Android中的SQLite如何更新特定行

我一直在尝试更新特定行已有一段时间了，看来有两种方法可以做到这一点。根据我的阅读和尝试，您可以使用：

execSQL(String sql) 方法

或者：

update(String table, ContentValues values, String whereClause, String[] whereArgs) 方法。

（让我知道这是否不正确，因为我是android新手，还是SQL新手。）

因此，让我了解我的实际代码。

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

我正在努力做到这一点：

更新Field1，Field2和Field3，其中主键（_id）等于1。

Eclipse在“更新”一词的正下方给出了一条红线，并给出了以下解释：

SQLiteDatabase类型的方法update（String，ContentValues，String，String []）不适用于参数（String，String，String，null）

我猜我没有正确分配ContentValues。谁能指出我正确的方向？

首先创建一个ContentValues对象：

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");

然后使用更新方法，它现在应该可以工作：

myDB.update(TableName, cv, "_id="+id, null);

简单方法：

String strSQL = "UPDATE myTable SET Column1 = someValue WHERE columnId = "+ someValue;

myDataBase.execSQL(strSQL);

首先创建一个ContentValues对象：

ContentValues cv = new ContentValues();
cv.put("Field1","Bob");
cv.put("Field2","19");

然后使用更新方法。注意，第三个参数是where子句。“？” 是一个占位符。它将被第四个参数（id）取代

myDB.update(MY_TABLE_NAME, cv, "_id = ?", new String[]{id});

这是更新特定行的最干净的解决方案。

1. 我个人更喜欢.update的方便。但是execsql将起作用。
2. 您的猜测正确，您的问题在于您的内容价值。您应该创建一个ContentValue对象，然后将数据库行的值放在其中。

此代码应修复您的示例：

 ContentValues data=new ContentValues();
 data.put("Field1","bob");
 data.put("Field2",19);
 data.put("Field3","male");
 DB.update(Tablename, data, "_id=" + id, null);

你可以试试这个...

db.execSQL("UPDATE DB_TABLE SET YOUR_COLUMN='newValue' WHERE id=6 ");

希望这对您有帮助：

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

您可以在SQLite中尝试这种更新方法

int id;
ContentValues con = new ContentValues();
con.put(TITLE, title);
con.put(AREA, area);
con.put(DESCR, desc);
con.put(TAG, tag);
myDataBase.update(TABLE, con, KEY_ID + "=" + id,null);

在您的数据库`中使用此代码

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;
     }

用于在您的sample.java中进行更新，请使用此代码

  //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();

可以这样尝试：

ContentValues values=new ContentValues();
values.put("name","aaa");
values.put("publisher","ppp");
values.put("price","111");

int id=sqdb.update("table_name",values,"bookid='5' and booktype='comic'",null);

如果您的sqlite行具有唯一ID或其他等效项，则可以使用where子句，例如

update .... where id = {here is your unique row id}

对于更新，需要调用setTransactionSuccessfull来使更改提交，如下所示：

db.beginTransaction();
try {
    db.update(...) 
    db.setTransactionSuccessfull(); // changes get rolled back if this not called
} finally {
   db.endTransaction(); // commit or rollback
}

//这里有一些简单的示例代码可用于更新

//首先声明这个

private DatabaseAppHelper dbhelper;
private SQLiteDatabase db;

//初始化以下内容

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

//更新代码

 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);

//在我的共享首选项中，输入您的id而不是“问号”是一个函数。

 public void updateRecord(ContactModel contact) {
    database = this.getReadableDatabase();
    ContentValues contentValues = new ContentValues();
    contentValues.put(COLUMN_FIRST_NAME, contact.getFirstName());
    contentValues.put(COLUMN_LAST_NAME, contact.getLastName());
    contentValues.put(COLUMN_NUMBER,contact.getNumber());
    contentValues.put(COLUMN_BALANCE,contact.getBalance());
    database.update(TABLE_NAME, contentValues, COLUMN_ID + " = ?", new String[]{contact.getID()});
    database.close();
}

只是尝试这种方式

  String strFilter = "_id=" + Id;
  ContentValues args = new ContentValues();
  args.put(KEY_TITLE, title);
  myDB.update("titles", args, strFilter, null);**

SQLite中的更新方法：

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);
}

SQLiteDatabase myDB = this.getWritableDatabase();

ContentValues cv = new ContentValues();
cv.put(key1,value1);    
cv.put(key2,value2); /*All values are your updated values, here you are 
                       putting these values in a ContentValues object */
..................
..................

