Improved date / time arithmetics. Adding and subtracting a floating point value…

Improved date / time arithmetics. Adding and subtracting a floating point value from a date or timestamp is now supported.

h2/src/docsrc/html/changelog.html

@@ -18,7 +18,9 @@ Change Log
 <h1>Change Log</h1>
 
 <h2>Next Version (unreleased)</h2>
-<ul><li>When creating a BLOB with in InputStream or a CLOB with a Reader, and the InputStream or Reader
+<ul><li>Improved date / time arithmetics. Adding and subtracting a 
+    floating point value from a date or timestamp is now supported.
+</li><li>When creating a BLOB with in InputStream or a CLOB with a Reader, and the InputStream or Reader
     threw an non-IOException, then the LOB storage was broken when storing LOBs in the database.
 </li><li>EXPLAIN SELECT didn't include the sample size if one was set.
 </li><li>Improved EXPLAIN plan formatting and documentation.

h2/src/main/org/h2/expression/Operation.java

@@ -14,6 +14,7 @@ import org.h2.table.TableFilter;
 import org.h2.util.MathUtils;
 import org.h2.value.DataType;
 import org.h2.value.Value;
+import org.h2.value.ValueInt;
 import org.h2.value.ValueNull;
 import org.h2.value.ValueString;
 
@@ -210,6 +211,16 @@ public class Operation extends Expression {
                         f.setParameter(2, right);
                         f.doneWithParameters();
                         return f.optimize(session);
+                    } else if (l == Value.DECIMAL || l == Value.FLOAT || l == Value.DOUBLE) {
+                        // Oracle date add
+                        Function f = Function.getFunction(session.getDatabase(), "DATEADD");
+                        f.setParameter(0, ValueExpression.get(ValueString.get("SECOND")));
+                        left = new Operation(Operation.MULTIPLY, ValueExpression.get(ValueInt
+                                .get(60 * 60 * 24)), left);
+                        f.setParameter(1, left);
+                        f.setParameter(2, right);
+                        f.doneWithParameters();
+                        return f.optimize(session);
                     } else if (l == Value.TIME && r == Value.TIME) {
                         dataType = Value.TIME;
                         return this;
@@ -228,6 +239,18 @@ public class Operation extends Expression {
                         f.setParameter(2, left);
                         f.doneWithParameters();
                         return f.optimize(session);
+                    } else if ((l == Value.DATE || l == Value.TIMESTAMP) && (r == Value.DECIMAL || r == Value.FLOAT || r == Value.DOUBLE)) {
+                        // Oracle date subtract
+                        Function f = Function.getFunction(session.getDatabase(), "DATEADD");
+                        f.setParameter(0, ValueExpression.get(ValueString.get("SECOND")));
+                        right = new Operation(Operation.MULTIPLY, ValueExpression.get(ValueInt
+                                .get(60 * 60 * 24)), right);
+                        right = new Operation(NEGATE, right, null);
+                        right = right.optimize(session);
+                        f.setParameter(1, right);
+                        f.setParameter(2, left);
+                        f.doneWithParameters();
+                        return f.optimize(session);
                     } else if (l == Value.DATE || l == Value.TIMESTAMP) {
                         if (r == Value.TIME) {
                             dataType = Value.TIMESTAMP;

h2/src/test/org/h2/test/test-1.3.txt

@@ -53,6 +53,24 @@ select ts + t + t - t x from test;
 > 2010-01-01 01:00:00.0
 > rows: 1
 
+select ts + t * 0.5 x from test;
+> X
+> ---------------------
+> 2010-01-01 00:30:00.0
+> rows: 1
+
+select ts + 0.5 x from test;
+> X
+> ---------------------
+> 2010-01-01 12:00:00.0
+> rows: 1
+
+select ts - 1.5 x from test;
+> X
+> ---------------------
+> 2009-12-30 12:00:00.0
+> rows: 1
+
 select ts + 0.5 * t + t - t x from test;
 > X
 > ---------------------