DB2 SQL将CHAR转换为SMALLINT

Question

I have a CHAR column that I need to convert to a SMALLINT column. The CHAR column is defined as CHAR(4) and contains data like this '360 ' with a space at the end.

I tried to use the CAST function like this:

CAST(DCA_REVN_CD AS SMALLINT) AS REVN_CD

This is the error I get:

-420 THE VALUE OF A STRING ARGUMENT WAS NOT ACCEPTABLE TO THE SMALLINT FUNCTION.

Can anyone help? I realize it's probably because there is a space in the data.

Answer 1

As asked above...would TRIM() work?

Not sure if this would work, as I haven't coded in DB2 for a few years, but this did work with MSSQL:

CAST(RTRIM(LTRIM(DCA_REVN_CD)) AS SMALLINT) AS REVN_CD

or the DB2 version (I think):

CAST(TRIM(DCA_REVN_CD) AS SMALLINT) AS REVN_CD

Answer 2

If you only have trailing spaces, then the SMALLINT function or your CAST will work:

$ db2 "create table test (id smallint, value char(10))" ;
$ db2 "insert into test values (1, '1  ')" ;
$ db2 "insert into test values (2, '2 ')" ;
$ db2 "insert into test values (3, '3')" ;
$ db2 "select smallint(VALUE) from test";
1
-----------
          1
          2
          3

So, your CAST should work, which implies that you've got strings other than spaces in that column:

$db2 "insert into test values (4, '4 A')" ;
$db2 select SMALLINT(VALUE) from test";
SQL0420N  Invalid character found in a character string argument of the
function "SMALLINT".  SQLSTATE=22018

Sugguestion: If you're on db2 11 or later, you could use REGEXP_SUBSTR to extract just the digits from this column.