Skip to main content

bitmap_from_string

Description​

Converts a string into a BITMAP. The string is composed of a set of UINT64 numbers separated by commas. For example, the "0, 1, 2" string will be converted into a Bitmap, in which bits 0, 1 and 2 are set. If the input field is invalid, NULL will be returned.

This function deduplicates the input string during the conversion. It must be used with other functions, such as bitmap_to_string to return results on terminals.

Syntax​

BITMAP BITMAP_FROM_STRING(VARCHAR input)

Return value​

Returns a BITMAP value. If the input string is invalid, NULL is returned. If the input string is empty, an empty value is returned.

Examples​

-- The input is empty and an empty value is returned.
MySQL > select bitmap_to_string(bitmap_empty());
+----------------------------------+
| bitmap_to_string(bitmap_empty()) |
+----------------------------------+
|                                  |
+----------------------------------+

-- `0,1,2` is returned.
MySQL > select bitmap_to_string(bitmap_from_string("0, 1, 2"));
+-------------------------------------------------+
| bitmap_to_string(bitmap_from_string('0, 1, 2')) |
+-------------------------------------------------+
| 0,1,2                                           |
+-------------------------------------------------+

-- `-1` is an invalid input and NULL is returned.

MySQL > select bitmap_to_string(bitmap_from_string("-1, 0, 1, 2"));
+-----------------------------------+
| bitmap_from_string('-1, 0, 1, 2') |
+-----------------------------------+
| NULL                              |
+-----------------------------------+

-- 2^64 is an invalid input and NULL is returned.
MySQL > select bitmap_to_string(bitmap_from_string("0, 18446744073709551616"));
+-----------------------------------------------------------------+
| bitmap_to_string(bitmap_from_string('0, 18446744073709551616')) |
+-----------------------------------------------------------------+
| NULL                                                            |
+-----------------------------------------------------------------+

-- The input string is deduplicated.

MySQL > select bitmap_to_string(bitmap_from_string("0, 1, 1"));
+-------------------------------------------------+
| bitmap_to_string(bitmap_from_string('0, 1, 1')) |
+-------------------------------------------------+
| 0,1                                             |
+-------------------------------------------------+

keywords​

BITMAP_FROM_STRING,BITMAP