// set references to tables on targetSchema and create/update any missing or out-of-date tables
// if update existing is true, updates existing tables, otherwise validates existing tables
// NOTE: must be called from within write transaction
std::vector<std::pair<std::string, Property>> ObjectStore::create_tables(Group *group, Schema &target_schema, bool update_existing) {
// properties to delete
std::vector<std::pair<std::string,Property>> to_delete;
// first pass to create missing tables
std::vector<ObjectSchema *> to_update;
for (auto& object_schema : target_schema) {
bool created = false;
ObjectStore::table_for_object_type_create_if_needed(group, object_schema.name, created);
// we will modify tables for any new objectSchema (table was created) or for all if update_existing is true
if (update_existing || created) {
to_update.push_back(&object_schema);
}
}
// second pass adds/removes columns for out of date tables
for (auto& target_object_schema : to_update) {
TableRef table = table_for_object_type(group, target_object_schema->name);
ObjectSchema current_schema(group, target_object_schema->name);
std::vector<Property> &target_props = target_object_schema->persisted_properties;
// handle columns changing from required to optional
for (auto& current_prop : current_schema.persisted_properties) {
auto target_prop = target_object_schema->property_for_name(current_prop.name);
if (!target_prop || !property_can_be_migrated_to_nullable(current_prop, *target_prop))
continue;
target_prop->table_column = current_prop.table_column;
current_prop.table_column = current_prop.table_column + 1;
table->insert_column(target_prop->table_column, DataType(target_prop->type), target_prop->name, target_prop->is_nullable);
copy_property_values(current_prop, *target_prop, *table);
table->remove_column(current_prop.table_column);
current_prop.table_column = target_prop->table_column;
}
bool inserted_placeholder_column = false;
// remove extra columns
size_t deleted = 0;
for (auto& current_prop : current_schema.persisted_properties) {
current_prop.table_column -= deleted;
auto target_prop = target_object_schema->property_for_name(current_prop.name);
// mark object name & property pairs for deletion
if (!target_prop) {
to_delete.push_back(std::make_pair(current_schema.name, current_prop));
}
else if ((property_has_changed(current_prop, *target_prop) &&
!property_can_be_migrated_to_nullable(current_prop, *target_prop))) {
if (deleted == current_schema.persisted_properties.size() - 1) {
// We're about to remove the last column from the table. Insert a placeholder column to preserve
// the number of rows in the table for the addition of new columns below.
table->add_column(type_Bool, "placeholder");
inserted_placeholder_column = true;
}
table->remove_column(current_prop.table_column);
++deleted;
current_prop.table_column = npos;
}
}
// add missing columns
for (auto& target_prop : target_props) {
auto current_prop = current_schema.property_for_name(target_prop.name);
// add any new properties (no old column or old column was removed due to not matching)
if (!current_prop || current_prop->table_column == npos) {
switch (target_prop.type) {
// for objects and arrays, we have to specify target table
case PropertyType::Object:
case PropertyType::Array: {
TableRef link_table = ObjectStore::table_for_object_type(group, target_prop.object_type);
REALM_ASSERT(link_table);
target_prop.table_column = table->add_column_link(DataType(target_prop.type), target_prop.name, *link_table);
break;
}
default:
target_prop.table_column = table->add_column(DataType(target_prop.type),
target_prop.name,
target_prop.is_nullable);
break;
}
}
else {
target_prop.table_column = current_prop->table_column;
}
}
if (inserted_placeholder_column) {
// We inserted a placeholder due to removing all columns from the table. Remove it, and update the indices
// of any columns that we inserted after it.
table->remove_column(0);
for (auto& target_prop : target_props) {
target_prop.table_column--;
}
}
// update table metadata
if (target_object_schema->primary_key.length()) {
// if there is a primary key set, check if it is the same as the old key
if (current_schema.primary_key != target_object_schema->primary_key) {
set_primary_key_for_object(group, target_object_schema->name, target_object_schema->primary_key);
}
}
else if (current_schema.primary_key.length()) {
// there is no primary key, so if there was one nil out
set_primary_key_for_object(group, target_object_schema->name, "");
}
}
return to_delete;
}
// set references to tables on targetSchema and create/update any missing or out-of-date tables
// if update existing is true, updates existing tables, otherwise validates existing tables
// NOTE: must be called from within write transaction
bool ObjectStore::create_tables(Group *group, ObjectStore::Schema &target_schema, bool update_existing) {
bool changed = false;
// first pass to create missing tables
vector<ObjectSchema *> to_update;
for (auto& object_schema : target_schema) {
bool created = false;
ObjectStore::table_for_object_type_create_if_needed(group, object_schema.name, created);
// we will modify tables for any new objectSchema (table was created) or for all if update_existing is true
if (update_existing || created) {
to_update.push_back(&object_schema);
changed = true;
}
}
// second pass adds/removes columns for out of date tables
for (auto& target_object_schema : to_update) {
TableRef table = table_for_object_type(group, target_object_schema->name);
ObjectSchema current_schema(group, target_object_schema->name);
vector<Property> &target_props = target_object_schema->properties;
// add missing columns
for (auto& target_prop : target_props) {
auto current_prop = current_schema.property_for_name(target_prop.name);
// add any new properties (new name or different type)
if (!current_prop || property_has_changed(*current_prop, target_prop)) {
switch (target_prop.type) {
// for objects and arrays, we have to specify target table
case PropertyTypeObject:
case PropertyTypeArray: {
TableRef link_table = ObjectStore::table_for_object_type(group, target_prop.object_type);
target_prop.table_column = table->add_column_link(DataType(target_prop.type), target_prop.name, *link_table);
break;
}
default:
target_prop.table_column = table->add_column(DataType(target_prop.type), target_prop.name);
break;
}
changed = true;
}
}
// remove extra columns
sort(begin(current_schema.properties), end(current_schema.properties), [](Property &i, Property &j) {
return j.table_column < i.table_column;
});
for (auto& current_prop : current_schema.properties) {
auto target_prop = target_object_schema->property_for_name(current_prop.name);
if (!target_prop || property_has_changed(current_prop, *target_prop)) {
table->remove_column(current_prop.table_column);
changed = true;
}
}
// update table metadata
if (target_object_schema->primary_key.length()) {
// if there is a primary key set, check if it is the same as the old key
if (current_schema.primary_key != target_object_schema->primary_key) {
set_primary_key_for_object(group, target_object_schema->name, target_object_schema->primary_key);
changed = true;
}
}
else if (current_schema.primary_key.length()) {
// there is no primary key, so if there was one nil out
set_primary_key_for_object(group, target_object_schema->name, "");
changed = true;
}
}
return changed;
}