int val=myDB.update(TableName, cv, key_name +"=?", new String[]{value});

if(val>0)
 //Successfully Updated
else
 //Updation failed

public long fillDataTempo(String table){
    String[] table = new String[1];
    tabela[0] = table; 
    ContentValues args = new ContentValues();
    args.put(DBOpenHelper.DATA_HORA, new Date().toString());
    args.put(DBOpenHelper.NOME_TABELA, nome_tabela);
    return db.update(DATABASE_TABLE, args, STRING + " LIKE ?" ,tabela);
}

只需提供rowId和将在ContentValues中更新的数据类型。

公共无效updateStatus（字符串id，int状态）{

SQLiteDatabase db = this.getWritableDatabase（）;

ContentValues数据= new ContentValues（）;

data.put（“ status”，status）;

db.update（TableName，data，“ columnName” +“ =” + id，null）;

}

我将通过一个完整的例子进行演示

这样创建数据库

    import android.content.Context
    import android.database.sqlite.SQLiteDatabase
    import android.database.sqlite.SQLiteOpenHelper

    class DBHelper(context: Context) : SQLiteOpenHelper(context, DATABASE_NAME, null, DATABASE_VERSION) {
        override fun onCreate(db: SQLiteDatabase) {
            val createProductsTable = ("CREATE TABLE " + Business.TABLE + "("
                    + Business.idKey + " INTEGER PRIMARY KEY AUTOINCREMENT ,"
                    + Business.KEY_a + " TEXT, "
                    + Business.KEY_b + " TEXT, "
                    + Business.KEY_c + " TEXT, "
                    + Business.KEY_d + " TEXT, "
                    + Business.KEY_e + " TEXT )")
            db.execSQL(createProductsTable)
        }
        override fun onUpgrade(db: SQLiteDatabase, oldVersion: Int, newVersion: Int) {
            // Drop older table if existed, all data will be gone!!!
            db.execSQL("DROP TABLE IF EXISTS " + Business.TABLE)
            // Create tables again
            onCreate(db)

        }
        companion object {
            //version number to upgrade database version
            //each time if you Add, Edit table, you need to change the
            //version number.
            private val DATABASE_VERSION = 1

            // Database Name
            private val DATABASE_NAME = "business.db"
        }
    }

然后创建一个促进CRUD的类-> Create | Read | Update | Delete

class Business {
    var a: String? = null
    var b: String? = null
    var c: String? = null
    var d: String? = null
    var e: String? = null

    companion object {
        // Labels table name
        const val TABLE = "Business"
        // Labels Table Columns names
        const val rowIdKey = "_id"
        const val idKey = "id"
        const val KEY_a = "a"
        const val KEY_b = "b"
        const val KEY_c = "c"
        const val KEY_d = "d"
        const val KEY_e = "e"
    }
}

魔法来了

import android.content.ContentValues
import android.content.Context

    class SQLiteDatabaseCrud(context: Context) {
        private val dbHelper: DBHelper = DBHelper(context)

        fun updateCart(id: Int, mBusiness: Business) {
            val db = dbHelper.writableDatabase
            val valueToChange = mBusiness.e
            val values = ContentValues().apply {
                put(Business.KEY_e, valueToChange)
            }
            db.update(Business.TABLE, values, "id=$id", null)
            db.close() // Closing database connection
        }
    }

您必须创建必须返回CursorAdapter的ProductsAdapter

所以在一个活动中只需调用这样的函数

internal var cursor: Cursor? = null
internal lateinit var mProductsAdapter: ProductsAdapter

 mSQLiteDatabaseCrud = SQLiteDatabaseCrud(this)
    try {
        val mBusiness = Business()
        mProductsAdapter = ProductsAdapter(this, c = todoCursor, flags = 0)
        lstProducts.adapter = mProductsAdapter


        lstProducts.onItemClickListener = OnItemClickListener { parent, view, position, arg3 ->
                val cur = mProductsAdapter.getItem(position) as Cursor
                cur.moveToPosition(position)
                val id = cur.getInt(cur.getColumnIndexOrThrow(Business.idKey))

                mBusiness.e = "this will replace the 0 in a specific position"
                mSQLiteDatabaseCrud?.updateCart(id ,mBusiness)

            }

        cursor = dataBaseMCRUD!!.productsList
        mProductsAdapter.swapCursor(cursor)
    } catch (e: Exception) {
        Log.d("ExceptionAdapter :",""+e)
    }