I'm creating an app in android studio and i have some questions stored in a database which is created when the user opens the app for the first time and i created another database so the user can add his questions and i need to take a random question from out of these 2 databases.Each database have 3 same columns 1.question 2.heat 3.gender
Here's what i already tried but don't work.
public Cursor getQuestion(int HeatLevel, int Gender) {
SQLiteDatabase db = this.getWritableDatabase();
String query = "SELECT question, heat, gender FROM " + TABLE_NAME +
" WHERE heat = " + HeatLevel + " AND gender = " + Gender +
" UNION ALL" +
" SELECT question, heat, gender FROM " + SECOND_TABLE_NAME +
" WHERE heat = " + HeatLevel + " AND gender = " + Gender +
" ORDER BY RANDOM() LIMIT 1";
Cursor data = db.rawQuery(query, null);
return data;
}
So the app chooses a question from the database based on the difficulty and the players gender.
The above code produces an error saying "No such table" and the name of the second database like it can't find it.
i get the question in another activity using this
public void getQuestion(int HeatLevel, int Gender) {
Cursor question = QuestionDB.getQuestion(HeatLevel, Gender);
if (question.moveToNext()) {
QuestionTextView.setText(question.getString(0));
}
}
I'm new to sql so maybe the query is wrong.
Related
I am trying to fetch a record from the sqlite database in Android, and having trouble. It often throws java.lang.IllegalArgumentException and gives me the same message.
mListSongs = mSongDao.getSelectedSongs(artist_id);
public List<Song> getSelectedSongs(Long artistId) {
List<Song> listSongs = new ArrayList<Song>();
String selectQuery = "SELECT " + DBHelper.SONG_PATH + " FROM " + DBHelper.TABLE_SONG + " s, "
+ DBHelper.TABLE_ARTIST + " a WHERE s."
+ DBHelper.SONG_ID + " = a.'" + DBHelper.ARTIST_ID + "'";
String[] selectionArgs = new String[]{String.valueOf(artistId)};
Cursor cursor;
cursor = mDatabase.rawQuery(selectQuery, selectionArgs);
cursor.moveToFirst();
while (!cursor.isAfterLast()) {
Song song = cursorToSelectSong(cursor);
listSongs.add(song);
cursor.moveToNext();
}
cursor.close();
return listSongs;
}
private Song cursorToSelectSong(Cursor cursor) {Song song = new Song(); song.setmSong_path(cursor.getString(3)); return song;}
The issue is that you are supplying an argument, as per String[] selectionArgs = new String[]{String.valueOf(artistId)}; and then cursor = mDatabase.rawQuery(selectQuery, selectionArgs); but that the statement (the SELECT statement) has no place-holder (an ?) within it.
So you have 1 argument but the statement has 0 parameters to substitute the argument for.
Changing :-
String selectQuery = "SELECT " + DBHelper.SONG_PATH + " FROM " + DBHelper.TABLE_SONG + " s, "
+ DBHelper.TABLE_ARTIST + " a WHERE s."
+ DBHelper.SONG_ID + " = a.'" + DBHelper.ARTIST_ID + "'";
to :-
String selectQuery = "SELECT " + DBHelper.SONG_PATH + " FROM " + DBHelper.TABLE_SONG + " s, "
+ DBHelper.TABLE_ARTIST + " a WHERE s."
+ DBHelper.SONG_ID + "=?";
Introduces the parameter and it, the ?, will be substituted for the artist_id passed to the method.
Alternately using :-
String selectQuery = "SELECT " + DBHelper.SONG_PATH + " FROM " + DBHelper.TABLE_SONG + " s, "
+ DBHelper.TABLE_ARTIST + " a WHERE s."
+ DBHelper.SONG_ID + " =" + String.valueOf(artist_id);
along with :-
cursor = mDatabase.rawQuery(selectQuery, null);
would also work BUT is open to SQL injection (but not really as it's a long that has been passed, which cannot be a String that could contain dangerous SQL).
i.e. no arguments are passed into rawQuery and therefore there is no expectation that the statement should contain a parameter place-holder (?).
However, there is no need to JOIN the ARTIST table as the SONG table has the ARTIST_ID column.
You'd only need the JOIN if you wanted other details about the ARTIST e.g. artist name (which you probably already know as you've ascertained the ARTIST_ID when invoking the method).
