Question

我希望选择一个表的子集

然后我想计算这个子集中的记录数

最后得到一个特定字段的总和

我的代码如下： -

// get the subset of records in the XXXXXX table
ps = conn.prepareStatement("SELECT Field1, Field2, Field3 FROM XXXXXXX " 
    + "WHERE Field1 = ? AND Field2 = ? AND Field3 = ? "
    + "GROUP BY Field1, Field2, Field3");
ps.setString(1, variable1);
ps.setString(2, variable2);
ps.setString(3, variable3);
rs = ps.executeQuery(); 

int recordCount1 = 0;
while (rs.next()) {
recordCount1 = recordCount1 + rs.getInt(1);
}

rs.close();
ps.close(); 

myConsole.getOut().println("Number of records in Subset1 of table
   XXXXXXX: " + recordCount1);

// now split the subset into those records where P/L > 0  
and those records where P/L <0 
// positive P/L
ps = conn.prepareStatement("SELECT Field1, Field2, Field3 "
    + "SUM(PL) AS Total_Profit FROM XXXXXX "
    + "WHERE Field1 = ? AND Field2 = ? AND Field3 = ? "
    + "AND PL >= 0 "
    + "GROUP BY Field1, Field2, Field3");
ps.setString(1, variable1);
ps.setString(2, variable2);
ps.setString(3, variable3);
rs = ps.executeQuery(); 

int recordCount2a = 0;
while (rs.next()) {
recordCount2a = recordCount2a + rs.getInt(1);
}

myConsole.getOut().println("Number of records in Subset of table
XXXXXX where P/L >= 0: " + recordCount2a);

我对子集

中的记录数进行零计数

代码区域是否有错误？

Answer 1

首先查询。 - ＆GT;显示计数FIELD1

SELECT FIELD1, COUNT(FIELD1) FROM XXXXX
WHERE FIELD1= ? AND FIELD2=? AND FIELD3=?
GROUP BY FIELD1

第二个查询 - ＆gt;显示FIELD1的计数及其PL SUM

SELECT FIELD1, COUNT(FIELD1), SUM(PL) AS Total_Profit FROM XXXXX
WHERE FIELD1= ? AND FIELD2=? AND FIELD3=? AND PL > 0
GROUP BY FIELD1

sql表的子集 - 记录数和字段总和

1 个答案: