Module: E2Model::DatasetMethods

Defined in:
lib/engine2/core.rb

Instance Method Summary collapse

Instance Method Details

#ensure_primary_key ⇒ Object

Raises:



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# File 'lib/engine2/core.rb', line 286

def ensure_primary_key
    pk = @model.primary_keys
    raise Engine2::E2Error.new("No primary key defined for model #{model}") unless pk && pk.all?

    if opts_select = @opts[:select]
        sel_pk = []
        opts_select.each do |sel|
            name = case sel
                when Symbol
                    sel.to_s =~ /\w+__(\w+)/ ? $1.to_sym : sel
                when Sequel::SQL::QualifiedIdentifier
                    sel.column
                when Sequel::SQL::AliasedExpression
                    sel
                    # nil #sel.aliaz # ?
                    # sel.expression
                end
            sel_pk << name if name && pk.include?(name)
        end

        if pk.length == sel_pk.length
            self
        else
            sels = (pk - sel_pk).map{|k| k.qualify(@model.table_name)}
            select_more(*sels)
        end
    else
        select(*pk.map{|k| k.qualify(@model.table_name)})
    end

end

#extract_select(sel, al = nil, &blk) ⇒ Object 



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# File 'lib/engine2/core.rb', line 386

def extract_select sel, al = nil, &blk
    case sel
    when Symbol
        if sel.to_s =~ /^(\w+)__(\w+?)(?:___(\w+))?$/
            yield $1.to_sym, $2.to_sym, $3 ? $3.to_sym : nil
        else
            yield nil, sel, al
        end
    when Sequel::SQL::QualifiedIdentifier
        yield sel.table, sel.column, al
    when Sequel::SQL::AliasedExpression
        sel
        # extract_select sel.expression, sel.aliaz, &blk
        # expr = sel.expression
        # yield  expr.table, expr.column
    else
        raise Engine2::E2Error.new("Unknown selection #{sel}")
    end
end

#get_opts ⇒ Object 



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# File 'lib/engine2/core.rb', line 406

def get_opts
    @opts
end

#setup!(fields) ⇒ Object 



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# File 'lib/engine2/core.rb', line 318

def setup! fields
    joins = {}
    type_info = model.type_info
    model_table_name = model.table_name

    @opts[:select].map! do |sel|
        extract_select sel do |table, name, aliaz|
            if table
                if table == model_table_name
                    m = model
                else
                    a = model.many_to_one_associations[table] # || model.one_to_one_associations[table]
                    raise Engine2::E2Error.new("Association #{table} not found for model #{model}") unless a
                    m = Object.const_get(a[:class_name])
                end
                # raise Engine2::E2Error.new("Model not found for table #{table} in model #{model}") unless m
                info = m.type_info
            else
                info = type_info
            end

            f_info = info[name]
            raise Engine2::E2Error.new("Column #{name} not found for table #{table || model_table_name}") unless f_info

            table ||= model_table_name

            if table == model_table_name
                fields << name
            else
                fields << :"#{table}__#{name}"
                assoc = model.many_to_one_associations[table]
                unless assoc
                    # fail
                end
                joins[table] = assoc
            end

            if f_info[:dummy]
                nil
            # elsif f_info[:type] == :blob_store
            #     # (~{name => nil}).as :name
            #     # Sequel.char_length(name).as name
            #     nil
            else
                if table != model_table_name
                    if Sequel.alias_tables_in_joins
                        name.qualify(table).as(:"#{table}__#{name}")
                    else
                        name.qualify(table)
                    end
                else
                    name.qualify(table)
                end
            end
        end
    end

    @opts[:select].compact!

    joins.reduce(self) do |joined, (table, assoc)|
        assoc = model.many_to_one_associations[table] # || model.one_to_one_associations[table]
        m = Object.const_get(assoc[:class_name])
        keys = assoc[:qualified_key]
        keys = [keys] unless keys.is_a?(Array)
        joined.left_join(table, m.primary_keys.zip(keys))
    end
end

#with_proc(&blk) ⇒ Object 



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# File 'lib/engine2/core.rb', line 410

def with_proc &blk
    ds = clone
    ds.row_proc = blk
    ds
end