2017-07-18 111 views
0

给定一个包含表“TAB1”的数据库“firstdb”。此表是不是学生信息罢了,可表现为跟随从SQL数据库获得统计信息HTML

ID Last Name First Name Date of Birth  School    Specialty Sex 
01 yves   marco  03/03/2000  la roccade school  letter  man 
02 marchal  zeko   05-12-1999  johara school   letter  man 
03 ghisil  maria  15-03-2000  johara school   science women 
04 belbali  john   30-10-1999  lever school   science man 
05 santa   sofi   04-05-2000  la roccade school  science women 
06 yves   don   16/04/2000  la roccade school  lette  man 

的perpos如果用这个数据来提取的统计信息,根据一些冒号:“学校,专业,性别”里的结果应为如下:

School   Specialty  Sex  number 
la roccade school letter  man   02 
la roccade school letter  women  00 
la roccade school science  man   00 
la roccade school science  women  01 
johara school  letter  man   01 
johara school  letter  women  00 
johara school  science  man   00 
johara school  science  women  01 
lever school  letter  man   00 
lever school  letter  women  00 
lever school  science  man   01 
lever school  science  women  00 

PS:数据量不固定。它可以改变的地方。

回答

1

你只是在寻找一个查询来获得想要的结果吗?这应该工作:

SELECT 
    School, 
    Specialty, 
    Sex, 
    COUNT(ID) AS Number 
FROM TAB1 
GROUP BY 
    School, 
    Specialty, 
    Sex; 
+0

它的工作很好,谢谢。现在的问题是显示这些数据。含义:仅显示第二个表中显示的列:_“学校,专业,性别”_。以及创建一个名为_“numbers”_的新列来显示统计信息。非常感谢你。 –