Using default values in INSERT INTO..SELECT..

Question

Hi,
I like to do following insert in Oracle 10g
INSERT
INTO tab1
x1,
x2
SELECT
NVL(y1,DEFAULT),
y2
FROM tab2
but oracle throws missing expression error. I don't want to substitute default values as it involves code change for any default value change. I suppose Oracle changes context to tab2 while SELECT, but is there any way to accomplishing the above INSERT?
Edited by: ponn_raj on Jan 14, 2009 4:52 AM

Answer 1

Hi,
Welcome to the forum!
DECLARE
  var number;
BEGIN
    INSERT INTO test
        (col1,
         col2)
    VALUES
        (1,
         NVL(var, 0));
    COMMIT;
END;
/Also you can create the table and assign default values to the columns that you want. See [CREATE TABLE|http://download.oracle.com/docs/cd/B19306_01/server.102/b14200/statements_7002.htm#i2095331].
From the link above:
DEFAULT
The DEFAULT clause lets you specify a value to be assigned to the column if a subsequent INSERT statement omits a value for the column. The datatype of the expression must match the datatype of the column. The column must also be long enough to hold this expression.
The DEFAULT expression can include any SQL function as long as the function does not return a literal argument, a column reference, or a nested function invocation.
Regards,
Edited by: Walter Fernández on Jan 14, 2009 10:44 AM