Make TRUNC and alias for TRUNCATE for compatibility with more databases.

Patch contributed by lukas.eder@gmail.com

h2/src/docsrc/help/help.csv

@@ -2785,7 +2785,7 @@ CALL HASH('SHA256', STRINGTOUTF8('Password'), 1000)
 "
 
 "Functions (Numeric)","TRUNCATE","
-TRUNCATE(numeric, digitsInt)
+{ TRUNC | TRUNCATE } (numeric, digitsInt)
 ","
 Truncates to a number of digits (to the next value closer to 0).
 This method returns a double.

h2/src/docsrc/html/changelog.html

@@ -22,6 +22,7 @@ Change Log
 </li><li>The table INFORMATION_SCHEMA.FUNCTION_ALIASES now includes a column TYPE_NAME.
 </li><li>Issue 378: when using views, the wrong values were bound to a parameter in some cases.
 </li><li>Terrence Huang has translated the error messages to Chinese. Thanks a lot!
+</li><li>TRUNC was added as an alias for TRUNCATE
 </li></ul>
 
 <h2>Version 1.3.166 (2012-04-08)</h2>

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

@@ -201,6 +201,8 @@ public class Function extends Expression implements FunctionCall {
         addFunction("TAN", TAN, 1, Value.DOUBLE);
         addFunction("TANH", TANH, 1, Value.DOUBLE);
         addFunction("TRUNCATE", TRUNCATE, 2, Value.DOUBLE);
+        // same as TRUNCATE
+        addFunction("TRUNC", TRUNCATE, 2, Value.DOUBLE);
         addFunction("HASH", HASH, 3, Value.BYTES);
         addFunction("ENCRYPT", ENCRYPT, 3, Value.BYTES);
         addFunction("DECRYPT", DECRYPT, 3, Value.BYTES);

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

@@ -9253,6 +9253,12 @@ select truncate(null, null) en, truncate(1.99, 0) e1, truncate(-10.9, 0) em10 fr
 > null 1.0 -10.0
 > rows: 1
 
+select trunc(null, null) en, trunc(1.99, 0) e1, trunc(-10.9, 0) em10 from test;
+> EN   E1  EM10
+> ---- --- -----
+> null 1.0 -10.0
+> rows: 1
+
 select ascii(null) en, ascii('') en, ascii('Abc') e65 from test;
 > EN   EN   E65
 > ---- ---- ---