GreenDao whereOr and conditions adding in a loop - java

I need to add some or clauses to query. I need to do it in a loop.
StringTokenizer st = new StringTokenizer(symptoms, ",");
while(st.hasMoreTokens()){
qb.whereOr(Properties.Symptom.like("%" + st.nextToken() + "%"));
}
How I can add those or conditions properly, because this above is not working as expected. I want to add or for every symptom.

If you look at the documentation, you'll see that whereOr() takes an unbounded number of conditions. What you want to do is add them all at once in an array:
StringTokenizer st = new StringTokenizer(symptoms, ",");
ArrayList<WhereCondition> whereConditions = new ArrayList<WhereCondition>();
while(st.hasMoreTokens()){
whereConditions.add(Properties.Symptom.like("%" + st.nextToken() + "%"));
}
// Give the ArrayList an already allocated array to place its contents in.
WhereCondition[] conditionsArray = new WhereCondition[whereConditions.size()];
conditionsArray = whereConditions.toArray(conditionsArray);
qb.whereOr(conditionsArray);
It looks like the method call in the documentation takes two non-array WhereConditions and then an ellipsized argument, which accepts an array or an additional comma-separated list of objects. So you might have to do something like this to get it to work properly:
qb.whereOr(conditionsArray[0], conditionsArray[1], Arrays.copyOfRange(conditionsArray, 2, conditionsArray.length));
ADDENDUM: It looks like you're using APIs that don't match the documentation, possibly an older version of greenDAO. I wrote this solution based off the current documentation. I can't guarantee that it will work for you. I recommend updating if possible.

Try this:
StringTokenizer st = new StringTokenizer(symptoms, ",");
WhereCondition where = null;
while(st.hasMoreTokens()){
if (where != null) {
where = qb.or(where, Properties.Symptom.like("%" + st.nextToken() + "%"));
} else {
where = Properties.Symptom.like("%" + st.nextToken() + "%");
}
}
qb.where(where).list();

I had the same problem so I added my own method in an Util class to perform the same behavior when I have one or several WhereCondition in an array.
Here is my gateway method :
public static QueryBuilder whereOr(QueryBuilder queryBuilder, WhereCondition[] whereConditions){
if(whereConditions == null) return queryBuilder.where(null);
else if(whereConditions.length == 1) return queryBuilder.where(whereConditions[0]);
else return queryBuilder.whereOr(whereConditions[0], whereConditions[1], Arrays.copyOfRange(whereConditions, 2, whereConditions.length));
}
Use : Util.whereOr(queryBuilder, whereConditionsArray);
Default : Can't use the Builder Pattern from the QueryBuilder with this approach
(More later) Here, I share you some code which could spare you time when developping DAO methods.
public class QueryBuilderUtil {
public static final String EQ = "=?";
public static final String NOTEQ = "<>?";
public static final String LIKE = " LIKE ?";
public static final String GE = ">=?";
public static final String LE = "<=?";
public static final String GT = ">?";
public static final String LT = "<?";
public static QueryBuilder whereOrOnSamePropertyWithDifferentValues(QueryBuilder queryBuilder, Property property, String operation, String values, String separator) {
return whereOrOnSamePropertyWithDifferentValues(queryBuilder, property, operation, values.split(separator));
}
public static QueryBuilder whereOrOnSamePropertyWithDifferentValues(QueryBuilder queryBuilder, Property property, String operation, String[] values) {
WhereCondition[] whereConditions = new WhereCondition[values.length];
int i = 0;
for (String value : values) {
whereConditions[i++] = new WhereCondition.PropertyCondition(property, operation, value);
}
return whereOr(queryBuilder, whereConditions);
}
public static QueryBuilder whereOr(QueryBuilder queryBuilder, WhereCondition[] whereConditions) {
if (whereConditions == null) return queryBuilder.where(null);
else if (whereConditions.length == 1) return queryBuilder.where(whereConditions[0]);
else return queryBuilder.whereOr(whereConditions[0], whereConditions[1], Arrays.copyOfRange(whereConditions, 2, whereConditions.length));
}
}
With this class, you can perform a whereOr with the same property on multiples "values string" in one line. It was necessary to clean my code :). However you can only do simple operations like variables declared in the class.
Example :
public List<Block> loadAllByModId(String mods_id) {
synchronized (this) {
QueryBuilder<Block> queryBuilder = queryBuilder();
QueryBuilderUtil.whereOrOnSamePropertyWithDifferentValues(queryBuilder, Properties.ModId, QueryBuilderUtil.EQ, mods_id, ";");
query_list = queryBuilder.build();
}
Query<Block> query = query_list.forCurrentThread();
return query.list();
}
Hope it helps

