I have a database table with multiple columns
I use custom List<> and populate it from database
What i want to do is filter what will go into the list from database depending on user input
for example if i had a table like this:
name|phone|date|address
User can specify any filter(by name, by phone, by date... or all of it) and only items that matches all criteria will go into the list
Is there a way to do this?
Method that returns all items from database
public List<MoviesDatabaseEntry> getAllMovies(String table)
{
List<MoviesDatabaseEntry> lists = new ArrayList<MoviesDatabaseEntry>();
// Select All Query
String selectQuery = "SELECT * FROM " + table;
SQLiteDatabase db = this.getWritableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
// looping through all rows and adding to list
if (cursor.moveToFirst())
{
do {
MoviesDatabaseEntry list = new MoviesDatabaseEntry();
list.set_id(Integer.parseInt(cursor.getString(0)));
list.set_title(cursor.getString(1));
list.set_runtime(cursor.getString(2));
list.set_rating(cursor.getDouble(3));
list.set_genres(cursor.getString(4));
list.set_type(cursor.getString(5));
list.set_lang(cursor.getString(6));
list.set_poster(cursor.getString(7));
list.set_url(cursor.getString(8));
list.set_director(cursor.getString(9));
list.set_actors(cursor.getString(10));
list.set_plot(cursor.getString(11));
list.set_year(cursor.getInt(12));
list.set_country(cursor.getString(13));
list.set_date(cursor.getInt(14));
// Adding to list
lists.add(list);
} while (cursor.moveToNext());
}
// return list
db.close();
cursor.close();
return lists;
}
You can filter the entries you get in the SQL query you are building in this line:
String selectQuery = "SELECT * FROM " + table;
To filter the dataset your retrieve, you would add a WHERE clause to it. When you would, for example, only want those entries where the rating is over 3, you would change this to:
String selectQuery = "SELECT * FROM " + table + " WHERE rating > 3";
SQL is a very powerful language which offers a lot of possibilities. It's an essential skill when you work with relational databases. When you want to learn it, I can recommend you the interactive tutorial website http://sqlzoo.net/
You have to change your database query for getting specific data from the query.
You have one function that returns all rows from database like so: getAllMovies(String table)
Here you are using:
String selectQuery = "SELECT * FROM " + table;
Make a new function like this:
public List<MoviesDatabaseEntry> getSelectedMovies(String table)
{
List<MoviesDatabaseEntry> lists = new ArrayList<MoviesDatabaseEntry>();
Cursor cursor = db.query(true, TABLE_NAME, new String[] { <your row names> },
**check condition(as string)**, null,
null, null, null, null);
...
}
Now just call this function when required with your specific query string
Make as many functions as you want!
Related
I have an Android app with a SQL database that has 4 columns. I would like to search all 4 columns in the database however I can only get 1 to be searched.
I'm not quite sure on how to get it to search all 4 columns.
All 4 Columns are displayed but I can only search one. I can not seem to get it to search all 4 columns.
the code I'm using to get it to search one column is
#SuppressLint("Range")
public List<Data> getDataByVARIETY (String VARIETY) {
variety = VARIETY;
SQLiteDatabase db = getReadableDatabase();
SQLiteQueryBuilder qb = new SQLiteQueryBuilder();
String[] sqlSelect = {"VARIETY", "COMMODITY", "PLU", "BOTANICAL"};
String tableName = "data";
qb.setTables(tableName);
//This will query : Select * from Data where Variety %PATTERN%"
Cursor cursor = qb.query(db, sqlSelect, "VARIETY LIKE ?", new String[]{"%" + VARIETY + "%"}, null, null, null);
List<Data> result = new ArrayList<>();
if (cursor.moveToFirst()) {
do {
Data data = new Data();
data.setCOMMODITY(cursor.getString(cursor.getColumnIndex("COMMODITY")));
data.setVARIETY(cursor.getString(cursor.getColumnIndex("VARIETY")));
data.setPLU(cursor.getString(cursor.getColumnIndex("PLU")));
data.setBOTANICAL(cursor.getString(cursor.getColumnIndex("BOTANICAL")));
result.add(data);
} while (cursor.moveToNext());
}
return result;
}
so all i had to do was
change this
qb.setTables(tableName);
//This will query : Select * from Data where Variety %PATTERN%"
Cursor cursor = qb.query(db, sqlSelect, "VARIETY LIKE ?", new String[]{"%" + VARIETY + "%"}, null, null, null);
to this
qb.setTables(tableName);
//This will query : Select * from Data where Variety %PATTERN%"
String conditions = "COMMODITY LIKE ? OR PLU LIKE ? OR VARIETY LIKE ?";
String par;
par = "%"+COMMODITY+"%";
Cursor cursor = db.query(tableName, sqlSelect, conditions, new String[]{par, par, par}, null, null, null);
