These methods perform equijoins, or joins that match two data sources based on equality of their keys.

The join methods provided in the LINQ framework are Join and GroupJoin. If you have a list of Department objects and you want to find all the students in each department, you could use a join operation to find them.

An example of a one-way relationship is a Student class that has a property of type Department that represents the major, but the Department class doesn't have a property that is a collection of Student objects. In object-oriented programming, joining could mean a correlation between objects that isn't modeled, such as the backwards direction of a one-way relationship. Joining is an important operation in queries that target data sources whose relationships to each other can't be followed directly. Both return the same results in this example.A join of two data sources is the association of objects in one data source with objects that share a common attribute in another data source.

X = x + 'story: ' + rs.Column('story_name').StringValue + ' character: ' + rs.Column('character_name').StringValue + EndOfLineĮdit: I originally used left join out of habit. Rs = db.SelectSQL(sql, 'A Christmas Carol') 'inner join characters b on b.fkstory = a.id ' +_ 'select story and associated characters if the story name is A Christmas Carol Sql = 'insert into characters(id, fkstory, character_name) values (?, ?, ?)' Sql = 'insert into stories(id, story_name) values (?, ?)'ĭb.ExecuteSQL(sql, 1, 'A Christmas Carol')ĭb.ExecuteSQL(sql, 2, 'A Halloween Tale') Sql = 'create table characters(id integer, fkstory integer, character_name text)' Sql = 'create table stories(id integer, story_name text)' If you’re looking for a story and all the characters associated with it, this simplified example might help illustrate: var db as new SQLiteDatabase So why is this code working correctly in the DB Browser for Sqlite program, but not in Xojo? But I figured I want to get this part to work first. Of course that last part should be changed I don’t want to add the Story title in the code, but select a story from the StoriesListbox instead.

Running the app shows me ALL the characters from ALL the stories in the database, not only from '‘A Christmas Carol’. I placed this code in the ListBoxCharacters. I cannot get this in Xojo to work though. The results are correct, only the characters belonging to the story title that I added at the end (‘A Christmas Carol’) are shown. SELECT * FROM characters INNER JOIN Stories on Stories.ID = Characters.FKStory WHERE stories.Story_title = 'A Christmas Carol' I studied the info in the Database basics for beginners - Xojo documentation page and came up with this code that works in the “DB Browser for Sqlite” Execute Sqlite tab: The goal is after selecting a Story title in the Stories listbox, only see the Characters that belong to that story in the Characters Listbox. One table is called Stories and contains story information and the other table is called Characters and contains character information, this table has a field the refers to the ID field in the Stories table. For weeks I am trying to get an inner Join between 2 tables to work.

Db browser for sqlite inner join