SQLite in Android How to update a specific row

2019-01-02 14:57发布

I've been trying to update a specific row for a while now, and it seems that there are two ways to do this. From what I've read and tried, you can just use the:

execSQL(String sql) method

or the:

update(String table, ContentValues values, String whereClause, String[] whereArgs) method.

(Let me know if this is incorrect as I am new to android and very new to SQL.)

So let me get to my actual code.

myDB.update(TableName, "(Field1, Field2, Field3)" + " VALUES ('Bob', 19, 'Male')", "where _id = 1", null);

I am trying to accomplish this:

Update Field1, Field2, and Field3 where the primary key (_id) is equal to 1.

Eclipse gives me a red line right underneath the word "update" and gives me this explanation:

The method update(String, ContentValues, String, String[]) in the type SQLiteDatabase is not applicable for the arguments (String, String, String, null)

I'm guessing I'm not assigning the ContentValues correctly. Can anyone point me in the right direction?

16条回答
零度萤火
2楼-- · 2019-01-02 15:26

First make a ContentValues object :

ContentValues cv = new ContentValues();
cv.put("Field1","Bob"); //These Fields should be your String values of actual column names
cv.put("Field2","19");
cv.put("Field2","Male");

Then use the update method, it should work now:

myDB.update(TableName, cv, "_id="+id, null);
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不流泪的眼
3楼-- · 2019-01-02 15:26

you can try this...

db.execSQL("UPDATE DB_TABLE SET YOUR_COLUMN='newValue' WHERE id=6 ");
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十年一品温如言
4楼-- · 2019-01-02 15:29

//Here is some simple sample code for update

//First declare this

private DatabaseAppHelper dbhelper;
private SQLiteDatabase db;

//initialize the following

dbhelper=new DatabaseAppHelper(this);
        db=dbhelper.getWritableDatabase();

//updation code

 ContentValues values= new ContentValues();
                values.put(DatabaseAppHelper.KEY_PEDNAME, ped_name);
                values.put(DatabaseAppHelper.KEY_PEDPHONE, ped_phone);
                values.put(DatabaseAppHelper.KEY_PEDLOCATION, ped_location);
                values.put(DatabaseAppHelper.KEY_PEDEMAIL, ped_emailid);
                db.update(DatabaseAppHelper.TABLE_NAME, values,  DatabaseAppHelper.KEY_ID + "=" + ?, null);

//put ur id instead of the 'question mark' is a function in my shared preference.

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余生无你
5楼-- · 2019-01-02 15:30
  1. I personally prefere .update for its convenience. But execsql will work same.
  2. You are right with your guess that the problem is your content values. You should create a ContentValue Object and put the values for your database row there.

This code should fix your example:

 ContentValues data=new ContentValues();
 data.put("Field1","bob");
 data.put("Field2",19);
 data.put("Field3","male");
 DB.update(Tablename, data, "_id=" + id, null);
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美炸的是我
6楼-- · 2019-01-02 15:33

use this code in your DB `

public boolean updatedetails(long rowId,String name, String address)
      {
       ContentValues args = new ContentValues();
       args.put(KEY_ROWID, rowId);          
       args.put(KEY_NAME, name);
       args.put(KEY_ADDRESS, address);
       int i =  mDb.update(DATABASE_TABLE, args, KEY_ROWID + "=" + rowId, null);
    return i > 0;
     }

for updating in your sample.java use this code

  //DB.open();

        try{
              //capture the data from UI
              String name = ((EditText)findViewById(R.id.name)).getText().toString().trim();
              String address =(EditText)findViewById(R.id.address)).getText().toString().trim();

              //open Db
              pdb.open();

              //Save into DBS
              pdb.updatedetails(RowId, name, address);
              Toast.makeText(this, "Modified Successfully", Toast.LENGTH_SHORT).show();
              pdb.close();
              startActivity(new Intent(this, sample.class));
              finish();
        }catch (Exception e) {
            Log.e(TAG_AVV, "errorrrrr !!");
            e.printStackTrace();
        }
    pdb.close();
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皆成旧梦
7楼-- · 2019-01-02 15:34

Method for updation in SQLite:

public void updateMethod(String name, String updatename){
    String query="update students set email = ? where name = ?";
    String[] selections={updatename, name};
    Cursor cursor=db.rawQuery(query, selections);
}
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