As such the simplified :-
String selectQuery = "SELECT " + DBHelper.SONG_PATH + " FROM " + DBHelper.TABLE_SONG + " WHERE " + DBHelper.SONG_ID + "=?";
would suffice.
Regarding Cursor issues I'd suggest trying :-
cursor = mDatabase.rawQuery(selectQuery, selectionArgs);
DatabaseUtils.dumpCursor(cursor); //<<<<<<<<<< will output the contents of the cursor to the log
while(cursor.moveToNext()) {
String songpath = cursor.getString(cursor.getColumnIndex(DBHelper.SONG_PATH));
Log.d("EXTRACTEDPATH", "Extracted PATH " + songpath); //<<<<<<<<<< output extracted path to the log
Song newsong = new Song();
newsong.setmSong_path(songpath);
listSongs.add(newsong);
}
cursor.close();
return listSongs;
}
Dumps the Cursor immediately after it is retrieved
Uses simpler loop
Uses column name to derive the column offset
outputs the data from the column (if it shows path in log, but you still get empty path in list then it's either setmSong_path that is wrong or how you are getting data from the List.)
I think you want to fetch a list of songs by an artist, providing the artistId.
I believe that in in each row of the songs table DBHelper.TABLE_SONG there is a column for the id of the artist. If there isn't it should be.
Change your sql statement to this:
String selectQuery = "SELECT " + DBHelper.SONG_PATH + " FROM " + DBHelper.TABLE_SONG + " WHERE " + DBHelper.ARTIST_ID + " = ?";
As I said there must be a column DBHelper.ARTIST_ID or similar to identify the artist of each song.
The ? is the 1 parameter and its value will be artistId.
(Edit: This is a question that I had and I answer it in the hopes of helping someone else who had a similar question.)
I am trying to clean up geographic data in my Google Fusion Table and would like to write a Java program to read in select Fusion Table rows, modify columns in each row and write out the modified rows back to the original fusion table.
I have found Christian Junk's example code in the Google API Client Libraries documentation: "fusiontables-cmdline-sample" that shows how to: Authorize access to a users fusion tables, list tables, create a table, insert data into a table, show rows, delete a table.
How do I modify this example to make updates to selected rows in a table? (see answer with code below)
[edit]: I didn't find any good solutions on the Net. I have written the solution in Java and will answer in the answers in the hope that it can help someone else how is trying to do this. I am a novice Java programmer so the code reflects that. I also needed to get nearby big cities based on a gps location and used GeoNames api (citiesJSON) creating a bounding box to do that. This solution uses JSON to access items returned from REST calls.
I have written a Java program that does the row data modification described in the question. It uses Christian Junk's example noted in the question and also calls GeoNames citiesJSON webservice as described in the question (sending bounding box coordinates in the parameters). I'm a novice in Java so the code is what it is. I do a lot of commenting in order to reuse code, like SQL queries, later.
You can find my solution on Github at: FusionTableModifyJava
The primary module of interest is: FusionTableSample.java
Here are the functions that do the getRows and updateRows. Everything else can be seen at github (by Microsoft$):
private static void getRows(String tableId) throws IOException {
View.header("Updating Rows From Table");
/*Sql sql = fusiontables.query().sql("SELECT RowID, 'Area Name', Notes, Number FROM " + tableId +
" Where Manager = '' AND 'Review 1' CONTAINS IGNORING CASE '.fs.' Order by Number ASC LIMIT 3000");*/
/*Sql sql = fusiontables.query().sql("SELECT RowID, 'Area Name', Notes, Number FROM " + tableId +
" Where 'Area Name' CONTAINS IGNORING CASE 'Tioga George' Order by Number ASC LIMIT 3000");*/
/*Sql sql = fusiontables.query().sql("SELECT RowID, 'Area Name', Notes, Number FROM " + tableId +
" Where 'Area Name' ='' Order by Number DESC LIMIT 2000");*/
/*Sql sql = fusiontables.query().sql("SELECT RowID, 'Area Name', Notes, Number FROM " + tableId +
" Where 'Area Name' CONTAINS 'X01' Order by Number DESC LIMIT 1"); */
/*AND 'City (nearest)' DOES NOT CONTAIN IGNORING CASE 'Mexico'*/
/*Sql sql = fusiontables.query().sql("SELECT RowID, 'Area Name', Notes, Number, Location FROM " + tableId +
" Where State = '' Order by Number DESC LIMIT 100");*/
/*Sql sql = fusiontables.query().sql("SELECT RowID, 'Area Name', Notes, Number, Location FROM " + tableId +
" Where State = 'BCS' Order by Number DESC LIMIT 100");*/
Sql sql = fusiontables.query().sql("SELECT RowID, 'Area Name', Notes, Number, Location, State, Codes FROM " + tableId +
" Where State = 'ID' AND 'City (nearest)' = '' Order by Number DESC LIMIT 100");
try {
Sqlresponse response = sql.execute();
// System.out.println(response.toPrettyString());
mylist = response.getRows();
} catch (IllegalArgumentException e) {
// For google-api-services-fusiontables-v1-rev1-1.7.2-beta this exception will always
// been thrown.
