Sybase 12.4.2 manual Converting data on insertion, 202

Converting data on insertion

213	NULL	190	152.00	1
24	NULL	215	172.00	2

(2 rows affected)

If you later load data from another file into ps_partkey and ps_availqty, insertions begin correctly at the next row, as shown below.

LOAD TABLE partsupp (ps_partkey ASCII(6), ps_availqty ASCII(6), FILLER(2))

FROM ’C:\\iq\\archive\\mill2.txt’

	SELECT *, rowid(partsupp) FROM partsupp
ps_partkey	ps_suppkey	ps_availqty	ps_value	rowid(partsupp)
----------	----------	-----------	--------	---------------
213	NULL	190	152.00	1
24	NULL	215	172.00	2
28	NULL	490	NULL	3
211	NULL	15	NULL	4

(4 rows affected)

Previewing partial- width inserts

To calculate and insert the values for ps_value, you need to repeat the INSERT statement shown earlier in this example, changing the START ROW ID value to the new row number, 3.

Given the possibility of errors if you do a partial-width insert incorrectly, it is a good idea to preview these inserts. The PREVIEW load option lets you see the layout of input in the destination table. This option is available in LOAD TABLE, but not in the INSERT command.

Converting data on insertion

The data you enter into your Adaptive Server IQ database will likely come from diverse sources. Not all of your data will match the Adaptive Server IQ data types exactly. Some of it will need to be converted. Data is converted in two ways: explicitly and implicitly. For example, to insert CHAR data into an INT column you must convert it explicitly.

Implicit conversions can occur:

•When you insert data selected from another column in the same database

202