private TResult ExecuteFirstFunc <TResult>(MethodCallExpression methodCall)
{
List <T> data = null;
if (methodCall.Arguments.Count == 2)
{
var lambda = (methodCall.Arguments[1] as UnaryExpression).Operand as LambdaExpression;
SelectExpressionResolver <T> selectResolver = new SelectExpressionResolver <T>();
WhereExpressionResolver <T> whereResolver = new WhereExpressionResolver <T>();
whereResolver.Resolve(lambda);
if (methodCall.Arguments[0] is MethodCallExpression)
{
ExpressionResolverManager <T> manager = new ExpressionResolverManager <T>(methodCall.Arguments[0] as MethodCallExpression).Resolve();
var sql = $"SELECT TOP 1 {selectResolver.SQL} FROM {typeof(T).TableName()} WHERE {$"{whereResolver.SQL} AND {manager.WhereResolver.SQL}"} {manager.GroupByResolver.SQL} {manager.OrderByResolver.SQL}";
var parameters = whereResolver.SqlParameters.Concat(manager.WhereResolver.SqlParameters);
data = DatabaseOperator.ExecuteReader <T>(DatabaseOperator.connection, sql, parameters.ToArray());
}
else if (methodCall.Arguments[0] is ConstantExpression)
{
var sql = $"SELECT TOP 1 {selectResolver.SQL} FROM {typeof(T).TableName()} WHERE {whereResolver.SQL}";
data = DatabaseOperator.ExecuteReader <T>(DatabaseOperator.connection, sql, whereResolver.SqlParameters);
}
}
else if (methodCall.Arguments.Count == 1)
{
var manager = new ExpressionResolverManager <T>(methodCall.Arguments[0] as MethodCallExpression).Resolve();
var sql = $"SELECT TOP 1 {manager.SelectResolver.SQL} FROM {typeof(T).TableName()} WHERE {manager.WhereResolver.SQL} {manager.GroupByResolver.SQL} {manager.OrderByResolver.SQL}";
data = DatabaseOperator.ExecuteReader <T>(DatabaseOperator.connection, sql, manager.WhereResolver.SqlParameters);
}
var ret = Convert.ChangeType((dynamic)data[0], typeof(T));
return((TResult)(object)ret);
}
private TResult ExecuteNoneFunc <TResult>()
{
SelectExpressionResolver <T> selectResolver = new SelectExpressionResolver <T>();
string sql = $"SELECT {selectResolver.SQL} FROM {typeof(T).TableName()}";
var data = DatabaseOperator.ExecuteReader <T>(DatabaseOperator.connection, sql);
return((TResult)(object)data);
}
