斜槓人生

--theDate,theTime的DataType=int，column_size=4

SELECT 
    theDate,
    theTime,
    theDate :: VARCHAR(8) || Lpad(theTime :: VARCHAR(6), 6, '0') AS theDateTime 
FROM 
    TableA;

各種格式：

SELECT 
        current as DateTimeNow,
        to_char(current,'%Y%m%d') as yyyyMMdd,
        to_char(current,'%Y_%m_%d') as yyyy_MM_dd,
        to_char(current,'%Y%m%d %H%M%S') as yyyyMMddHHmmss,
        to_char(current,'%H%M%S') as HHmmss, 
        to_char(current,'%H:%M:%S') as HH_mm_ss
    FROM 
        systables 
    WHERE 
        tabid= 1;