public SqlQueryable <T> Count(Expression <Func <T, object> > expression = null)
{
this._sqlBuilder.SetSqlCommandType(SqlCommandType.Calculate);
this.Clear();
if (expression == null)
{
string tableName = typeof(T).GetTableName(_sqlBuilder._dbSqlParser);
this._sqlBuilder.SetTableAlias(tableName);
string tableAlias = this._sqlBuilder.GetTableAlias(tableName);
if (!string.IsNullOrWhiteSpace(tableAlias))
{
tableName += " " + tableAlias;
}
this._sqlBuilder.SqlCalculateStr = $"select Count(*) from {tableName}";
}
else
{
SqlProvider.Count(expression.Body, this._sqlBuilder);
}
return(this);
}
protected override SqlBuilder Count(ParameterExpression expression, SqlBuilder sqlBuilder)
{
SqlProvider.Count(expression, sqlBuilder);
return(sqlBuilder);
}
protected override SqlBuilder Count(UnaryExpression expression, SqlBuilder sqlBuilder)
{
SqlProvider.Count(expression.Operand, sqlBuilder);
return(sqlBuilder);
}