Seems like there's probably a unit test that does a join in MySQL. Maybe looking at that code will help. I got a join working in SQLite with DbLinq, which doesn't help you a lot, but it's something.
On Tue, Apr 7, 2009 at 8:14 AM, <[email protected]> wrote: > > Hello NewsGroup, > > I have created a little example with the Join Operator. But I'm a > newbie in LinQ, so I dont know if its my fault. > I have two tables: hotel and guest. In guest is a foreign key to > hotel. Now I want to make a Join in VB: > > Dim HotelJoin = From Hotel In oDb.Hotel Join Guest In oDb.Guest On > Hotel.ID Equals Guest.HotelID > > But it does not work. The HotelJoin.First() function throws an > exception 1010. Does somebody know what I'm doing wrong? > > > Regards > > Mike > PS: I have attached a SQL Script for creating the database and the VB > Function for verifying the error. > > > > ######################################################################################## > #### This SQL script creates one database (tourist) and two tables > (hotel and guest) in a MySQL DB: > CREATE SCHEMA IF NOT EXISTS `Tourist` DEFAULT CHARACTER SET latin1 > COLLATE latin1_german1_ci ; > USE `Tourist`; > > -- ----------------------------------------------------- > -- Table `Tourist`.`Hotel` > -- ----------------------------------------------------- > DROP TABLE IF EXISTS `Tourist`.`Hotel` ; > > CREATE TABLE IF NOT EXISTS `Tourist`.`Hotel` ( > `ID` INT UNSIGNED NOT NULL AUTO_INCREMENT , > `HotelName` VARCHAR(45) NOT NULL , > PRIMARY KEY (`ID`) ) > ENGINE = InnoDB > COMMENT = '<double-click to overwrite multiple objects>'; > > > -- ----------------------------------------------------- > -- Table `Tourist`.`Guest` > -- ----------------------------------------------------- > DROP TABLE IF EXISTS `Tourist`.`Guest` ; > > CREATE TABLE IF NOT EXISTS `Tourist`.`Guest` ( > `ID` INT UNSIGNED NOT NULL AUTO_INCREMENT , > `GuestName` VARCHAR(50) NULL , > `Hotel_ID` INT UNSIGNED NOT NULL , > PRIMARY KEY (`ID`) , > INDEX `fk_Gast_Hotel` (`Hotel_ID` ASC) , > CONSTRAINT `fk_Gast_Hotel` > FOREIGN KEY (`Hotel_ID` ) > REFERENCES `Tourist`.`Hotel` (`ID` ) > ON DELETE NO ACTION > ON UPDATE NO ACTION) > ENGINE = InnoDB > > ######################################################################################## > > > ######################################################################################## > #### Try this function to test the join: > Sub Main() > > Dim sBogenDbConnInfo As String = "server=127.0.0.1;user id=root; > password=root; database=Tourist" > Dim oDb As TouristLinq.Tourist = New TouristLinq.Tourist(New > MySql.Data.MySqlClient.MySqlConnection(sBogenDbConnInfo)) > > Dim HotelJoin = From Hotel In oDb.Hotel _ > Join Guest In oDb.Guest _ > On Hotel.ID Equals Guest.HotelID > ' HotelJoin is empty? But I have inserted matching entries in > table hotel and guest? > Dim Row1 = HotelJoin.First() ' Here I get the exception 1010 > > Dim o = From HotelList In oDb.Hotel ' Here I get my one and only > hotel row > Dim p = From GuestList In oDb.Guest ' In p is the Guest saved. All > ID's are 1, so the values fit. > > End Sub > > ######################################################################################## > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "DbLinq" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/dblinq?hl=en -~----------~----~----~----~------~----~------~--~---