Related

Room database RawQuery() is not work on "IN" and "NOT IN" clause

I have my one table like UserTable.
#Entity
public class UserTable{
#PrimaryKey(autoGenerate = true)
private int userId;
private String userName;
private String userEmailId;
// Below code is getter and setter of this class.
}
#Dao
public interface UserDao {
#Query("SELECT * FROM userTable")
public List<UserTable> loadAllUsers();
#Insert
public long insertUserTable(UserTable userTable);
#Insert
public long[] insertUserTables(UserTable... userTables);
#Update
public int updateUserTable(UserTable userTable);
#Delete
public int deleteUserTable(UserTable userTable);
#RawQuery
public abstract List<UserTable> loadAllUserListByGivenIds
(SupportSQLiteQuery query);
public default List<UserTable> loadAllUserListByIds(long[] userIds) {
List<UserTable> list;
ArrayList<Object> argsList = new ArrayList<>();
String selectQuery = "SELECT * FROM UserTable WHERE userId IN (?);";
argsList.add(userIds);
SimpleSQLiteQuery simpleSQLiteQuery = new SimpleSQLiteQuery(selectQuery, argsList.toArray());
list = loadAllUserListByGivenIds(simpleSQLiteQuery);
return list;
}
}
// Now in My MainActivity.class file, I have use following code:
List<UserTable> userList= databaseClient
.getAppDatabase()
.userDao()
.loadAllUserListByIds(new long[]{1L,2L});
My query is running in normal database, but when I was pass array of user ids then, in #RawQuery() method of dao class is not supported for "IN" clause used in where condition "WHERE userId IN (?)".
How, I will use "IN" clause in #RawQuery() of room database.
Much easier to use an #Query it's as simple as:-
#Query("SELECT * FROM UserTable WHERE userId IN (:idList)")
public List<UserTable> getWhatever(long[] idList);
You'd then use getWhatever(new long[]{1L,2L})
If you need it an #rawQuery though you could do it like (used previous answer code for my convenience) :-
private List<TableXEntity> loadAllUserListByIds(int order,long[] idList) {
StringBuilder idListAsCSV = new StringBuilder(); //<<<<<<<<<<
boolean afterFirst = false; //<<<<<<<<<<
//<<<<<<<<<< all of the loop to create the CSV
for (Long l: idList) {
if (afterFirst) {
idListAsCSV.append(",");
}
afterFirst = true;
idListAsCSV.append(String.valueOf(l));
}
StringBuilder sb = new StringBuilder("SELECT * FROM ").append(DBHelper.TableX.NAME);
sb.append(" WHERE " + DBHelper.TableX.COLUMN_ID + " IN(").append(idListAsCSV).append(") "); //<<<<<<<<<<
switch (order) {
case DBHelper.TableX.FIRSTNAME_DESCENDING:
sb.append(DBHelper.TableX.ORDER_BY_FIRSTNAME_DESC);
break;
case DBHelper.TableX.FIRSTNAME_ASCENDING:
sb.append(DBHelper.TableX.ORDER_BY_FIRSTNAME_ASC);
break;
case DBHelper.TableX.LASTNAME_DESCENDING:
sb.append(DBHelper.TableX.ORDER_BY_LASTNAME_DESC);
break;
case DBHelper.TableX.LASTNAME_ASCENDING:
sb.append(DBHelper.TableX.ORDER_BY_LASTNAME_ASC);
break;
default:
break;
}
sb.append(";");
return roomDao.rawq(new SimpleSQLiteQuery(sb.toString(),null));
}
i.e. provide a CSV (although I vaguely recall being able to pass an array)
To use bind arguments (the recommended way as binding arguments protects against SQL injection) then you need a ? for each value and a corresponding array of objects.
So for 3 id's you need IN(?,?,?) and the actual values, the bind arguments, in an Object[]. The following is an example that does this noting that it shows 2 ways of building the Object[] (the bind arguments/values):-
private List<TableXEntity> loadByidList(long[] idlist) {
List<Object> bindargs = new ArrayList<>(); // way 1
Object[] args4Bind = new Object[idlist.length]; // way 2
StringBuilder placeholders = new StringBuilder(); // for the ? placeholders
/* Build the sql before the place holders */
StringBuilder sql = new StringBuilder("SELECT * FROM ")
.append(DBHelper.TableX.NAME)
.append(" WHERE ")
.append(DBHelper.TableX.COLUMN_ID)
.append(" IN (");
boolean afterfirst = false;
int i = 0; /* using for each so have index counter (as opposed to for(int i=0 ....) */
for (long l: idlist) {
bindargs.add(l); // for way 1
args4Bind[i++] = String.valueOf(l); // for way 2
if (afterfirst) {
placeholders.append(",");
}
afterfirst = true;
placeholders.append("?");
}
/* finalise the SQL */
sql.append(placeholders.toString())
.append(");");
//return roomDao.rawq(new SimpleSQLiteQuery(sql.toString(),bindargs.toArray())); // way 1
return roomDao.rawq(new SimpleSQLiteQuery(sql.toString(),args4Bind)); // way 2
}
Please try this, here it has working!
Try this simple trick to pass the arguments for IN operator-
List<Object> argList = new ArrayList<>();
argList.add("3");
argList.add("6");
Then prepare your raw query string:
Note- Match your argument list size with '?' size
String selectQuery = "SELECT * FROM task WHERE id IN (?,?)";
After this pass the raw query string to SimpleSQLiteQuery-
SimpleSQLiteQuery rawQuery = new SimpleSQLiteQuery(selectQuery, args.toArray());
Then fetch the List using DAO:
List<UserTable> taskList1=DatabaseClient
.getInstance(getApplicationContext())
.getAppDatabase()
.userTableDAO()
.getAllList(query);
We can do it in kotlin in the more simpler way.
Let's create two helper methos
object Helper {
fun sqlIn(list: List<Any>, bindArgs: MutableList<Any>): String {
bindArgs.apply { this.addAll(list) }
return "IN (${list.joinToString(",") { "?" }})"
}
fun sqlNotIn(list: List<Any>, bindArgs: MutableList<Any>): String = "NOT ${sqlIn(list, bindArgs)}"
}
Then you can use it in anywhere else
val ids = listOf(1, 2, 3)
val ownerId = 10
val bindArgs = mutableListOf<Any>()
val query = "SELECT * FROM posts WHERE id ${Helper.sqlIn(ids, bindArgs)} AND owner_id = ?"
bindArgs.add(ownerId)
dao.query(
SimpleSQLiteQuery(query, bindArgs.toTypedArray())
)

