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Database query android sqlite

I am stuck with one scenario in which I need to do complex query to get cursor. Don't know It is possible or not. Scenario is :
There are three tables in database.
Table Columns
Table-1 _id, name, number, ....
Table-2 _id, table1_id, col1, col2, ....
Table-3 _id, table2_id, col1, col2, ....
In these tables, when any record is inserted in table 2, corresponding table1 id is inserted in that record. Same for table2 id is inserted with table 3 record.
I want cursor for CursorAdapter to display list view of Table-3 data.
Cursor cursor = getContentResolver().query(TABLE_3_NAME, null, null, null, null);
Now need to add selection and selection args of Table-1 in this query.
Is it possible in Android?

You can use raw query to fetch from various tables. One example would be as below.
Cursor mCursor = db.rawQuery("SELECT * FROM Table-1, Table-3 " +
"WHERE Table1.id = <Whatever selection args you want> " +
"GROUP BY Table1.id", null);
This is just an example. You will have to change it as per your requirement.

You can write a SQL selection query (i.e. normal way) and you can execute using rawQuery() method.
For example:
Cursor cursor = db.rawQuery(selectQuery, null);

Why selection arguments only apply to the where clause in RawQuery?

Why selection arguments only apply to the where clause in RawQuery and not, for example in the from clause?
I'm asking this because in the "from clause" you might have the same things as in the "where clause", for example when using joins.
SELECT table1.field_x, table2.field_y FROM table1
LEFT OUTER JOIN table2 ON table1.field_x = table2.field_z AND table2.language =?
WHERE table1.language=?
I would like to make a Rawquery like this:
RawQuery("SELECT table1.field_x, table2.field_y FROM table1
LEFT OUTER JOIN table2 ON table1.field_x = table2.field_z AND table2.language =?
WHERE table1.language=?",
new String[] {language, language}
It doesn't give a semantic error, nor a compilation error, but it's not working at execution time.

Why selection arguments only apply to the where clause in RawQuery and not
Selection arguments do not apply to rawQuery, it applies to query.
Simplest method to create rawQuery with String array parameters, as to create new StringBuffer/StringBuilder object with parameters and appending strings in SB.
ForrawQuery("select DISTINCT tbl_name from sqlite_master where tbl_name = '" + tableName + "'", null)

SQLite query from multiple tables using SQLiteDatabase [duplicate]

This question already has answers here:
How do I join two SQLite tables in my Android application?
(4 answers)
Closed 8 years ago.
I have 2 tables in my database, for example: Table1: id (PK), data1 and Table2: id (PK), id_table1 (FK), data2. How can I make a query like that:
SELECT * FROM Table1, Table2 WHERE Table1.id = Table2.id_table1
GROUP BY Table1.data1
I'm using SQLiteDatabase and its query() method.
Cursor mCursor = db.query(true, new String[] {"Table1","Table2"},
new String[] {"Table1.id","data1", "Table2.id", "id_table1", "data2"},
"Table1.id=Table2.id_table1", null, "Table1.data1", null,null,null);
But there's a problem with the second arg - it's only possible to use String, not String[] (like new String[] {"Table1","Table2}). What should I do to make a query from multiple tables in that way?

Try this:
Cursor mCursor = db.rawQuery("SELECT * FROM Table1, Table2 " +
"WHERE Table1.id = Table2.id_table1 " +
"GROUP BY Table1.data1", null);

So when you need to JOIN Tables, you have to use rawQuery instead of query.
So your statement
String SELECT_QUERY = SELECT * FROM Table1 t1 INNER JOIN Table2 t2 ON t1.id = t2.id GROUP BY t1.data1;
I recommend to you use JOIN because it more faster and safer then your approach. So then your rawQuery method can looks like this:
cursor = db.rawQuery(SELECT_QUERY, null);
Have look at
rawQuery in SQLiteDatabase
Regards

Join in sqlite Android

I have two tables in my database table1, table2. I have a join query like this:
select a.*,b.* from table1 a,table2 b where a.field1=b.field1;
Its working fine while i test it in sqlite manager(sqlite browser). when i try to make it through java like this:
database.execSQL("select a.*,b.* from table1 a,table2 b where a.field1=b.field1;");
its saying return type is not cursor. How can i get it to cursor with join. I have to get that data and show in a listview

use like this:
String qry = "select a.*,b.* from table1 a,table2 b where a.field1=b.field1";
Cursor cur = db.rawQuery(qry,null);

String query = "select a.*,b.* from table1 a,table2 b where a.field1=b.field1;";
Cursor c = database.rawQuery(query, null);
/* do whatever you want with 'c' */

Following is an Example of rawQuery, you can add your Query Respectively.
String getRT = "SELECT count(*) from "+ DATABASE_PROFILE+";";
Cursor mCur = sqlitedb.rawQuery(getRT, null);
return mCur;

SQLiteDatabase.rawQuery(query, selectionArgs)
Use rawQuery method to design any sort of complex query you might need. In the reference there are many useful methods you might need.

SQLite rawquery

I am getting an error with a rawquery on Eclipse on a DB in the assets directory. The DB is 'pre-loaded' with tables and data and the SQL string, first comment line, works in SQLite DB browser. When I copy the SQL string to code and modify to remove quotes it errors. The code below is from the 'standard' public class DataBaseHelper extends SQLiteOpenHelper{ .I am new to android/java and would appreciate any assistance or suggestions.
public Cursor getAllSectionDescriptions( String DBtable, String source){
//Works in DB: SELECT "Description" FROM "SectionProps" WHERE Source = "UK"
//String q = "SELECT Description FROM SectionProps WHERE Source = UK " ; <= errors in code
String q = "SELECT Description FROM " + DBtable + " WHERE Source = " + source + " "; //<== errors in code
//06-24 16:53:03.373: ERROR/AndroidRuntime(1000): Caused by: android.database.sqlite.SQLiteException: no such table: SectionProps: , while compiling: SELECT Description FROM SectionProps WHERE Source = UK
Cursor mCursor = myDataBase.rawQuery(q, null);
mCursor.moveToFirst();
return mCursor;
}//end cursor

Looks like you have to put double quotes around your object names. So you'll want to do this:
String q = "SELECT \"Description\" FROM \"" + DBtable + "\" WHERE Source = \"" + source + "\" ";
Note the double quotes preceded by the escape character '\'

To execute queries, there are two methods: Execute db.rawQuery method Execute db.query method To execute a raw query to retrieve all departments:
Cursor getAllDepts()
{
SQLiteDatabase db=this.getReadableDatabase();
Cursor cur=db.rawQuery("SELECT "+colDeptID+" as _id,
"+colDeptName+" from "+deptTable,new String [] {});
return cur;
}
The rawQuery method has two parameters: String query: The select statement String[] selection args: The arguments if a WHERE clause is included in the select statement Notes The result of a query is returned in Cursor object. In a select statement if the primary key column (the id column) of the table has a name other than _id, then you have to use an alias in the form SELECT [Column Name] as _id cause the Cursor object always expects that the primary key column has the name _id or it will throw an exception .