我正在尝试在android数据库中添加数据然后尝试从列表中检索数据但是我收到错误。我为MainActivity创建了三个java文件，一个用于数据库连接，另一个用于信息
这是MainActivity.java
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
DatabaseHandler db=new DatabaseHandler(this);
/*inserting dat*/
Log.d("Insert", "Element inserting");
db.addcontacts(new Contact("Ravi", "9100000000"));
db.addcontacts(new Contact("Srinivas", "9199999999"));
db.addcontacts(new Contact("Tommy", "9522222222"));
db.addcontacts(new Contact("Karthik", "9533333333"));
// Reading all contacts
Log.d("Reading: ", "Reading all contacts..");
ArrayList<Contact> contacts = db.getallcontact();
for (Contact cn : contacts) {
String log = "Id: "+cn.getId()+" ,Name: " + cn.getName() + " ,Phone: " +
cn.getPhonenumber();
// Writing Contacts to log
Log.d("Name: ", log);
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
这是Contact.java
public class Contact {
private int _ID;
private String _name;
private String _phone_number;
public Contact(){
}
public Contact(int id,String Name, String Phone_Number){
_ID=id;
_name=Name;
_phone_number=Phone_Number;
}
public Contact(String Phone_Number,String Name){
_name=Name;
_phone_number=Phone_Number;
}
public int getId(){
return _ID;
}
public String getName(){
return _name;
}
public String getPhonenumber(){
return _phone_number;
}
public void setName(String name){
_name=name;
}
public void setPhonenumber(String phone){
_phone_number=phone;
}
public void setId(int id) {
// TODO Auto-generated method stub
_ID=id;
}
}
这是databasehandler.java
public class DatabaseHandler extends SQLiteOpenHelper {
private static int version=1;
private static final String DATABASE_NAME="contactManager";
private static String KEY_ID="id";
private static String KEY_NAME="name";
private static String KEY_PH_NO="phone_number";
private static String TABLE_CONTACTS="contacts";
public DatabaseHandler(Context context) {
super(context, DATABASE_NAME, null, version);
// TODO Auto-generated constructor stub
}
@Override
public void onCreate(SQLiteDatabase arg0) {
// TODO Auto-generated method stub
String TABLE_CREATE="create"+TABLE_CONTACTS+"("+KEY_ID+"integer primary key
autoincrement,"+
KEY_NAME+"text,"+KEY_PH_NO+"text;)";
arg0.execSQL(TABLE_CREATE);
}
@Override
public void onUpgrade(SQLiteDatabase arg0, int arg1, int arg2) {
// TODO Auto-generated method stub
arg0.execSQL("drop TABLE IF EXITS"+TABLE_CONTACTS);
onCreate(arg0);
}
public void addcontacts(Contact contact){
SQLiteDatabase db=this.getWritableDatabase();
ContentValues values=new ContentValues();
values.put(KEY_NAME, contact.getName());
values.put(KEY_PH_NO, contact.getPhonenumber());
db.insert(TABLE_CONTACTS, null, values);
db.close();
}
public Contact getcontact(int id){
SQLiteDatabase db=this.getReadableDatabase();
Cursor cursor=db.query(TABLE_CONTACTS,new String[]{KEY_ID,
KEY_NAME,KEY_PH_NO},KEY_ID+"?", new String[] { String.valueOf(id) },
null,null, null);
if(cursor!=null){
cursor.moveToFirst();
}
Contact contact=new
Contact(Integer.parseInt(cursor.getString(0)),cursor.getString(1),cursor.getString(2));
return contact;
}
public ArrayList<Contact> getallcontact(){
ArrayList<Contact> contactlist=new ArrayList<Contact>();
SQLiteDatabase db=this.getReadableDatabase();
String selectQuery = "SELECT * FROM " + TABLE_CONTACTS;
Cursor cursor=db.rawQuery(selectQuery, null);
if(cursor.moveToFirst())
{
do{
Contact contact=new Contact();
contact.setId(Integer.parseInt (cursor.getString(0)));
contact.setName(cursor.getString(1));
contact.setPhonenumber(cursor.getString(2));
contactlist.add(contact);
}while(cursor.moveToNext());
}
return contactlist;
}
}
这里是logcat
06-29 07:38:51.640: D/Insert(1057): Element inserting
06-29 07:38:52.000: E/SQLiteLog(1057): (1) near "createcontacts": syntax error
