ms-access

问题 I have tried to create three tables(CUSTOMERS, VEHICLES and RENTALS), the third table (RENTALS) has foreign keys referring to the two primary keys of the first two tables (CUSTOMERS and RENTALS). When creating this third table I get an error Missing columns in relationship(Rel=CUSTOMERS[[]] -> RENTALS[[]]) Here's my codes private void createTables() throws SQLException { Statement statement = conn.createStatement(); statement.executeUpdate("CREATE TABLE CUSTOMERS(custNumber AUTOINCREMENT

问题 I am trying to export a lot of large tables from a MS Access db with java using the jdbc:odbc bridge. I wanted to save these tables to a CSV file first was wondering what would the best way to do this would be? any help would be appreciated. 回答1: Fetch the values and write a standard text file line by line separating the values. I#m sure there are some libs for this purpose try { FileWriter writer = new FileWriter("c:\\temp\\MyFile.csv"); while(result.next()) { for(int i = 0; i < columnSize;

问题 ResultSet rs; PreparedStatement ps; Connection con; public Attribute() { try{ con = DriverManager.getConnection("jdbc:ucanaccess://D:/programming/myassignment/Database1.accdb"); System.out.println("Java is now connected to database"); }catch(Exception ex){ System.out.println(ex); } JButton btnAdd = new JButton("Add"); btnAdd.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { try{ PreparedStatement pstmt = (PreparedStatement) con.prepareStatement("insert into

问题 ResultSet rs; PreparedStatement ps; Connection con; public Attribute() { try{ con = DriverManager.getConnection("jdbc:ucanaccess://D:/programming/myassignment/Database1.accdb"); System.out.println("Java is now connected to database"); }catch(Exception ex){ System.out.println(ex); } JButton btnAdd = new JButton("Add"); btnAdd.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { try{ PreparedStatement pstmt = (PreparedStatement) con.prepareStatement("insert into

问题 I have tried many different things to pull the data from Access and put it into a neat data frame. right now my code looks like this. from pandas import DataFrame import numpy as np import pyodbc from sqlalchemy import create_engine db_file = r'C:\Users\username\file.accdb' user = 'user' password = 'pw' odbc_conn_str = 'DRIVER={Microsoft Access Driver (*.mdb, *.accdb)};DBQ=%s;UID=%s;PWD=%s' % (db_file, user, password) conn = pyodbc.connect(odbc_conn_str) cur = conn.cursor() qry = cur.execute(

问题 I am using an Access DB to keep track of Utility Usage on hundreds of accounts. The meters in these accounts have consumption values only per month. I need to take the consumption value of this month and subtract it from the value of the previous month. to get the consumption for this month. I know that in SQL Server, there is a lead/lag function that can calculate those differences. Is there a similar function in access? or is there a simple way to subtract the value in one row from the one

问题 I am having problems running a query without either truncating the note field in NotesTbl or returning repeated entries. UID is not unique for AccessTbl. When I leave out "distinct" notes will return multiple times because I am joining with AccessTbl on a non-distinct condition. When I use distict, the note field is trunctated because it is a memo field. Here is my query: SELECT DISTINCT NotesTbl.pin, NotesTbl.noteid, NotesTbl.note, NotesTbl.date, AccessTbl.affiliation, AccessTbl.name FROM

问题 I have been searching for a way to extract images from access forms. A search on Google will nearly always point to OLEtoDisk. This software allows to export images stored in OLE fields inside access tables. This is not what I want. I have a form with some logos, headers and background images. Those images are making the database become bigger and bigger (because they are embedded in the form). I would extract them, place them on our server together with the back-end file and add them back to

问题 I am trying to load some data into R from an Access database. All of the instructions I can find say to use odbcConnectAccess("file.mdb") but I cannot seem to load this function. Has it been replaced or renamed? Is there another way to do this? I've loaded RODBC with library("RODBC") but still have no luck. Thank you! 回答1: If you're using on a Mac, I've found success using Actual Technologies drivers to connect to Access databases. If you've already set up the ODBC connection, using ODBC

问题 I've been using VBA to examine all the queries, forms, and modules in my Access 2000 database, but it can be quite tedious and slow. Recently, I decided to take a closer look at the system tables in Access, in particular, MSysQueries and MSysObjects. Can I use these tables to examine my objects in the database faster? Of course, these tables are read-only, so I can't make any modifications to the database through them without returning to VBA. What do the attributes in MSysQueries mean? 回答1: