[IMPALA-1594] cast empty string to decimal should be consistent with other numeric types

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Works for Me
• Affects Version/s: Impala 2.0
• Fix Version/s: Impala 2.3.0
• Labels: ramp-up sql-language
• Target Version: Product Backlog
• Assignee: Chris Channing
• Reporter: Matthew Jacobs
• Created: 10/Dec/14 19:58
• Updated: 04/Jan/17 23:58
• Resolved: 13/Oct/15 13:58

Description

From the user list:

[testnode01:21000] > select cast('' as DECIMAL(20,7));
Query: select cast('' as DECIMAL(20,7))
+---------------------------+
| cast('' as decimal(20,7)) |
+---------------------------+
| 0.0000000                 |
+---------------------------+
Fetched 1 row(s) in 0.04s




[testnode01:21000] > select cast('' as DOUBLE);
Query: select cast('' as DOUBLE)
+--------------------+
| cast('' as double) |
+--------------------+
| NULL               |
+--------------------+
Fetched 1 row(s) in 0.02s

Users that expect NULL can use the following workaround:

SELECT IF(field = '',null,CAST(field as DECIMAL(20,7)));

Issue Links

• duplicates: IMPALA-1952 Support CASTing a string literal representing a number in scientific notation to a DECIMAL.