Can we Replace a portion of String in Java which has symbol in the start and end to Identify?

I have a String SELECT *FROM USERS WHERE ID = '#userid#' AND ROLE = '#role#'
Now i have replace any string between #...# , with a actual value .
Expected output SELECT *FROM USERS WHERE ID = '4' AND ROLE = 'Admin'
This replace will happen from a method , i have written this logic
public String replaceQueryKeyWithValueFromKeyValues(String query, int reportId) {
try {
REPMReportDao repmReportDao = new REPMReportDao();
int Start = 0;
int end;
if (query.contains("#")) {
boolean specialSymbolFound = false;
for (int i = 0; i < query.length(); i++) {
if (query.charAt(i) == '#') {
if (!specialSymbolFound) {
Start = i + 1;
specialSymbolFound = true;
} else {
specialSymbolFound = false;
end = i;
query = query.replace(query.substring(Start - 1, end + 1), repmReportDao.getReportManagerKeyValue(query.substring(Start - 1, end + 1).replaceAll("#", ""), reportId));
}
}
}
return query;
} else {
return query;
}
} catch (Exception e) {
logger.log(Priority.ERROR, e.getMessage());
return e.getMessage();
}
}
It works fine , but in the case if a single '#' symbol exist instead of start and end it will fail.
Like :
SELECT *FROM USERS WHERE emailid = 'xyz#gmail.com' AND ROLE = '#role#'
Here it should replace the only role '#role#' and should left email as it is.
Expected Output => SELECT *FROM USERS WHERE emailid = 'xyz#gmail.com' AND ROLE = 'Admin'
Complete example with mocked data returned by getReportManagerKeyValue:
import java.util.HashMap;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class StackOverflow54842971 {
private static Map<String, String> map;
public static void main(String[] args) {
// preparing test data
map = new HashMap<>();
map.put("role", "Admin");
map.put("userid", "666");
// original query string
String query = "SELECT * FROM USERS WHERE ID = '#userid#' AND emailid = 'xyz#gmail.com' AND ROLE = '#role#' ";
// regular expression to match everything between '# and #' with capture group
// omitting single quotes
Pattern p = Pattern.compile("'(#[^#]*#)'");
Matcher m = p.matcher(query);
while (m.find()) {
// every match will be replaced with value from getReportManagerKeyValue
query = query.replace(m.group(1), getReportManagerKeyValue(m.group(1).replaceAll("#", "")));
}
System.out.println(query);
}
// you won't need this function
private static String getReportManagerKeyValue(String key) {
System.out.println("getting key " + key);
if (!map.containsKey(key)) {
return "'null'";
}
return map.get(key);
}
}
It's considered very bad practice to use string substitution to generate database queries, because you leave your code open to SQL Injection attacks. I can't tell from the small code sample you've provided, but the vast majority of large-scale Java projects use the Spring Framework, which allows you to use either JdbcTemplate or (my preference) NamedParameterJdbcTemplate. Both will allow you to substitute variables in a safe manner.