// Please see issue 545: JSON response could not be deserialized to Sqlresponse.class
// http://code.google.com/p/google-api-java-client/issues/detail?id=545
}
}
private static void updateRows(String tableId) throws IOException {
// IOException needed ParseException
count = 1;
mylist.forEach((myRow) -> {
try {
// modify fields in table...
//newAreaName = kt.firstpart(myRow.get(NOTES).toString()); //get Notes first sentence
//newAreaName = newAreaName.replace("'", "''");
//newAreaName += " X01";
//String state = getStateFrmLoc(myRow.get(LOCATION).toString());
//String state = "MX-BCS";
float km;
if ( "AK,MT,NV".contains(myRow.get(STATE).toString()) ) {
km = 180f; // 111.85 miles
} else {
km = 80.5f; // 50 miles
}
BigCity big = new BigCity(myRow.get(LOCATION).toString(), km);
String cityState = big.cityName +", "+big.state;
if (big.population < 10000f) {
System.out.println("Skip for low population :"+myRow.get(NUMBER));
} else {
sqlupdate = "UPDATE " + tableId + " " +
"SET 'City (nearest)' = '" + cityState + "' " +
",'Codes' = '" + myRow.get(CODES).toString() + ",#U1' " +
"WHERE ROWID = " + myRow.get(ROW_ID);
System.out.println("[" + count + "]" + myRow.get(NUMBER) + ": " + sqlupdate);
// do the update...
if (!mtest) { // if testing then don't update
sql_doupdate(sqlupdate);
}
count++;
if ((count % 30) == 0) {
System.out.println("waiting 60 seconds");
TimeUnit.SECONDS.sleep(60); //Fusion Tables allows 30 updates then must wait 1 minute.
}
}
} catch(Exception e){
System.out.println(e.getMessage());
}
});
}
I am trying to do two SQLite tables, one to enter data and another one to retrieve the calculated data.
First I want to let the client enter some REAL data and then calculate in the background and put the new data to the textview.
For now, I tried to retrieve it from one table.
#Override
public void onCreate(SQLiteDatabase db) {
String sSQL;
sSQL = "CREATE TABLE " + DataContract.TABLE_NAME +
"(" +
DataContract.Columns._ID + " INTEGER PRIMARY KEY NOT NULL, " +
DataContract.Columns.PRODUCT_NAME + " TEXT, " +
DataContract.Columns.PRODUCT_WIDTH + " REAL, " +
DataContract.Columns.PRODUCT_LENGHT+ " REAL, " +
DataContract.Columns.PRODUCT_PRICE+ " REAL, " +
//This is the data I want to calculate and put to a textview in a
//new intent
DataContract.Columns.PRODUCT_TOTAL_PRICE + " REAL)";
Log.d(TAG,sSQL);
db.execSQL(sSQL);
}
I have a Serializable class and I tried to calculate the data in this class.
private final String ProductName;
private final double ProductLenght;
private final double ProductWidth;
private final double ProductPrice;
private final double ProductTotalPrice;
Then I tried to calculate the data in getter method.
public double getProductTotalPrice() {
return (getProductWidth() * getProductLenght() * getProductPrice())/1000;
}
However, I dont know how to put retrieve the calculated data back to the textview.
Should I create two tables or one table is enough for this operation ?
And also what is the easiest way to calculate data inside Java code and put it back to a column ?
Thank you !
And also what is the easiest way to calculate data inside Java code
and put it back to a column ?
