[jOOQ#1334] Fix inaccurate simulation of TRUNC(number, decimals) for …

…Derby
digulla · May 11, 2012 · c1ae591 · c1ae591
1 parent e53a757
commit c1ae591
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Showing 3 changed files with 56 additions and 4 deletions.
diff --git a/jOOQ-test/src/org/jooq/test/_/testcases/FunctionTests.java b/jOOQ-test/src/org/jooq/test/_/testcases/FunctionTests.java
@@ -603,6 +603,15 @@ public void testFunctionsOnNumbers() throws Exception {
         Field<Double> f3d = floor(-2.0);
         Field<Double> f4d = ceil(-2.0);
 
+        Field<Float> f1e = round(0.0f);
+        Field<Float> f2e = round(0.0f, 2);
+        Field<Float> f3e = floor(0.0f);
+        Field<Float> f4e = ceil(0.0f);
+        Field<Float> f1f = round(0.0f);
+        Field<Float> f2f = round(0.0f, 2);
+        Field<Float> f3f = floor(0.0f);
+        Field<Float> f4f = ceil(0.0f);
+
         // Some arbitrary checks on having multiple select clauses
         Record record =
         create().select(f1a)
@@ -611,7 +620,10 @@ public void testFunctionsOnNumbers() throws Exception {
                 .select(f5a, f6a, f7a)
                 .select(f1b, f2b, f3b, f4b, f6b, f6b, f7b)
                 .select(f1c, f2c, f3c, f4c)
-                .select(f1d, f2d, f3d, f4d).fetchOne();
+                .select(f1d, f2d, f3d, f4d)
+                .select(f1e, f2e, f3e, f4e)
+                .select(f1f, f2f, f3f, f4f)
+                .fetchOne();
 
         assertNotNull(record);
         assertEquals("1.0", record.getValueAsString(f1a));
@@ -640,6 +652,16 @@ public void testFunctionsOnNumbers() throws Exception {
         assertEquals("-2.0", record.getValueAsString(f3d));
         assertEquals("-2.0", record.getValueAsString(f4d));
 
+        assertEquals("0.0", record.getValueAsString(f1e));
+        assertEquals("0.0", record.getValueAsString(f2e));
+        assertEquals("0.0", record.getValueAsString(f3e));
+        assertEquals("0.0", record.getValueAsString(f4e));
+
+        assertEquals("0.0", record.getValueAsString(f1f));
+        assertEquals("0.0", record.getValueAsString(f2f));
+        assertEquals("0.0", record.getValueAsString(f3f));
+        assertEquals("0.0", record.getValueAsString(f4f));
+
         // Greatest and least
         record = create().select(
             greatest(1, 2, 3, 4),

diff --git a/jOOQ/src/main/java/org/jooq/impl/Trunc.java b/jOOQ/src/main/java/org/jooq/impl/Trunc.java
@@ -35,12 +35,15 @@
  */
 package org.jooq.impl;
 
+import static java.math.BigDecimal.TEN;
 import static org.jooq.impl.Factory.field;
 import static org.jooq.impl.Factory.inline;
 import static org.jooq.impl.Factory.one;
 import static org.jooq.impl.Factory.zero;
+import static org.jooq.impl.Util.extractVal;
 
 import java.math.BigDecimal;
+import java.math.MathContext;
 
 import org.jooq.Configuration;
 import org.jooq.Field;
@@ -82,10 +85,18 @@ private final Field<T> getDateTimeFunction(Configuration configuration) {
     private final Field<T> getNumericFunction(Configuration configuration) {
         switch (configuration.getDialect()) {
             case ASE:
-
-            // This calculation is inaccurate for Derby
             case DERBY: {
-                Field<BigDecimal> power = Factory.power(inline(new BigDecimal("10.0")), decimals);
+                Field<BigDecimal> power;
+
+                // [#1334] if possible, calculate the power in Java to prevent
+                // inaccurate arithmetics in the Derby database
+                Integer decimalsVal = extractVal(decimals);
+                if (decimalsVal != null) {
+                    power = inline(TEN.pow(decimalsVal, MathContext.DECIMAL128));
+                }
+                else {
+                    power = Factory.power(inline(TEN), decimals);
+                }
 
                 return Factory.decode()
                     .when(field.sign().greaterOrEqual(zero()),

diff --git a/jOOQ/src/main/java/org/jooq/impl/Util.java b/jOOQ/src/main/java/org/jooq/impl/Util.java
@@ -1028,4 +1028,23 @@ static final Field<String> escapeForLike(Field<?> field) {
             return field.cast(String.class);
         }
     }
+
+    /**
+     * Utility method to check whether a field is a {@link Param}
+     */
+    static final boolean isVal(Field<?> field) {
+        return field instanceof Param;
+    }
+
+    /**
+     * Utility method to extract a value from a field
+     */
+    static final <T> T extractVal(Field<T> field) {
+        if (isVal(field)) {
+            return ((Param<T>) field).getValue();
+        }
+        else {
+            return null;
+        }
+    }
 }