Question

I’m trying to construct a simple delete statement in mysql and can’t seem to get it right. I want to be able to delete a row using just the x and y fields without specifying the description field.

The table looks like this:

+------------------+-------------------+-------------+
| x                | y                 | description |
+------------------+-------------------+-------------+
|  52.847202686351 | -113.833362226293 |             |
| 52.6810078148914 |  -113.65208781223 |             |
| 52.7625225559979 | -113.937732343481 |             |
| 52.8985943615787 | -113.415881757543 |             |
| 53.0969562533962 | -113.479053144262 | millet      |
+------------------+-------------------+-------------+

Answer 1

Your problem is probably caused by imprecision of the float data type. Floats are notoriously difficult to use with exact comparisons. You might be better off storing this data as decimal type?

ALTER TABLE table MODIFY x DECIMAL(15,12);
ALTER TABLE table MODIFY y DECIMAL(15,12);