The select function generates a SQL SELECT query, which is used to read records from the database. select automatically checks whether the records might be "hidden", "deleted", or if they have a "start and end date". If pidInList is used (meaning a list of pages is rendered), the function also checks if the current user is allowed to see all records.

With the help of the select function, it is possible to show the content of a page on all pages. For example:

temp.leftContent = CONTENT
temp.leftContent {

    table = tt_content
    select {

        # The page with ID = 123 is the source.
        pidInList = 123

        # Sorting is the same as in the backend.
        orderBy = sorting

        # Only select the content of the left column.
        where = {#colPos}=1

        # Define the field with the language ID in tt_content.
        languageField = sys_language_uid

# Replace the mark ###LEFT### with the output of temp.leftContent.
marks.LEFT < temp.leftContent