with the restult set of a called stored procedure 回答1: DECLARE GLOBAL TEMPORARY TABLE probably accomplishes what you want. You can
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