so i recently learn to write a code in android using sqlite and i try to select data from sqlite but this error occur
ive tried some suggestion from the internet and read my book but i didnt solve my problem
public Penyakit getPenyakit1(String namaGejal){
SQLiteDatabase db = this.getReadableDatabase();
String query = "SELECT idPen FROM " + TABLE_CONTACTS + " WHERE " +
namapen + " =\"" + namaGejal + "\"";
Cursor cursor = db.rawQuery(query,null);
Penyakit penyakit = new Penyakit();
if(cursor.moveToFirst()){
cursor.moveToFirst();
penyakit.set_nomber(Integer.parseInt(cursor.getColumnName(0)));
penyakit.set_namaPen(cursor.getColumnName(1));
penyakit.set_idPenyakit(Integer.parseInt(cursor.getColumnName(2)));
penyakit.set_namGej(cursor.getColumnName(3));
penyakit.set_idGejala(Integer.parseInt(cursor.getColumnName(4)));
cursor.close();
} else {
penyakit=null;
}
return penyakit;
}
this is logcat
Process: com.example.lordbramasta.pakar, PID: 18914
java.lang.NumberFormatException: For input string: "idPen"
at java.lang.Integer.parseInt(Integer.java:615)
at java.lang.Integer.parseInt(Integer.java:650)
at com.example.lordbramasta.pakar.DBAdapter.getPenyakit1(DBAdapter.java:79)
i expected the value of idPen get selected , thank you
Your problem is this line:
penyakit.set_nomber(Integer.parseInt(cursor.getColumnName(0)));
cursor.getColumnName(0) returns idPen as this is the name of the only column returned by your query:
SELECT idPen FROM ....
and your code is trying to cast the string "idPen" to an integer.
So getColumnName() returns the name of the column at a specified index and not the value of the column.
You should do
penyakit.set_nomber(Integer.parseInt(cursor.getString(0)));
or if the data type of the column idPen is INTEGER then:
penyakit.set_nomber(cursor.getInt(0));
Also don't try to get any other columns because your query returns only 1.
Note: remove that cursor.moveToFirst(); inside the if block because it is already executed.
Probably you need to use a ' instead of ". So, change the query to the following:
String query = "SELECT idPen FROM " + TABLE_CONTACTS + " WHERE " +
namapen + " =\'" + namaGejal + "\'";
I'm suggesting you to use SQLiteDatabase.query() instead rawQuery like this:
// Define a projection that specifies which columns from the database
// you will actually use after this query.
String[] projection = {
"idPen"
};
// Filter results WHERE "namapen" = 'namaGejal'
String selection = "namapen" + " = ?";
String[] selectionArgs = { namaGejal };
// How you want the results sorted in the resulting Cursor
String sortOrder = null; // null for default order
Cursor cursor = db.query(
TABLE_CONTACTS, // The table to query
projection, // The array of columns to return (pass null to get all)
selection, // The columns for the WHERE clause
selectionArgs, // The values for the WHERE clause
null, // don't group the rows
null, // don't filter by row groups
sortOrder // The sort order
);
// do something with the cursor
Please take a look Read information from a database
If you want to get all columns data from your TABLE_CONTACTS use SELECT * FROM
I have table contains columns id, name, profession, age, hobby, country, sex. Now I want to update the fields where sex is female and age is 30. All the fields are text (String). First, I am counting all the rows then running a loop to update the rows. Loop is running as per the total rows but rows are not updated... WHY? Where I have done the mistake? Here is my code:
METHODS FOR ANDROID SQLITE DATABASE QUERY:
public void updateUser(String newProfession, String newCountry, String sx, String ag) {
SQLiteDatabase db = this.getWritableDatabase();
String query = "UPDATE "+TABLE_USER+" SET "+KEY_PROFESSION+"='"+newProfession+"', "+KEY_COUNTRY+"='"+newCountry+"' WHERE "+KEY_SEX+"='"+sx+"' AND "+KEY_AGE+"='"+ag+"'";
Cursor cursor = db.rawQuery(query, null);
cursor.close();
db.close();
}
public int countAll() {
String countQuery = "SELECT * FROM " + TABLE_USER;
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery(countQuery, null);
int cnt = cursor.getCount();
cursor.close();
db.close();
return cnt;
}
CALLING THE METHODS
public void updateUsersClicked(View view) {
int allData = db.countAll();
for (int i = 0; i < allData; i++) {
db.updateUser("SENIOR ENGINEER", "CANADA", "female", "30");
System.out.println("T H I S I S T H E R E S U L T: " + i);
}
}
Use execSQL() and not rawQuery() for updates.
rawQuery() just compiles the SQL and requires one of the moveTo...() methods on the returned Cursor to execute it. execSQL() both compiles and runs the SQL.
Also consider using ? parameters with bind args in your SQL to avoid escaping special characters and being vulnerable to SQL injection.
