I have a table containing latitude and longitude values stored as strings (VARCHAR
) which I'd like to convert to FLOAT (10,6)
.
However there doesn't appear to be a straightforward way to do this using CAST()
or CONVERT()
.
How can I convert these columns easily? This is a one-time conversion.
This question is related to
mysql
type-conversion
mysql> SELECT CAST(4 AS DECIMAL(4,3));
+-------------------------+
| CAST(4 AS DECIMAL(4,3)) |
+-------------------------+
| 4.000 |
+-------------------------+
1 row in set (0.00 sec)
mysql> SELECT CAST('4.5s' AS DECIMAL(4,3));
+------------------------------+
| CAST('4.5s' AS DECIMAL(4,3)) |
+------------------------------+
| 4.500 |
+------------------------------+
1 row in set (0.00 sec)
mysql> SELECT CAST('a4.5s' AS DECIMAL(4,3));
+-------------------------------+
| CAST('a4.5s' AS DECIMAL(4,3)) |
+-------------------------------+
| 0.000 |
+-------------------------------+
1 row in set, 1 warning (0.00 sec)
This will convert to a numeric value without the need to cast or specify length or digits:
STRING_COL+0.0
If your column is an INT
, can leave off the .0
to avoid decimals:
STRING_COL+0
Source: Stackoverflow.com