Add Column.writeColumns(StringBuilder, Column[], String, String)

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

@@ -26,7 +26,6 @@ import org.h2.result.Row;
 import org.h2.table.Column;
 import org.h2.table.Table;
 import org.h2.table.TableFilter;
-import org.h2.util.StatementBuilder;
 import org.h2.value.Value;
 
 /**
@@ -268,20 +267,11 @@ public class Merge extends CommandWithValues {
             }
             keys = idx.getColumns();
         }
-        StatementBuilder buff = new StatementBuilder("UPDATE ");
-        targetTable.getSQL(buff.builder()).append(" SET ");
-        for (Column c : columns) {
-            buff.appendExceptFirst(", ");
-            c.getSQL(buff.builder()).append("=?");
-        }
-        buff.append(" WHERE ");
-        buff.resetCount();
-        for (Column c : keys) {
-            buff.appendExceptFirst(" AND ");
-            c.getSQL(buff.builder()).append("=?");
-        }
-        String sql = buff.toString();
-        update = session.prepare(sql);
+        StringBuilder builder = new StringBuilder("UPDATE ");
+        targetTable.getSQL(builder).append(" SET ");
+        Column.writeColumns(builder, columns, ", ", "=?").append(" WHERE ");
+        Column.writeColumns(builder, keys, " AND ", "=?");
+        update = session.prepare(builder.toString());
     }
 
     @Override

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

@@ -24,7 +24,6 @@ import org.h2.result.ResultInterface;
 import org.h2.result.Row;
 import org.h2.table.Column;
 import org.h2.table.Table;
-import org.h2.util.StatementBuilder;
 import org.h2.value.Value;
 
 /**
@@ -266,20 +265,11 @@ public class Replace extends CommandWithValues {
                 return;
             }
         }
-        StatementBuilder buff = new StatementBuilder("UPDATE ");
-        table.getSQL(buff.builder()).append(" SET ");
-        for (Column c : columns) {
-            buff.appendExceptFirst(", ");
-            c.getSQL(buff.builder()).append("=?");
-        }
-        buff.append(" WHERE ");
-        buff.resetCount();
-        for (Column c : keys) {
-            buff.appendExceptFirst(" AND ");
-            c.getSQL(buff.builder()).append("=?");
-        }
-        String sql = buff.toString();
-        update = session.prepare(sql);
+        StringBuilder builder = new StringBuilder("UPDATE ");
+        table.getSQL(builder).append(" SET ");
+        Column.writeColumns(builder, columns, ", ", "=?").append(" WHERE ");
+        Column.writeColumns(builder, keys, " AND ", "=?");
+        update = session.prepare(builder.toString());
     }
 
     @Override

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

@@ -1484,18 +1484,13 @@ public class Select extends Query {
                 }
             }
         }
-        buff.resetCount();
         buff.append("SELECT");
         if (isAnyDistinct()) {
             buff.append(" DISTINCT");
             if (distinctExpressions != null) {
                 buff.append(" ON(");
-                for (Expression distinctExpression: distinctExpressions) {
-                    buff.appendExceptFirst(", ");
-                    distinctExpression.getSQL(buff.builder());
-                }
+                Expression.writeExpressions(buff.builder(), distinctExpressions);
                 buff.append(')');
-                buff.resetCount();
             }
         }
         for (int i = 0; i < visibleColumnCount; i++) {

h2/src/main/org/h2/table/Column.java

@@ -105,6 +105,30 @@ public class Column {
         return builder;
     }
 
+    /**
+     * Appends the specified columns to the specified builder.
+     *
+     * @param builder
+     *            string builder
+     * @param columns
+     *            columns
+     * @param separator
+     *            separator
+     * @param suffix
+     *            additional SQL to append after each column
+     * @return the specified string builder
+     */
+    public static StringBuilder writeColumns(StringBuilder builder, Column[] columns, String separator,
+            String suffix) {
+        for (int i = 0, l = columns.length; i < l; i++) {
+            if (i > 0) {
+                builder.append(separator);
+            }
+            columns[i].getSQL(builder).append(suffix);
+        }
+        return builder;
+    }
+
     public Column(String name, int valueType) {
         this(name, TypeInfo.getTypeInfo(valueType));
     }