OrmLite Utils

The Sql.In() API supports nesting and combining of multiple Typed SQL Expressions together in a single SQL Query, e.g:

var usaCustomerIds = db.From<Customer>(c => c.Country == "USA").Select(c => c.Id);
var usaCustomerOrders = db.Select(db.From<Order>()
    .Where(x => Sql.In(x.CustomerId, usaCustomerIds)));

By using Sql.In from within a SqlExpression<T>, multiple values can be checked for a match in your query.

db.Select<Author>(x => Sql.In(x.City, "London", "Madrid", "Berlin"));

var cities = new[] { "London", "Madrid", "Berlin" };
db.Select<Author>(x => Sql.In(x.City, cities));

Parametrized IN Values

OrmLite also supports providing collection of values which is automatically split into multiple DB parameters to simplify executing parameterized SQL with multiple IN Values, e.g:

var ids = new[]{ 1, 2, 3};
var results = db.Select<Table>("Id in (@ids)", new { ids });

var names = new List<string>{ "foo", "bar", "qux" };
var results = db.SqlList<Table>("SELECT * FROM Table WHERE Name IN (@names)", new { names });

Spread Util

The SqlSpread() API is useful to generate an escaped list of parameterized values for use in SQL IN() statements and SQL functions:

var dialect = db.Dialect();
dialect.SqlSpread(1, 2, 3);         //= 1,2,3
dialect.SqlSpread("A", "B", "C");   //= 'A','B','C'
dialect.SqlSpread("A'B", "C\"D");   //= 'A''B','C\"D'

Lazy Queries

APIs ending with Lazy yield an IEnumerable sequence letting you stream the results without having to map the entire resultset into a disconnected List of POCO's first, e.g:

var lazyQuery = db.SelectLazy<Person>("Age > @age", new { age = 40 });
// Iterate over a lazy sequence 
foreach (var person in lazyQuery) {

Save Methods

Save and SaveAll will Insert if no record with Id exists, otherwise it Updates.

Save will populate any [AutoIncrement] or [AutoId] Primary Keys, e.g:

item.Id // RDBMS populated Auto Id 

Alternatively you can also manually Select and Retrieve the Inserted RDBMS Auto Id in a single query with Insert APIs by specifying selectIdentity:true:

item.Id = db.Insert(item, selectIdentity:true);

Other examples

var topVIPs = db.WhereLazy<Person>(new { Age = 27 }).Where(p => IsVip(p)).Take(5)

Other Notes

  • All Insert, Update, and Delete methods take multiple params, while InsertAll, UpdateAll and DeleteAll take IEnumerables.
  • Methods containing the word Each return an IEnumerable<T> and are lazily loaded (i.e. non-buffered).