Better string representation for decimal values (for example 0.00000000 instead of 0E-26).

h2/src/docsrc/html/changelog.html

@@ -18,7 +18,8 @@ Change Log
 <h1>Change Log</h1>
 
 <h2>Next Version (unreleased)</h2>
-<ul><li>Prepared statements could only be re-used if the same data types were used
+<ul><li>Better string representation for decimal values (for example 0.00000000 instead of 0E-26).
+</li><li>Prepared statements could only be re-used if the same data types were used
     the second time they were executed.
 </li><li>In error messages about referential constraint violation, the values are now included.
 </li><li>SCRIPT and RUNSCRIPT: the password can now be set using a prepared statement.

h2/src/main/org/h2/value/ValueDecimal.java

@@ -134,7 +134,12 @@ public class ValueDecimal extends Value {
 
     public String getString() {
         if (valueString == null) {
-            valueString = value.toString();
+            String p = value.toPlainString();
+            if (p.length() < 40) {
+                valueString = p;
+            } else {
+                valueString = value.toString();
+            }
         }
         return valueString;
     }

h2/src/test/org/h2/test/testSimple.in.txt

+select 1.00 / 3 * 0.00;
+> 0.00000000000000000000000000000;
+select 1.00000 / 3 * 0.0000;
+> 0.0000000000000000000000000000000000;
+select 1.0000000 / 3 * 0.00000;
+> 0.0000000000000000000000000000000000000;
+select 1.0000000 / 3 * 0.000000;
+> 0E-38;
 select substr('[Hello]', 2, 5);
 > Hello;
 select substr('Hello World', -5);