You enter the approximate numeric types—float, real, and double precision—as a mantissa followed by an optional exponent. The mantissa can include a positive or negative sign and a decimal point. The exponent, which begins after the character “e” or “E”, can include a sign but not a decimal point.
To evaluate approximate numeric data, Adaptive Server multiplies the mantissa by 10 raised to the given exponent. Table 7-1 shows examples of float, real, and double precision data:
Data entered |
Mantissa |
Exponent |
Value |
|---|---|---|---|
10E2 |
10 |
2 |
10 * 102 |
15.3e1 |
15.3 |
1 |
15.3 * 101 |
-2.e5 |
-2 |
5 |
-2 * 105 |
2.2e-1 |
2.2 |
-1 |
2.2 * 10-1 |
+56E+2 |
56 |
2 |
56 * 102 |
The column’s binary precision determines the maximum number of binary digits allowed in the mantissa. For float columns, you can specify a precision of up to 48 digits; for real and double precision columns, the precision is machine-dependent. If a value exceeds the column’s binary precision, Adaptive Server flags the entry as an error.
| Copyright © 2005. Sybase Inc. All rights reserved. |
|
|
