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[英]how to add a check in Java code for fetching only non-negative values from result-set
[英]how to add values from a MySQL result-set while loop in java?
我想通過使用while循環迭代結果集來添加從MySQL db獲得的整數列“ priority”的值。 我的代碼如下:
int TotalWestPriority = 0;
int WestPty = 0;
float lat = 0;
float lon = 0;
float Wb_SWLat = 0; // Currently holds some value from other process
float Wb_NELat = 0; // Currently holds some value from other process
float Wb_SWLon = 0; // Currently holds some value from other process
float Wb_NELon = 0; // Currently holds some value from other process
//SQL Query:
String qryVcl = "select priority, latitude, longitude from tbl_vcl";
ResultSet Vp=stmt.executeQuery(qryVcl);
while(Vp.next()){
lat = Vp.getFloat("latitude");
lon = Vp.getFloat("longitude");
System.out.println("Total Lat received:"+lat);
if(lat >=Wb_SWLat && lat <=Wb_NELat && lon>=Wb_SWLon && lon<=Wb_NELon){
WestPty = Vp.getInt("priority");
System.out.println("West Priority:"+WestPty);
}
}
在這里,我可以打印結果:
西部優先:3
西部優先:2
我想將這些值相加並存儲為整數。
如何將迭代中的所有“ westpty”添加到“ TotalWestPriority”?
只需將它們累加到另一個變量中:
long total = 0L;
while (vp.next()) {
lat = vp.getFloat("latitude");
lon = vp.getFloat("longitude");
if (lat >= Wb_SWLat && lat <= Wb_NELat &&
lon >= Wb_SWLon && lon <= Wb_NELon) {
westPty = Vp.getInt("priority");
System.out.println("West Priority:"+WestPty);
total += westPty;
}
}
System.out.println("Total west priority: " + total);
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