To do nothing (i.e. calculate the value when extracting the data and reduce the amount of data stored in the database)
To add another column for the calculated value would be a waste as you can calculate the value when extracting the data (into the cursor) e.g. :-
Assuming the table (called myproducts) is populated as follows (note no PRODUCT_TOTAL_PRICE column as it's not needed) :-
Then extracting it using the query :-
SELECT
_ID,
PRODUCT_NAME,
PRODUCT_WIDTH,
PRODUCT_LENGTH,
PRODUCT_PRICE,
(PRODUCT_WIDTH * PRODUCT_LENGTH * PRODUCT_PRICE)/1000 AS CALCULATED_TOTAL_PRICE
FROM myproducts;
Will result in :-
You could have a method in your Database Helper such as :-
public double Cursor getTotalpriceBtId(long id) {
double rv = 0;
String column_name = "totalprice";
String calculation = "(" +
DataContract.Columns.PRODUCT_WIDTH + " * " +
DataContract.Columns.PRODUCT_LENGHT + " * " +
DataContract.Columns.PRODUCT_PRICE + ")/1000";
String[] columns = new String[]{calculation + " AS " + column_name};
String whereclause = DataContract.Columns._ID + "=?";
String[] whereargs = new String[]{String.valueOf(id)};
Cursor csr = this.getWritableDatabase().query(
DataContract.TABLE_NAME,
columns,
whereclause,
whereargs,
null,null,null
);
if (csr.moveToFirst) {
rv = csr.getDouble(csr.getColumnIndex(column_name));
}
csr.close();
return rv;
}
The underlying SQL is similar to the example above. However, just the one column is needed.
However, I dont know how to put retrieve the calculated data back to
the textview.
Something along the lines of :-
yourTextView.setText(String.valueOf(yourDBHelperInstance.getTotalpriceBtId(ID_OF_THE PRODUCT)));
or perhaps :-
yourTextView.setText(String.valueOf(yourproduct.getProductTotalPrice()));
No need to create two tables
after inserting the value into table you just create a function by below query
select sum(your column name) from yourtablename where condition on which basis you filter the data.
I'm having an issue with my app.
What my app does is this : gets some data from a couple of edittexts(3 per row,created dynamically) and puts them in a database .
What i want the database to do is this : take the product name,the quantity and the price and put them in the table.The name should be UNIQUE(it will be used to power an autocomplete,it needs to be unique not to have duplicates in the AC list).The price in the database must be the last price inserted for that product(for example,if Cheese at 3$ is inserted and after that Cheese at 2.5$ in the database we will find 2.5$).The quantity has to be summed up(if i enter Cheese in quantity 3 and then again Cheese in quantity 4 in the database we will find 7).
Now,my issue : Lets say i enter this in my shopping list :
1. Hhhh 4 2.5
2. Dddd 3 1
3. Eeee 2 2
4. Aaaa 5 3.5
In my database I will find this :
4. Aaaa 4 2.5
2. Dddd 3 1
3. Eeee 2 2
1. Hhhh 5 3.5
So,the issue is that it arranges the product name column alphabetically but the other columns remain in the same order,the one i entered in the edittexts.
I did some tests,if i remove the UNIQUE from the product name column,it will enter it as it should but of course,it will create duplicates,which i don't need.I don't get it,what's wrong ? why does UNIQUE trigger this ?
