/// <summary>
/// Returns SQL statement for the provided SelectClause
/// </summary>
/// <param name="selectClause"></param>
/// <returns></returns>
public SelectStatementModel GetModel(SelectStatement selectClause)
{
var select = selectClause.IsDistinct ? "SELECT DISTINCT " : "SELECT ";
var from = "";
var where = "";
var limit = "";
//this is a pseudo select
if (selectClause.FromClause == null)
{
var _list = BuildSelectList(selectClause, null).ToList();
return(new SelectStatementModel()
{
Sql = select + SelectSql(_list),
SelectList = _list
});
}
//generate alias list
var aliasList = StatementGenerator.GetAliasList(selectClause.FromClause, GetModel);
//process from clause
if (selectClause.FromClause != null)
{
from = FromSql(selectClause.FromClause, aliasList, _formatter);
}
if (selectClause.WhereClause != null)
{
where = WhereSql(selectClause.WhereClause, aliasList, _formatter);
}
var selectList = BuildSelectList(selectClause, aliasList).ToList();
select = select + SelectSql(selectList);
var groupby = "";
if (selectList.Any(a => a.IsGroupRequired == true))
{
groupby = GroupBySql(selectList.Where(s => s.IsGroupRequired == false));
}
//set limit on result set
if (selectClause.ResultLimit > 0)
{
limit = "limit " + selectClause.ResultLimit;
}
return(new SelectStatementModel()
{
Sql = select + " " + from + " " + where + " " + groupby + " " + limit,
AliasList = aliasList,
SelectList = selectList.ToList(),
IsAllSelect = selectList.Aggregate(true, (a, b) => b.IsAllSelect & a)
});
}
private static ExpressionSql HandleExpression <T>(WhereClause <T> statement, IConnectorFormatter formatter)
{
if (statement == null)
{
return(null);
}
var aliasList = StatementGenerator.GetAliasList(statement.FromClause);
var fromSql = StatementGenerator.FromSql(statement.FromClause, aliasList, formatter);
var whereSql = StatementGenerator.WhereSql(statement, aliasList, formatter);
return(new ExpressionSql
{
WhereSql = whereSql,
FromSql = fromSql
});
}
