问题
I am trying to search an item in sqlite by using String, & trying to return description contained in that row. items are stored in the table named Articles with column name A_name, Description column name is AS_name
This is my code, the cursor is not null, but the while loop is not getting executed once
public String searchData(String text)
{
Cursor cursor = sdb.query("Articles", new String[] {"A_name","AS_name"}, " A_name=?",new String[]{text}, null, null, null);
Log.e("running", "cursor run");
String temp = null,temp2 = null;
if(cursor!=null)
{
Log.e("running", "curosr is not null");
while(cursor.moveToFirst())
{
Log.e("running", "curosr while loop enter");
temp = (cursor.getString(cursor.getColumnIndex("A_name")));
//temp2 =(cursor.getString(cursor.getColumnIndex("AS_name")));
Log.e("running", "id email" +temp+ " name"+temp2);
}
}
return temp;
}
I want to return the corresponding element of AS_name, also I am confused what should I wrote in while loop ?
Can anyone please identify my mistake, Thanks in advance...
UPDATE DBAdapter.java
public class DBAdapter extends SQLiteOpenHelper
{
//CustomAdapter adapter;
static String name = "law6.sqlite";
static String path = "";
static ArrayList<GS> gs;
static SQLiteDatabase sdb;
@Override
public void onCreate(SQLiteDatabase db)
{
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion)
{
// TODO Auto-generated method stub
}
private DBAdapter(Context v)
{
super(v, name, null, 1);
path = "/data/data/" + v.getApplicationContext().getPackageName() + "/databases";
}
public boolean checkDatabase()
{
SQLiteDatabase db = null;
try
{
db = SQLiteDatabase.openDatabase(path + "/" + name, null, SQLiteDatabase.OPEN_READONLY);
} catch (Exception e)
{
e.printStackTrace();
}
if (db == null)
{
return false;
}
else
{
db.close();
return true;
}
}
public static synchronized DBAdapter getDBAdapter(Context v)
{
return (new DBAdapter(v));
}
public void createDatabase(Context v)
{
this.getReadableDatabase();
try
{
InputStream myInput = v.getAssets().open(name);
// Path to the just created empty db
String outFileName = path +"/"+ name;
// Open the empty db as the output stream
OutputStream myOutput = new FileOutputStream(outFileName);
// transfer bytes from the inputfile to the outputfile
byte[] buffer = new byte[1024];
int length;
while ((length = myInput.read(buffer)) > 0)
{
myOutput.write(buffer, 0, length);
}
// Close the streams
myOutput.flush();
myOutput.close();
myInput.close();
/*
InputStream is = v.getAssets().open("quiz.sqlite");
// System.out.println(is.available());
System.out.println(new File(path + "/" + name).getAbsolutePath());
FileOutputStream fos = new FileOutputStream(path + "/" + name);
int num = 0;
while ((num = is.read()) > 0) {
fos.write((byte) num);
}
fos.close();
is.close();*/
} catch (IOException e)
{
System.out.println(e);
}
}
public void openDatabase()
{
try
{
sdb = SQLiteDatabase.openDatabase(path + "/" + name, null,
SQLiteDatabase.OPEN_READWRITE);
} catch (Exception e)
{
System.out.println(e);
}
}
public ArrayList<GS> getData()
{
try{
Cursor c1 = sdb.rawQuery("SELECT DISTINCT * FROM Articles", null);
gs = new ArrayList<GS>();
while (c1.moveToNext())
{
GS q1 = new GS();
q1.setId(c1.getString(0));
q1.setA_id(c1.getString(1));
q1.setA_name(c1.getString(2));
q1.setAS_name(c1.getString(3));
q1.setDesc_art(c1.getString(4));
// q1.setAct(c1.getString(5));
q1.setExtra(c1.getString(6));
q1.setPart(c1.getString(7));
q1.setItalic(c1.getString(8));
Log.v("AS_name",q1.AS_name);
gs.add(q1);
}
}
catch (Exception e) {
e.printStackTrace();
}
return gs;
}
public String searchData(String text)
{
Cursor cursor = sdb.query("Articles", new String[] {"A_name","AS_name"}, " A_name=?",new String[]{text}, null, null, null);
Log.e("running", "cursor run");
String temp = null,temp2 = null;
if(cursor!=null)
{
Log.e("running", "curosr is not null");
Log.v("", ""+cursor.getCount());
while(cursor.moveToNext())
{
Log.e("running", "curosr while loop enter");
temp = (cursor.getString(cursor.getColumnIndex("AS_name")));
// temp2 =(cursor.getString(cursor.getColumnIndex(name)));
Log.e("running", "desc" +temp);
}
}
return temp;
}
}
UPDATE after implementing rajaji answer, I got this error :
回答1:
try this it will help you
create the raw query for getting the data
public String searchData(String text)
{
String strvalue=null;
SQliteDatabase db=this.getwritabledatabase();
Cursor cur=null;
String strquery="select * from youurtablename where A_name="+text;
cur=db.rawQuery(strquery,null);
if(cur!=null&&cur.moveToFirst())
{
do
{
strvalue=cur.getString(0);
}
while(cur.moveToNext());
}
}
let me inform once you complete
回答2:
Is your Uri correct??
create Uri depends on your package name and table name, like the code below :
private static final String AUTHORITY = "com.sample.test_db_provider";
private static final String BASE_PATH = "Tables";
private static final Uri Sample_URI = Uri.parse("content://" + AUTHORITY
+ "/" + BASE_PATH
+ "/SampleTable");
Then in your get Method, query the db like the below code with Uri
cur = m_Resolver.query(Sample_URI, new String[] {"A_name","AS_name"},
"SampleTable.A_name = " + text, null, null);
if(cur != null && cur.moveToFirst())
{
do
{
...
}
while(cur.moveToNext());
}
cur.close();
I use the inline where clause but you can do it your way with a parameter. Is this what you are looking for?
来源：https://stackoverflow.com/questions/24584122/getting-a-unique-row-in-sqlite