/// <summary>An OrmConnection method that selects.</summary>
/// <typeparam name="T">Generic type parameter.</typeparam>
/// <param name="expression">The expression.</param>
/// <param name="flags"></param>
/// <returns>A List<T></returns>
public async Task <IEnumerable <T> > SelectAsync <T>(Action <TypedSelectStatement <T> > expression, CommandFlags flags = CommandFlags.Buffered)
{
TypedSelectStatement <T> select = new TypedSelectStatement <T>(DialectProvider);
expression(select);
return(await this.QueryAsync <T>(DialectProvider.ToSelectStatement(select.Statement, flags)));
}
/// <summary>An OrmConnection method that selects.</summary>
/// <typeparam name="T">Generic type parameter.</typeparam>
/// <param name="predicate">The predicate.</param>
/// <param name="flags"></param>
/// <returns>A List<T></returns>
public async Task <IEnumerable <T> > SelectAsync <T>(Expression <Func <T, bool> > predicate, CommandFlags flags = CommandFlags.Buffered)
{
TypedSelectStatement <T> select = new TypedSelectStatement <T>(DialectProvider);
select.Where(predicate);
return(await this.QueryAsync <T>(DialectProvider.ToSelectStatement(select.Statement, flags)));
}
/// <summary>
/// Execute a query that return a single value
/// </summary>
/// <example>
/// int maxAgeUnder50 = db.Scalar<Person, int>(x => Sql.Max(x.Age));
/// </example>
/// <param name="field">The expression that return the single value</param>
/// <typeparam name="T">The Type specifying the target table</typeparam>
/// <typeparam name="TKey">The Type of the result</typeparam>
/// <returns></returns>
public async Task <TKey> GetScalarAsync <T, TKey>(Expression <Func <T, TKey> > field)
{
var select = new TypedSelectStatement <T>(DialectProvider);
select.Select(field);
return(await this.ExecuteScalarAsync <TKey>(
DialectProvider.ToSelectStatement(select.Statement, CommandFlags.None)));
}
public async Task <long> CountAsync <T>(Action <TypedSelectStatement <T> > expression)
{
TypedSelectStatement <T> select = new TypedSelectStatement <T>(DialectProvider);
expression(select);
return(await this.ExecuteScalarAsync <long>(DialectProvider.ToCountStatement(select.Statement, CommandFlags.None)));
}
/// <summary>An OrmConnection method that gets a scalar.</summary>
/// <typeparam name="T"> Generic type parameter.</typeparam>
/// <typeparam name="TKey">Type of the key.</typeparam>
/// <param name="field"> The field.</param>
/// <returns>The scalar.</returns>
public async Task <TKey> GetScalarAsync <T, TKey>(Expression <Func <T, TKey> > field)
{
//int maxAgeUnder50 = db.Scalar<Person, int>(x => Sql.Max(x.Age));
TypedSelectStatement <T> select = new TypedSelectStatement <T>(DialectProvider);
select.Select(field);
return(await this.ExecuteScalarAsync <TKey>(DialectProvider.ToSelectStatement(select.Statement, CommandFlags.None)));
}
public void Can_select_count_with_where_Statement()
{
CreateModelWithFieldsOfDifferentTypes();
using (var conn = OpenDbConnection())
{
var v = new TypedSelectStatement <ModelWithFieldsOfDifferentTypes>(_connectionFactory.DialectProvider);
v.Where(x => x.Bool);
var select = _connectionFactory.DialectProvider.ToSelectStatement(v.Statement, CommandFlags.None);
Assert.AreEqual(5, conn.Count <ModelWithFieldsOfDifferentTypes>(x => { x.Where(q => q.Bool); }));
}
}