Here's my code :
My table creation :
public class SQLiteCountryAssistant extends SQLiteOpenHelper {
private static final String DB_NAME = "usingsqlite.db";
private static final int DB_VERSION_NUMBER = 1;
private static final String DB_TABLE_NAME = "countries";
private static final String DB_COLUMN_1_NAME = "country_name";
private static final String DB_COLUMN_2_NAME = "country_counter";
private static final String DB_COLUMN_3_NAME = "country_price";
private static final String DB_CREATE_SCRIPT = "create table "
+ DB_TABLE_NAME
+ " (_id INTEGER PRIMARY KEY,country_name text unique, country_quantity REAL DEFAULT '0',country_price REAL);) ";
private SQLiteDatabase sqliteDBInstance = null;
public SQLiteCountryAssistant(Context context) {
super(context, DB_NAME, null, DB_VERSION_NUMBER);
}
#Override
public void onCreate(SQLiteDatabase sqliteDBInstance) {
Log.i("onCreate", "Creating the database...");
sqliteDBInstance.execSQL(DB_CREATE_SCRIPT);
}
My insert method :
public void insertCountry(String countryName, String countryPrice,
String countryQuantity) {
sqliteDBInstance.execSQL("INSERT OR IGNORE INTO " + DB_TABLE_NAME
+ "(country_name, country_quantity, country_price) VALUES('"
+ countryName + "','0', '" + countryPrice + "')");
sqliteDBInstance.execSQL("UPDATE " + DB_TABLE_NAME
+ " SET country_name='" + countryName
+ "', country_quantity=country_quantity+'" + countryQuantity
+ "' WHERE country_name='" + countryName + "';");
sqliteDBInstance.execSQL("UPDATE " + DB_TABLE_NAME
+ " SET country_name='" + countryName + "', country_price='"
+ countryPrice + "' WHERE country_name='" + countryName + "';");
}
And this is how i call the insert method :
for (int g = 0; g < allcant.size() - 1; g++) {
if (prod[g] != "0.0") {
sqlliteCountryAssistant.insertCountry(prod[g],pret[g],cant[g]);
}
Also,please excuse my messy code,i've started learning android with no programming background like a month ago.I just got my bachelors degree in Sociology so yea,i'm an absolute beginner.If there is way to do it better then i did and i'm pretty sure there is,please,show me the way,heh.
Thanks and have a good day !
EDIT : Aaaand the whole db class :
public class SQLiteCountryAssistant extends SQLiteOpenHelper {
private static final String DB_NAME = "usingsqlite.db";
private static final int DB_VERSION_NUMBER = 1;
private static final String DB_TABLE_NAME = "countries";
private static final String DB_COLUMN_1_NAME = "country_name";
private static final String DB_COLUMN_2_NAME = "country_counter";
private static final String DB_COLUMN_3_NAME = "country_price";
private static final String DB_CREATE_SCRIPT = "create table "
+ DB_TABLE_NAME
+ " ( id INTEGER PRIMARY KEY AUTOINCREMENT,country_name text unique, country_quantity REAL DEFAULT '0',country_price REAL)";
private SQLiteDatabase sqliteDBInstance = null;
public SQLiteCountryAssistant(Context context) {
super(context, DB_NAME, null, DB_VERSION_NUMBER);
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// TODO: Implement onUpgrade
}
#Override
public void onCreate(SQLiteDatabase sqliteDBInstance) {
Log.i("onCreate", "Creating the database...");
sqliteDBInstance.execSQL(DB_CREATE_SCRIPT);
}
public void openDB() throws SQLException {
Log.i("openDB", "Checking sqliteDBInstance...");
if (this.sqliteDBInstance == null) {
Log.i("openDB", "Creating sqliteDBInstance...");
this.sqliteDBInstance = this.getWritableDatabase();
}
}
public void closeDB() {
if (this.sqliteDBInstance != null) {
if (this.sqliteDBInstance.isOpen())
this.sqliteDBInstance.close();
}
}
public void insertCountry(String countryName, String countryPrice,
String countryQuantity) {
ContentValues cv = new ContentValues();
cv.put("country_name", countryName);
cv.put("country_price", countryPrice);
sqliteDBInstance.insertWithOnConflict(DB_TABLE_NAME, null, cv, sqliteDBInstance.CONFLICT_IGNORE);
// Increment the quantity field (there isn't a good way to do this with sql.update() )
sqliteDBInstance.execSQL("UPDATE " + DB_TABLE_NAME + " SET country_quantity=country_quantity+? WHERE country_name=?",
new Object[] { new Long(countryQuantity), countryName });
/*sqliteDBInstance.execSQL("INSERT OR IGNORE INTO " + DB_TABLE_NAME
+ "(country_name) VALUES('" + countryName + "')");
sqliteDBInstance.execSQL("UPDATE " + DB_TABLE_NAME
+ " SET country_quantity=country_quantity+" + countryQuantity
+ " WHERE country_name='" + countryName + "';");
sqliteDBInstance.execSQL("UPDATE " + DB_TABLE_NAME
+ " SET country_price=" + countryPrice
+ " WHERE country_name='" + countryName + "';");*/
