/// <summary>
/// 生成统计数据行数的SQL
/// </summary>
/// <param name="CountSql"></param>
/// <param name="Col"></param>
/// <returns></returns>
protected virtual ODAScript GetCountSql(IODAColumns Col)
{
if (_Groupby.Count > 0 || _Having.Count > 0)
{
throw new ODAException(10006, "Do not count the [Group by] cmd,You should probably use [ ToView(Columns).Count()] instead.");
}
ODAScript sql = new ODAScript()
{
ScriptType = SQLType.Select,
DataBaseId = this.DataBaseId,
};
if (_Distinct)
{
sql.SqlScript.Append("SELECT COUNT(DISTINCT ");
}
else
{
sql.SqlScript.Append("SELECT COUNT(");
}
if (System.Object.ReferenceEquals(Col, null))
{
sql.SqlScript.Append("*");
}
else
{
string SubSelectSql = "";
ODAParameter[] SubSelectPrms = GetSelectColumns(",", out SubSelectSql, Col);
sql.SqlScript.Append(SubSelectSql);
if (SubSelectPrms != null && SubSelectPrms.Length > 0)
{
sql.ParamList.AddRange(SubSelectPrms);
}
}
sql.SqlScript.Append(") AS TOTAL_RECORD");
var fSql = GetFromSubString();
sql.Merge(fSql);
if (_WhereList.Count > 0 || _OrList.Count > 0)
{
sql.SqlScript.Append(" WHERE ");
var asql = GetWhereSubSql(_WhereList, " AND ");
sql.Merge(asql);
if (_OrList.Count > 0)
{
if (_WhereList.Count > 0)
{
sql.SqlScript.Append(" OR ");
}
var osql = GetWhereSubSql(_OrList, " OR ");
sql.Merge(osql);
}
}
return(sql);
}
/// <summary>
/// 在数据库中执行select count 语句,返统计结果
/// </summary>
/// <param name="Col"></param>
/// <returns></returns>
protected virtual int CountRecords(IODAColumns Col = null)
{
var sql = this.GetCountSql(Col);
var db = this.GetDBAccess(sql);
if (db == null)
throw new ODAException(10007, "ODACmd Count 没有执行程序");
object[] vl = db.SelectFirst(sql.SqlScript.ToString(), sql.ParamList.ToArray());
return int.Parse(vl[0].ToString());
}
/// <summary>
/// 在数据库中执行select count 语句,返统计结果
/// </summary>
/// <param name="Col"></param>
/// <returns></returns>
public virtual int Count(IODAColumns Col = null)
{
try
{
return(CountRecords(Col));
}
finally
{
this.Clear();
}
}
