internal static Task <T> SingleAsync <T>(this IDbCommand dbCmd, SqlExpression <T> expression, CancellationToken token)
{
string sql = expression.Limit(1).SelectInto <T>();
return(dbCmd.ExprConvertToAsync <T>(sql, expression.Params, token));
}
public IUntypedSqlExpression Limit(int skip, int rows)
{
q.Limit(skip, rows);
return(this);
}
/// <summary>
/// Returns true if the Query returns any records that match the supplied SqlExpression, E.g:
/// <para>db.ExistsAsync(db.From<Person>().Where(x => x.Age < 50))</para>
/// </summary>
public static Task <bool> ExistsAsync <T>(this IDbConnection dbConn, SqlExpression <T> expression, CancellationToken token = default)
{
return(dbConn.Exec(dbCmd => dbCmd.ScalarAsync(expression.Limit(1).Select("'exists'"), token).Then(x => x != null)));
}
/// <summary>
/// Returns true if the Query returns any records that match the supplied SqlExpression, E.g:
/// <para>db.Exists(db.From<Person>().Where(x => x.Age < 50))</para>
/// </summary>
public static bool Exists <T>(this IDbConnection dbConn, SqlExpression <T> expression)
{
return(dbConn.Exec(dbCmd => dbCmd.Scalar(expression.Limit(1).Select("'exists'"))) != null);
}
internal static T Single <T>(this IDbCommand dbCmd, SqlExpression <T> q)
{
string sql = q.Limit(1).SelectInto <T>();
return(dbCmd.ExprConvertTo <T>(sql, q.Params, onlyFields: q.OnlyFields));
}
internal static T Single <T>(this IDbCommand dbCmd, SqlExpression <T> expression)
{
string sql = expression.Limit(1).ToSelectStatement();
return(dbCmd.ExprConvertTo <T>(sql));
}
internal static T Single <T>(this IDbCommand dbCmd, SqlExpression <T> expression)
{
string sql = expression.Limit(1).SelectInto <T>();
return(dbCmd.ExprConvertTo <T>(sql, expression.Params));
}
internal static T Single <T>(this IDbCommand dbCmd, SqlExpression <T> expression, List <string> fieldNames = null)
{
string sql = expression.Limit(1).SelectInto <T>(fieldNames);
return(dbCmd.ExprConvertTo <T>(sql));
}