You don't need to do the for loop
a single QSL "Update" query is enough if you want to update All the female with age 30.
If you are new to SQL you can view a simple example here:
Simple SQL Update example
If you want to do something else - please edit your question
In my Android database, I have number of tables. Among these tables, some contain similar names starting from "List_". For an example, there are tables like "List_A", "List_B", "List_C" etc. How can I get the list of all tables which starts from the word "List_" using code?
This should do the trick :)
SELECT *
FROM dbname.sqlite_master
WHERE type='table'
AND name LIKE 'List_%'
try this way
public void grabTables() {
Cursor cur = this.db.rawQuery("SELECT * FROM sqlite_master where name like 'List_%'", new String[0]);
cur.moveToFirst();
String tableName;
while (cur.getPosition() < cur.getCount()) {
tableName = cur.getString(cur.getColumnIndex("name"));
System.out.println("Table Name = " + tableName);
cur.moveToNext();
}
cur.close();
}
I have tried this code
Cursor c=db.rawQuery("SELECT name FROM sqlite_master WHERE type = 'table'",null);
c.moveToFirst();
while(!c.isAfterLast()){
Toast.makeText(activityName.this, "Table Name=> "+c.getString(0),
Toast.LENGTH_LONG).show();
}
But it throws the error:
"android.database.sqlite.SQLiteException: no such table: sqlite_master(code 1):, while
compiling: SELECT name FROM sqlite_master WHERE type='table'"
How to fetch all the table names?
Checked, tested and functioning. Try this code:
Cursor c = db.rawQuery("SELECT name FROM sqlite_master WHERE type='table'", null);
if (c.moveToFirst()) {
while ( !c.isAfterLast() ) {
Toast.makeText(activityName.this, "Table Name=> "+c.getString(0), Toast.LENGTH_LONG).show();
c.moveToNext();
}
}
I am assuming, at some point down the line, you will to grab a list of the table names to display in perhaps a ListView or something. Not just show a Toast.
Untested code. Just what came at the top of my mind. Do test before using it in a production app. ;-)
In that event, consider the following changes to the code posted above:
ArrayList<String> arrTblNames = new ArrayList<String>();
Cursor c = db.rawQuery("SELECT name FROM sqlite_master WHERE type='table'", null);
if (c.moveToFirst()) {
while ( !c.isAfterLast() ) {
arrTblNames.add( c.getString( c.getColumnIndex("name")) );
c.moveToNext();
}
}
Change your sql string to this one:
"SELECT name FROM sqlite_master WHERE type='table' AND name!='android_metadata' order by name"
To get table name with list of all column of that table
public void getDatabaseStructure(SQLiteDatabase db) {
Cursor c = db.rawQuery(
"SELECT name FROM sqlite_master WHERE type='table'", null);
ArrayList<String[]> result = new ArrayList<String[]>();
int i = 0;
result.add(c.getColumnNames());
for (c.moveToFirst(); !c.isAfterLast(); c.moveToNext()) {
String[] temp = new String[c.getColumnCount()];
for (i = 0; i < temp.length; i++) {
temp[i] = c.getString(i);
System.out.println("TABLE - "+temp[i]);
Cursor c1 = db.rawQuery(
"SELECT * FROM "+temp[i], null);
c1.moveToFirst();
String[] COLUMNS = c1.getColumnNames();
for(int j=0;j<COLUMNS.length;j++){
c1.move(j);
System.out.println(" COLUMN - "+COLUMNS[j]);
}
}
result.add(temp);
}
}
Try adding the schema before the table
schema.sqlite_master
From SQL FAQ
If you are running the sqlite3 command-line access program you can type ".tables" to get a list of all tables. Or you can type ".schema" to see the complete database schema including all tables and indices. Either of these commands can be followed by a LIKE pattern that will restrict the tables that are displayed.
From within a C/C++ program (or a script using Tcl/Ruby/Perl/Python bindings) you can get access to table and index names by doing a SELECT on a special table named "SQLITE_MASTER". Every SQLite database has an SQLITE_MASTER table that defines the schema for the database. The SQLITE_MASTER table looks like this:
CREATE TABLE sqlite_master (
type TEXT,
name TEXT,
tbl_name TEXT,
rootpage INTEGER,
sql TEXT
);
Try this:
SELECT name FROM sqlite_master WHERE type = "table";
I tested Siddharth Lele answer with Kotlin and Room, and it works as well.
The same code but using Kotlin and Room is something like that:
val cursor = roomDatabaseInstance.query(SimpleSQLiteQuery("SELECT name FROM sqlite_master WHERE type='table' AND name NOT IN ('android_metadata', 'sqlite_sequence', 'room_master_table')"))
val tableNames = arrayListOf<String>()
if(cursor.moveToFirst()) {
while (!cursor.isAfterLast) {
tableNames.add(cursor.getString(0))
cursor.moveToNext()
}
}