(PHP 5, PHP 7)
mysqli_stmt::attr_set -- mysqli_stmt_attr_set — Used to modify the behavior of a prepared statement
面向对象风格
$attr
, int $mode
)过程化风格
Used to modify the behavior of a prepared statement. This function may be called multiple times to set several attributes.
stmt仅以过程化样式：由 mysqli_stmt_init() 返回的 statement 标识。
attrThe attribute that you want to set. It can have one of the following values:
| Character | Description |
|---|---|
| MYSQLI_STMT_ATTR_UPDATE_MAX_LENGTH |
Setting to TRUE causes mysqli_stmt_store_result() to
update the metadata MYSQL_FIELD->max_length value.
|
| MYSQLI_STMT_ATTR_CURSOR_TYPE |
Type of cursor to open for statement when mysqli_stmt_execute()
is invoked. mode can be MYSQLI_CURSOR_TYPE_NO_CURSOR
(the default) or MYSQLI_CURSOR_TYPE_READ_ONLY.
|
| MYSQLI_STMT_ATTR_PREFETCH_ROWS |
Number of rows to fetch from server at a time when using a cursor.
mode can be in the range from 1 to the maximum
value of unsigned long. The default is 1.
|
If you use the MYSQLI_STMT_ATTR_CURSOR_TYPE option with MYSQLI_CURSOR_TYPE_READ_ONLY, a cursor is opened for the statement when you invoke mysqli_stmt_execute(). If there is already an open cursor from a previous mysqli_stmt_execute() call, it closes the cursor before opening a new one. mysqli_stmt_reset() also closes any open cursor before preparing the statement for re-execution. mysqli_stmt_free_result() closes any open cursor.
If you open a cursor for a prepared statement, mysqli_stmt_store_result() is unnecessary.
modeThe value to assign to the attribute.