Function make_cond

plugin/feedback/feedback.cc:90–134

Generate the COND tree for the condition pushdown This function takes a list of strings and generates an Item tree corresponding to the following expression: field LIKE str1 OR field LIKE str2 OR field LIKE str3 OR ... where 'field' is the first field in the table - VARIABLE_NAME field - and str1, str2... are strings from the list. This condition is used to filter the selected ro

    SELECT * FROM INFORMATION_SCHEMA.GLOBAL_VARIABLES WHERE ...
*/
static COND* make_cond(THD *thd, TABLE_LIST *tables, LEX_STRING *filter)
{
  Item_cond_or *res= NULL;
  /* A reference to this context will be stored in Item_field */
  Name_resolution_context *nrc= new (thd->mem_root) Name_resolution_context;
  LEX_CSTRING &db= tables->db;
  LEX_CSTRING &table= tables->alias;
  LEX_CSTRING &field= tables->table->field[0]->field_name;
  CHARSET_INFO *cs= &my_charset_latin1;

  if (!filter->str || !nrc)
    return 0;

  nrc->resolve_in_table_list_only(tables);
  nrc->select_lex= tables->select_lex;

  res= new (thd->mem_root) Item_cond_or(thd);
  if (!res)
    return OOM;

  for (; filter->str; filter++)
  {
    Item_field  *fld= new (thd->mem_root) Item_field(thd, nrc, db, table,
                                                     field);
    Item_string *pattern= new (thd->mem_root) Item_string(thd, filter->str,
                                                          (uint) filter->length, cs);
    Item_string *escape= new (thd->mem_root) Item_string(thd, "\\", 1, cs);

    if (!fld || !pattern || !escape)
      return OOM;

    Item_func_like *like= new (thd->mem_root) Item_func_like(thd, fld, pattern,
                                                             escape, 0);

    if (!like)
      return OOM;

    res->add(like, thd->mem_root);
  }

  if (res->fix_fields(thd, (Item**)&res))
    return OOM;

  return res;
}

/**
  System variables that we want to see in the feedback report