Warren,
Suggested code for using REPLACE INTO with an insert policy.
Adrian
Index: lib/query.h
===================================================================
--- lib/query.h (revision 2696)
+++ lib/query.h (working copy)
@@ -1140,6 +1140,94 @@
return *this;
}
+ /// \brief Replace multiple new rows using an insert policy to
+ /// control how the REPLACE statements are created using
+ /// items from an STL container.
+ ///
+ /// \param first iterator pointing to first element in range to
+ /// replace
+ /// \param last iterator pointing to one past the last element to
+ /// replace
+ /// \param policy insert policy object, see insertpolicy.h for
+ /// details
+ ///
+ /// \sa insert()
+ template <class Iter, class InsertPolicy>
+ Query& replacefrom(Iter first, Iter last, InsertPolicy& policy)
+ {
+ bool success = true;
+ bool empty = true;
+
+ reset();
+
+ if (first == last) {
+ return *this; // empty set!
+ }
+
+ typename InsertPolicy::access_controller ac(*conn_);
+
+ for (Iter it = first; it != last; ++it) {
+ if (policy.can_add(int(tellp()), *it)) {
+ if (empty) {
+ MYSQLPP_QUERY_THISPTR << std::setprecision(16) <<
+ "REPLACE INTO `" << it->table() << "` (" <<
+ it->field_list() << ") VALUES (";
+ }
+ else {
+ MYSQLPP_QUERY_THISPTR << ",(";
+ }
+
+ MYSQLPP_QUERY_THISPTR << it->value_list() << ')';
+
+ empty = false;
+ }
+ else {
+ // Execute what we've built up already, if there is anything
+ if (!empty) {
+ if (!exec()) {
+ success = false;
+ break;
+ }
+
+ empty = true;
+ }
+
+ // If we _still_ can't add, the policy is too strict
+ if (policy.can_add(int(tellp()), *it)) {
+ MYSQLPP_QUERY_THISPTR << std::setprecision(16) <<
+ "REPLACE INTO `" << it->table() << "` (" <<
+ it->field_list() << ") VALUES (" <<
+ it->value_list() << ')';
+
+ empty = false;
+ }
+ else {
+ // At this point all we can do is give up
+ if (throw_exceptions()) {
+ throw BadInsertPolicy("Insert policy is too strict");
+ }
+
+ success = false;
+ break;
+ }
+ }
+ }
+
+ // We might need to execute the last query here.
+ if (success && !empty && !exec()) {
+ success = false;
+ }
+
+ if (success) {
+ ac.commit();
+ }
+ else {
+ ac.rollback();
+ }
+
+ return *this;
+ }
+
/// \brief Insert new row unless there is an existing row that
/// matches on a unique index, in which case we replace it.
///
Attachment: [text/x-patch] query.h.patch
