// query NO starts at 0
// queryNoNext starts at 1
// depth starts at 0
// DataObj d - data object that's foreign keys are being expanded from ids to JSON objects
// depth - tab placement
// queryNo - which query is currently
public String evaluateFK(
DataObj d, int depth, String lastQueryFrom, String lastQueryWhere, String dbQueryParam) {
StringBuilder s = new StringBuilder(4028);
HashMap<DataObj, List<String>> dataObjsMap = new HashMap<DataObj, List<String>>();
// First, evaluate all the foreign keys on the current object
for (Field f : d.getFields()) {
if (f.getType() == Field.Type.FOREIGN_KEY) {
// get the object corresponding to the foreign key field str
// so that you know what fields to get in sql statement
for (DataObj fkObj : d.getDependencies()) {
if ((fkObj.getName()).equals(f.getTypeStr())) {
String parentRow = "rows" + Integer.toString(queryNo);
String fkRow = "rows" + Integer.toString(queryNoNext);
String fkName = fkObj.getName();
String parName = d.getName();
// The 'from' part of a SQL select FROM where
String queryFrom = lastQueryFrom + " " + fkName + " as " + fkName + " ";
// The 'where' part of a SQL select from WHERE
String queryWhere =
lastQueryWhere + " " + fkName + ".id = " + parName + "." + f.getName();
// Recursive calls do need this text
if (queryNo == 0) {
queryFrom += " inner join " + parName + " as " + parName + " ";
queryWhere += " and " + parName + ".id = ?";
}
if (depth == 0) {
s.append(returnTab(2 + depth) + "totalCount += rows0.length;\n");
}
s.append(returnTab(2 + depth) + parentRow + ".forEach(function(row) { \n");
s.append(returnTab(3 + depth) + "query = \"" + selectProperties(fkObj) + "\";\n");
s.append(returnTab(3 + depth) + "query += \"from " + queryFrom + "\";\n");
s.append(returnTab(3 + depth) + "query += \"where " + queryWhere + "\";\n");
s.append(
returnTab(3 + depth)
+ "con.query(query, "
+ dbQueryParam
+ ", function(err, "
+ fkRow
+ ",fields) {\n");
s.append(returnTab(4 + depth) + "if (err) throw err;\n");
s.append(returnTab(4 + depth) + "row." + f.getName() + " = " + fkRow + "[0];\n");
// Store this object, so below you can check if it has
// foreign keys that have to be evaluated
ArrayList<String> a = new ArrayList<String>();
a.add(queryFrom + " inner join ");
a.add(queryWhere + " and ");
a.add(Integer.toString(queryNoNext));
dataObjsMap.put(fkObj, a);
depth += 2;
queryNoNext++;
break;
}
}
}
}
// Second, recursively evaluate all of the foreign key objects
// The keys of dataObjsMap are all of the objects that are
// DataObj d's object dependencies
// The value is an array [0] - queryFrom
// [1] - queryWhere
// [2] - queryNo
// The dataObjsMap is populated roughly 10 lines up
Iterator it = dataObjsMap.entrySet().iterator();
while (it.hasNext()) {
Map.Entry one = (Map.Entry) it.next();
DataObj key = (DataObj) one.getKey();
List<String> values = (List<String>) dataObjsMap.get(key);
// reset global variable queryNo
// why are we parsing ints? Need to parse the int because
// [2] queryNo is an int
queryNo = Integer.parseInt(values.get(2));
s.append(
evaluateFK(key, depth, (String) values.get(0), (String) values.get(1), dbQueryParam));
}
if (depth > tabDepth) {
tabDepth = depth;
}
return s.toString();
}