Replace a variable in a String

I am looking for a String Utils so that I can do something like this.
String input = "this is the $var on $date"
someUtil.evaluate(input, [var: "end", date: "11/11/11"])
output : this is the end on 11/11/11.
someUtil.evaluate(input, [var: "start", date: "10/10/10"])
output : this is the start on 10/10/10.
Use standard java MessageFormat, it is quite powerfull (read its class level JavaDoc)
Date endDate = new GregorialCalendar(2011, Calendar.NOVEMBER, 11).getTime();
...
MessageFormat.format(
"this is the {0} on {1,date,yy/MM/dd}",
new Object[]{"end", endDate});
Do you really need as incoming parameter that "array" ? If not, that you can implement as easy as it is ..
private static String replaceVarByVal(String toReplace,String var,String val){
return toReplace.replace(var, val);
}
(You can easy modify that to incom params arrays, but better should be eg. Map- key variable, value new value of the "placeholder" - $var)
Arrays variant:
private static String replaceVarByVal(String toReplace,String[] var,String[] val){
String toRet = toReplace;
//arrays logic problem
if(var.length != val.length){
return null;
}else{
for (int i = 0; i < var.length; i++) {
toRet = toRet.replace(var[i], val[i]);
}
}
return toRet;
}
Better variant with map:
private static String replaceVarByVal(String toReplace,Map<String, String> paramValsMap){
String toRet = toReplace;
for (Map.Entry<String, String> entry : paramValsMap.entrySet())
{
toRet=toRet.replace(entry.getKey(), entry.getValue());
}
return toRet;
}
(And that can be used universally for anything)

