OPENJPA-2775 improve JavaDoc for sub-second fractions
diff --git a/openjpa-jdbc/src/main/java/org/apache/openjpa/jdbc/sql/DBDictionary.java b/openjpa-jdbc/src/main/java/org/apache/openjpa/jdbc/sql/DBDictionary.java
index 0767fd6..ff72cd5 100644
--- a/openjpa-jdbc/src/main/java/org/apache/openjpa/jdbc/sql/DBDictionary.java
+++ b/openjpa-jdbc/src/main/java/org/apache/openjpa/jdbc/sql/DBDictionary.java
@@ -438,7 +438,9 @@
protected final Set<String> fixedSizeTypeNameSet = new HashSet<>();
/**
- * set of types that only accept a single precision...
+ * set of types that might have an optional fraction (sub-second) part.
+ * @{code @Column(scale=-1)} sets the fraction to zero.
+ * @{code @Column(scale=0)} will use the default behaviour (no fraction information generated)
*/
public final Set<String> fractionalTypeNameSet = new HashSet<>();
@@ -446,8 +448,8 @@
* Default amount of digits for fractional Types.
* This is not supported/required by every database.
*
- * This value is only being used if no explicit {@code @Column(scale=n)} is set.
- * Use {@code @Column(scale=-1)} to disable the scale
+ * This value is only being used if no explicit {@code @Column(scale=n)} is set or n is zero.
+ * Use {@code @Column(scale=-1)} to disable the explicit fraction part in the SQL generator.
* @see #fractionalTypeNameSet
* @see #getFractionLength(Column, String)
*/
@@ -2023,7 +2025,7 @@
}
/**
- * Only get's used if no explicit scale is used.
+ * Only get's used if no explicit scale is used (@{code @Column(scale=0)} which is the default).
* Attention! @{code @Column(scale=-1)} disables the scale of a column
* @return the fraction length of types which have a fraction
* @see #fractionalTypeNameSet
