ASM 10g & 11g Upgrade downgrade test

2. 1.
4. I used to think that Integer=number (38,0)--38 is the maximum precision of number
8. Integer is a very large data type and can be represented as power (10,126)-1
12. Because the maximum of one byte represents 256, the largest of n bytes represents power (256,n) >=power (10,126)
16. n=53, an integer type uses a minimum of 53 bytes.
20. So the integer type is still as small as possible, generally rarely use such a large number. In particular, some people deal with the Boolean type;
24. Because Oracle does not have a Boolean type in its table structure, many people simply replace the Boolean type with an integer, which feels a bit "extravagant". Generally, char (1) is used to denote a Boolean type;' 0 ' means false, ' 1 ' indicates true
28. 2.
30. VB in the ToString method home DBNull converted into an empty string.
32. Can not speak DBNull converted to string method, Custom function:
34. public static string Getdbstring (Object obj) {
36. if (! ( obj is DBNull)) {
38. return (string) obj;
40. }
42. else {
44. return string. Empty;
46. }
48. }

ASM 10g & 11g Upgrade downgrade test