public override string GenerateSelect <T>(out IList <QueryInfo> parameters, List <Expression <Func <T, bool> > > where = null, Dictionary <Expression <Func <T, object> >, RowOrder> orderBy = null, int page = 1, int count = int.MaxValue)
{
parameters = new List <QueryInfo>();
var builder = new StringBuilder();
var tableName = DotEntityDb.GetTableNameForType <T>();
var whereString = "";
if (where != null)
{
var parser = new ExpressionTreeParser();
var whereStringBuilder = new List <string>();
foreach (var wh in where)
{
whereStringBuilder.Add(parser.GetWhereString(wh));
}
parameters = parser.QueryInfoList;
whereString = string.Join(" AND ", whereStringBuilder).Trim();
}
var orderByStringBuilder = new List <string>();
var orderByString = "";
if (orderBy != null)
{
var parser = new ExpressionTreeParser();
foreach (var ob in orderBy)
{
orderByStringBuilder.Add(parser.GetOrderByString(ob.Key) + (ob.Value == RowOrder.Descending ? " DESC" : ""));
}
orderByString = string.Join(", ", orderByStringBuilder).Trim(',');
}
// make the query now
builder.Append($"SELECT {QueryParserUtilities.GetSelectColumnString(new List<Type>() { typeof(T) })} FROM ");
builder.Append(tableName.ToEnclosed());
if (!string.IsNullOrEmpty(whereString))
{
builder.Append(" WHERE " + whereString);
}
if (!string.IsNullOrEmpty(orderByString))
{
builder.Append(" ORDER BY " + orderByString);
}
if (page > 1 || count != int.MaxValue)
{
var offset = (page - 1) * count;
builder.Append($" LIMIT {offset},{count}");
}
var query = builder.ToString().Trim() + ";";
return(query);
}
