original_string: public function dateSub( $column, $expr, $type )
      {
          $type = $this->intervalMap[$type];
          $column = $this->getIdentifier( $column );
  
          if ( $column != 'NOW()' )
          {
              $column = "CAST( {$column} AS TIMESTAMP )";
          }
  
          return " {$column} - INTERVAL '{$expr}' {$type} ";
      }
code: public function dateSub( $column, $expr, $type )
      {
          $type = $this->intervalMap[$type];
          $column = $this->getIdentifier( $column );
  
          if ( $column != 'NOW()' )
          {
              $column = "CAST( {$column} AS TIMESTAMP )";
          }
  
          return " {$column} - INTERVAL '{$expr}' {$type} ";
      }
code_tokens: public function dateSub ( $ column , $ expr , $ type ) { $ type = $ this -> intervalMap [ $ type ] ; $ column = $ this -> getIdentifier ( $ column ) ; if ( $ column != 'NOW()' ) { $ column = "CAST( {$column} AS TIMESTAMP )" ; } return " {$column} - INTERVAL '{$expr}' {$type} " ; }
docstring: Returns the SQL that subtracts an interval from a timestamp value.
  
  @param string $column
  @param numeric $expr
  @param string $type one of SECOND, MINUTE, HOUR, DAY, MONTH, or YEAR
  @return string
docstring_tokens: Returns the SQL that subtracts an interval from a timestamp value .