Lucene wrong match

I have a csvfile
id|name
1|PC
2|Activation
3|USB
public class TESTResult
{
private Long id;
private String name;
private Float score;
// with setters & getters
}
public class TEST
{
private Long id;
private String name;
// with setters & getters
}
public class JobTESTTagger {
private static Version VERSION;
private static CharArraySet STOPWORDS;
private static RewriteMethod REWRITEMETHOD;
private static Float MINSCORE = 0.0001F;
static {
BooleanQuery.setMaxClauseCount(100000);
VERSION = Version.LUCENE_44;
STOPWORDS = StopAnalyzer.ENGLISH_STOP_WORDS_SET;
REWRITEMETHOD = MultiTermQuery.CONSTANT_SCORE_FILTER_REWRITE;
}
public static ArrayList<TESTResult> searchText(String text, String keyId,
List<TEST> TESTs) {
ArrayList<TESTResult> results = new ArrayList<TESTResult>();
MemoryIndex index = new MemoryIndex();
EnglishAnalyzer englishAnalyzer = new EnglishAnalyzer(VERSION,STOPWORDS);
QueryParser parser = new QueryParser(VERSION, "text", englishAnalyzer);
parser.setMultiTermRewriteMethod(REWRITEMETHOD);
index.addField("text", text, englishAnalyzer);
for (int i = 0; i < TESTs.size(); i++) {
TEST TEST = TESTs.get(i);
String criteria = "\"" + TEST.getName().trim() + "\"";
if (criteria == null || criteria.isEmpty())
continue;
criteria = criteria.replaceAll("\r", " ");
criteria = criteria.replaceAll("\n", " ");
try {
Query query = parser.parse(criteria);
Float score = index.search(query);
if (score > MINSCORE) {
int result = new TESTResult(TEST.getId(), TEST.getName(),score);
results.add(result);
}
} catch (ParseException e) {
System.out.println("Could not parse article.");
}
}
return results;
}
public static void main(String[] args) {
ArrayList<TESTResult> testresults = searchText(text, keyId, iths);
CsvReader reader = new CsvReader("C:\a.csv");
reader.setDelimiter('|');
reader.readHeaders();
List<TEST> result = new ArrayList<TEST>();
while (reader.readRecord()) {
Long id = Long.valueOf(reader.get("id").trim());
String name = reader.get("name").trim();
TEST concept = new TEST(id, name);
result.add(concept);
}
String text = "These activities are good. I have a good PC in my house.";
}
I am matching 'activities' to Activation. How is it possible. Can anybody tell me how Lucene matches the words.
Thanks
R
EnglishAnalyzer, along with most language-specific analyzers, uses a stemmer. This means that it reduces terms to a stem (or root) of the term, in order to attempt to match more loosely. Mostly this works well, removing suffixes and matching up derived words to a common root. So when I search for "fish", I also find "fished", "fishing" and "fishes".
In this case though, both "activities" and "activation" both reduce to the root of "activ", resulting in the match you are seeing. Another example: "organ", "organic" and "organize" all have the common stem "organ".
You can stem or not, neither approach is perfect. If you don't stem you'll miss relevant results. If you do, you'll hit some odd irrelevant results.
To deal with specific problematic cases, you can define a stemmer exclusion set in EnglishAnalyzer to prevent stemming just on those specific problematic terms. In this case, I would think of "activation" as the probable term to prevent stemming on, though you could go either way. So I could do something like:
CharArraySet stemExclusionSet = new CharArraySet(VERSION, 1, true);
stemExclusionSet.add("activation");
EnglishAnalyzer englishAnalyzer = new EnglishAnalyzer(VERSION, STOPWORDS, stemExclusionSet);

How to generate a sql from the inputs to the method

I have my below method which will accept two parameters-
final String userId- Primary Key for the database
final Collection<String> attributeNames- list of column names that I
want to retrieve
Below is the code
public Map<String, String> getAttributes(final String userId, final Collection<String> attributeNames) {
//Below line doesn't works out the way I wanted
String query="SELECT" +attributeNames.toString()+ ", * from test where id = "+userId+ ";";
ResultSet result = CassandraDatastaxConnection.getInstance().getSession().execute(query);
for (Row rows: result){
System.out.println(rows.getString("key"));
}
return attributes;
}
let's take an example, userId as 40
Sample attributeNames will look like this-
[account, behavior, segmentation]
Now I need to generate a SQL corresponding to the inputs. So for above example, sql should look like this-
SELECT account, behavior, segmentation from test where id = "40";
How can I generate a SQL like this from the above inputs? Thanks for the help.
You can use something like attributeNames.toString().substring(1, attributeNames.toString().length()-1)
Change this function
public Map<String, String> getAttributes(final String userId, final Collection<String> attributeNames) {
//Below line doesn't works out the way I wanted
String query="SELECT" +attributeNames.toString()+ ", * from test where id = "+userId+ ";";
ResultSet result = CassandraDatastaxConnection.getInstance().getSession().execute(query);
for (Row rows: result){
System.out.println(rows.getString("key"));
}
return attributes;
}
to this
public Map<String, String> getAttributes(final String userId, final Collection<String> attributeNames) {
//Below line doesn't works out the way I wanted
StringBuilder sb = new StringBuilder(attributeNames.size());
for(int i = 0; i<attributeNames.size();i++)
{
sb.append(attributeNames.get(i));
if(i != attributeNames.size() - 1)
sb.append(",");
}
String query="SELECT" +sb.toString()+ " from test where id = "+userId+ ";";
ResultSet result = CassandraDatastaxConnection.getInstance().getSession().execute(query);
for (Row rows: result){
System.out.println(rows.getString("key"));
}
return attributes;
}
The modified function runs a loop through the attribute names and constructs the query part as name1, name2, name3, etc and then adds it to the query body. Hope this solves your problem.

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