}
public boolean removeCountry(String countryName) {
int result = this.sqliteDBInstance.delete(DB_TABLE_NAME,
"country_name='" + countryName + "'", null);
if (result > 0)
return true;
else
return false;
}
public long updateCountry(String oldCountryName, String newCountryName) {
ContentValues contentValues = new ContentValues();
contentValues.put(DB_COLUMN_1_NAME, newCountryName);
return this.sqliteDBInstance.update(DB_TABLE_NAME, contentValues,
"country_name='" + oldCountryName + "'", null);
}
public String[] getAllCountries() {
Cursor cursor = this.sqliteDBInstance.query(DB_TABLE_NAME,
new String[] { DB_COLUMN_1_NAME }, null, null, null, null,
DB_COLUMN_1_NAME + " ASC");
if (cursor.getCount() > 0) {
String[] str = new String[cursor.getCount()];
// String[] strpri = new String[cursor.getCount()];
int i = 0;
while (cursor.moveToNext()) {
str[i] = cursor.getString(cursor
.getColumnIndex(DB_COLUMN_1_NAME));
// strpri[i] = cursor.getString(cursor
// .getColumnIndex(DB_COLUMN_2_NAME));
i++;
}
return str;
} else {
return new String[] {};
}
}
}
I haven't figured out the crazy order but I found two things that might even clear something up:
your create table sql has one closing bracket too much (remove the one after the semicolon)
your insert method is really messy :) I would split it into two methods.
The general approach would be to create an insertOrUpdate method that queries the database for the entry (in your case the countryName). If an entry exist, it will be updated, if not it will be inserted. As you are a beginner, this might be a good task to do that by yourself, you should get the basic code here on SO in different questions.
The final tip (you might have seen it already): Use the parameter version and/or the real update/insert methods from the database.
db.insert(TABLE_NAME, null, contentValues); // see class ContentValues for details
According to the execSQL() method, you shouldn't use that for any SELECT/INSERT/UPDATE/DELETE statement:
Execute a single SQL statement that is NOT a SELECT/INSERT/UPDATE/DELETE.
Now my question which answer might help me to help you:
I would also like to know how you verified the order of your database content? Have you created a query in your android code where you query the content or have you opened the db file with a SQLite manager tool? If you query, can you include your query/display code in your question, too?
A couple of things to add to #WarrenFaith's excellent suggestions. I agree that the error is probably in code you haven't shown.
The quotes around the increment value in the UPDATE SQL are wrong. Should be e.g. quantity=quantity+42, not quantity=quantity+'42'
You need to use argument escapes (question marks ?) to avoid problems including SQL insertion attacks on your app.
The insert logic is insanely complicated. Perhaps this is where the problem lies.
You want something like:
// Insert or ignore.
ContentValues cv = new ContentValues();
cv.put("country_name", country_name);
cv.put("country_price", country_price);
sql.insertWithOnConflict(DB_TABLE_NAME, null, cv, CONFLICT_IGNORE);
// Increment the quantity field (there isn't a good way to do this with sql.update() )
sql.execSQL("UPDATE " + DB_TABLE_NAME + " SET country_quantity=country_quantity+? WHERE country_name=?",
new Object[] { new Long(country_quantity), country_name });
AND you didn't mention if the LogCat is clean. It must be showing DB errors at least regarding the quotes problem. Also suggest you make sure the table is dropped and rebuilt between debugging runs.
I have a table in my data base that has three columns: Screen, Icon, and Rank: and i am trying to find the cleanest way to achieve the following..
i want to find all rows WHERE Screen = "myScreen" and Rank >5 // then make rank one less than current value.. I am doing this in Java via a SQLite Manager class in the following function:
public void DeleteScreenIcon (int id, String screenName, int rank){
int screenID = getScreenID(screenName);
SQLiteDatabase db=this.getWritableDatabase();
db.delete(isLookUp, colScreenID + "=" + screenID + " and " +colIconID+ "="+id, null);
// HERE IS WHERE I NOW WANT TO DO THAT..
db.execSQL("update "+ isLookUp +" set "+colRank+ "=" +colRank+ " -1 "+" where " + colScreenID + "='" +screenName + "' and " + colRank +">" +rank);
db.close();
}
sorry, im not that versed in SQL any help is appreciated
This update should do the trick:
UPDATE myTable
SET Rank = Rank - 1
WHERE Screen = "myScreen"
AND Rank > 5;