Use StringBuilder in MergeUsing and remove space before comma

h2/src/main/org/h2/command/dml/MergeUsing.java

@@ -25,7 +25,6 @@ import org.h2.result.Row;
 import org.h2.result.RowImpl;
 import org.h2.table.Table;
 import org.h2.table.TableFilter;
-import org.h2.util.StatementBuilder;
 import org.h2.util.Utils;
 import org.h2.value.Value;
 
@@ -343,10 +342,10 @@ public class MergeUsing extends Prepared {
 
     @Override
     public String getPlanSQL() {
-        StatementBuilder buff = new StatementBuilder("MERGE INTO ");
-        buff.append(targetTable.getSQL()).append('\n').append("USING ").append(query.getPlanSQL());
+        StringBuilder builder = new StringBuilder("MERGE INTO ");
+        builder.append(targetTable.getSQL()).append('\n').append("USING ").append(query.getPlanSQL());
         // TODO add aliases and WHEN clauses to make plan SQL more like original SQL
-        return buff.toString();
+        return builder.toString();
     }
 
     @Override

h2/src/main/org/h2/constraint/ConstraintReferential.java

@@ -567,7 +567,7 @@ public class ConstraintReferential extends Constraint {
         buff.append("UPDATE ").append(table.getSQL()).append(" SET ");
         buff.resetCount();
         for (IndexColumn c : columns) {
-            buff.appendExceptFirst(" , ");
+            buff.appendExceptFirst(", ");
             Parser.quoteIdentifier(buff.builder(), c.column.getName()).append("=?");
         }
     }