• unknown's avatar
    Bug#23800: Outer fields in correlated subqueries is used in a temporary table · f8855142
    unknown authored
    created for sorting.
    
    Any outer reference in a subquery was represented by an Item_field object.
    If the outer select employs a temporary table all such fields should be
    replaced with fields from that temporary table in order to point to the 
    actual data. This replacement wasn't done and that resulted in a wrong
    subquery evaluation and a wrong result of the whole query.
    
    Now any outer field is represented by two objects - Item_field placed in the
    outer select and Item_outer_ref in the subquery. Item_field object is
    processed as a normal field and the reference to it is saved in the
    ref_pointer_array. Thus the Item_outer_ref is always references the correct
    field. The original field is substituted for a reference in the
    Item_field::fix_outer_field() function.
    
    New function called fix_inner_refs() is added to fix fields referenced from
    inner selects and to fix references (Item_ref objects) to these fields.
    
    The new Item_outer_ref class is a descendant of the Item_direct_ref class.
    It additionally stores a reference to the original field and designed to
    behave more like a field.
    
    
    sql/item.cc:
      Bug#23800: Correlated sub query returning incorrect results when operated upon.
      Now all outer fields are substituted with references to them (Item_outer_ref objects)
      in the Item_field::fix_outer_field() function.
      The original field is saved in the Item_outer_ref object.
    sql/item.h:
      Bug#23800: Correlated sub query returning incorrect results when operated upon.
      Added the Item_outer_ref class.
    sql/mysql_priv.h:
      Bug#23800: Correlated sub query returning incorrect results when operated upon.
      Added the fix_inner_refs() function prototype.
    sql/sql_delete.cc:
      Bug#23800: Correlated sub query returning incorrect results when operated upon.
      Added call to the fix_inner_refs() function.
    sql/sql_select.cc:
      Bug#23800: Correlated sub query returning incorrect results when operated upon.
      The new function called fix_inner_refs() is added.
    mysql-test/r/subselect.result:
      Added a test case for bug#23800: Correlated sub query returning incorrect results when
      operated upon.
    sql/sql_update.cc:
      Bug#23800: Correlated sub query returning incorrect results when operated upon.
      Added call to the fix_inner_refs() function.
    mysql-test/r/subselect3.result:
      Corrected test cases result after fix for bug#23800: Correlated sub query returning
      incorrect results when operated upon.
    mysql-test/t/subselect.test:
      Added a test case for bug#23800: Correlated sub query returning incorrect results when
      operated upon.
    sql/sql_lex.cc:
      Bug#23800: Correlated sub query returning incorrect results when operated upon.
      Added cleanup of the inner_refs_list.
    sql/sql_lex.h:
      Bug#23800: Correlated sub query returning incorrect results when operated upon.
      The inner_refs_list is added to the SELECT_LEX class.
    f8855142
sql_lex.cc 57.7 KB