dba_exists
(PHP 4, PHP 5, PHP 7, PHP 8)
dba_exists — Check whether key exists
說明
   dba_exists(string|array 
  $key, resource $dba): bool
   dba_exists() checks whether the specified
   key exists in the database.
  
參數
- 
key
- 
      The key the check is performed for. 
- 
dba
- 
      The database handler, returned by dba_open() or dba_popen(). 
返回值
   Returns true if the key exists, false otherwise.
  
參見
- dba_delete() - Delete DBA entry specified by key
- dba_fetch() - Fetch data specified by key
- dba_insert() - Insert entry
- dba_replace() - Replace or insert entry