private long getIndexForProperty(Table table, string name)
{
for (int i = 0; i < table.ColumnCount; i++)
{
if (table.getColumnName(i).Equals(name))
{
return(i);
}
}
return(-1);
}
public override long execute(Realm realm, long version)
{
/*
* // Version 0
* class Person
* @Required
* String firstName;
* @Required
* String lastName;
* int age;
*
* // Version 1
* class Person
* @Required
* String fullName; // combine firstName and lastName into single field.
* int age;
*/
// Migrate from version 0 to version 1
if (version == 0)
{
Table personTable = realm.getTable(typeof(Person));
long fistNameIndex = getIndexForProperty(personTable, "firstName");
long lastNameIndex = getIndexForProperty(personTable, "lastName");
long fullNameIndex = personTable.addColumn(ColumnType.STRING, "fullName");
for (int i = 0; i < personTable.size(); i++)
{
personTable.setString(fullNameIndex, i, personTable.getString(fistNameIndex, i) + " " + personTable.getString(lastNameIndex, i));
}
personTable.removeColumn(getIndexForProperty(personTable, "firstName"));
personTable.removeColumn(getIndexForProperty(personTable, "lastName"));
version++;
}
/*
* // Version 2
* class Pet // add a new model class
* @Required
* String name;
* @Required
* String type;
*
* class Person
* @Required
* String fullName;
* int age;
* RealmList<Pet> pets; // add an array property
*
*/
// Migrate from version 1 to version 2
if (version == 1)
{
Table personTable = realm.getTable(typeof(Person));
Table petTable = realm.getTable(typeof(Pet));
long nameColumnIndex = petTable.addColumn(ColumnType.STRING, "name");
long typeColumnIndex = petTable.addColumn(ColumnType.STRING, "type");
long petsIndex = personTable.addColumnLink(ColumnType.LINK_LIST, "pets", petTable);
long fullNameIndex = getIndexForProperty(personTable, "fullName");
for (int i = 0; i < personTable.size(); i++)
{
if (personTable.getString(fullNameIndex, i).Equals("JP McDonald"))
{
long rowIndex = petTable.addEmptyRow();
petTable.setString(nameColumnIndex, rowIndex, "Jimbo");
petTable.setString(typeColumnIndex, rowIndex, "dog");
personTable.getUncheckedRow(i).getLinkList(petsIndex).add(rowIndex);
}
}
version++;
}
/*
* // Version 3
* class Pet
* @Required
* String name;
* int type; // type becomes int
*
* class Person
* String fullName; // fullName is nullable now
* RealmList<Pet> pets; // age and pets re-ordered
* int age;
*/
// Migrate from version 2 to version 3
if (version == 2)
{
Table personTable = realm.getTable(typeof(Person));
long fullNameIndex = getIndexForProperty(personTable, "fullName");
// fullName is nullable now.
personTable.convertColumnToNullable(fullNameIndex);
Table petTable = realm.getTable(typeof(Pet));
long oldTypeIndex = getIndexForProperty(petTable, "type");
long typeIndex = petTable.addColumn(ColumnType.INTEGER, "type");
for (int i = 0; i < petTable.size(); i++)
{
string type = petTable.getString(oldTypeIndex, i);
if (type.Equals("dog"))
{
petTable.setLong(typeIndex, i, 1);
}
else if (type.Equals("cat"))
{
petTable.setLong(typeIndex, i, 2);
}
else if (type.Equals("hamster"))
{
petTable.setLong(typeIndex, i, 3);
}
}
petTable.removeColumn(oldTypeIndex);
version++;
}
return(version);
}
private long getIndexForProperty(Table table, string name)
{
for (int i = 0; i < table.ColumnCount; i++)
{
if (table.getColumnName(i).Equals(name))
{
return i;
}
}
return -1;
}