06-29 07:38:52.010: D/AndroidRuntime(1057): Shutting down VM
06-29 07:38:52.010: W/dalvikvm(1057): threadid=1: thread exiting with uncaught
exception (group=0xb4a6bb90)
06-29 07:38:52.080: E/AndroidRuntime(1057): FATAL EXCEPTION: main
06-29 07:38:52.080: E/AndroidRuntime(1057): Process: com.example.datbase, PID: 1057
06-29 07:38:52.080: E/AndroidRuntime(1057): java.lang.RuntimeException: Unable to start
activity ComponentInfo{com.example.datbase/com.example.datbase.MainActivity}:
android.database.sqlite.SQLiteException: near "createcontacts": syntax error (code 1):
, while compiling: createcontacts(idinteger primary key
autoincrement,nametext,phone_numbertext;)
06-29 07:38:52.080: E/AndroidRuntime(1057): at
android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2176)
06-29 07:38:52.080: E/AndroidRuntime(1057): at
android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2226)
06-29 07:38:52.080: E/AndroidRuntime(1057): at
android.app.ActivityThread.access$700(ActivityThread.java:135)
06-29 07:38:52.080: E/AndroidRuntime(1057): at
android.app.ActivityThread$H.handleMessage(ActivityThread.java:1397)
06-29 07:38:52.080: E/AndroidRuntime(1057): at
android.os.Handler.dispatchMessage(Handler.java:102)
06-29 07:38:52.080: E/AndroidRuntime(1057): at
android.os.Looper.loop(Looper.java:137)
06-29 07:38:52.080: E/AndroidRuntime(1057): at
android.app.ActivityThread.main(ActivityThread.java:4998)
06-29 07:38:52.080: E/AndroidRuntime(1057): at
java.lang.reflect.Method.invokeNative(Native Method)
06-29 07:38:52.080: E/AndroidRuntime(1057): at
java.lang.reflect.Method.invoke(Method.java:515)
06-29 07:38:52.080: E/AndroidRuntime(1057): at
com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:777)
06-29 07:38:52.080: E/AndroidRuntime(1057): at
com.android.internal.os.ZygoteInit.main(ZygoteInit.java:593)
06-29 07:38:52.080: E/AndroidRuntime(1057): at
dalvik.system.NativeStart.main(Native Method)
06-29 07:38:52.080: E/AndroidRuntime(1057): Caused by:
android.database.sqlite.SQLiteException: near "createcontacts": syntax error (code 1):
, while compiling: createcontacts(idinteger primary key
autoincrement,nametext,phone_numbertext;)
06-29 07:38:52.080: E/AndroidRuntime(1057): at
android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method)
06-29 07:38:52.080: E/AndroidRuntime(1057): at
android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:889)
06-29 07:38:52.080: E/AndroidRuntime(1057): at
android.database.sqlite.SQLiteConnection.prepare(SQLiteConnection.java:500)
06-29 07:38:52.080: E/AndroidRuntime(1057): at
android.database.sqlite.SQLiteSession.prepare(SQLiteSession.java:588)
06-29 07:38:52.080: E/AndroidRuntime(1057): at android.database.sqlite.SQLiteProgram.
<init>(SQLiteProgram.java:58)
06-29 07:38:52.080: E/AndroidRuntime(1057): at android.database.sqlite.SQLiteStatement.
<init>(SQLiteStatement.java:31)
06-29 07:38:52.080: E/AndroidRuntime(1057): at
android.database.sqlite.SQLiteDatabase.executeSql(SQLiteDatabase.java:1672)
06-29 07:38:52.080: E/AndroidRuntime(1057): at
android.database.sqlite.SQLiteDatabase.execSQL(SQLiteDatabase.java:1603)
06-29 07:38:52.080: E/AndroidRuntime(1057): at
com.example.datbase.DatabaseHandler.onCreate(DatabaseHandler.java:31)
06-29 07:38:52.080: E/AndroidRuntime(1057): at
android.database.sqlite.SQLiteOpenHelper.getDatabaseLocked(SQLiteOpenHelper.java:252)
06-29 07:38:52.080: E/AndroidRuntime(1057): at
android.database.sqlite.SQLiteOpenHelper.getWritableDatabase(SQLiteOpenHelper.java:164)
06-29 07:38:52.080: E/AndroidRuntime(1057): at
com.example.datbase.DatabaseHandler.addcontacts(DatabaseHandler.java:41)
06-29 07:38:52.080: E/AndroidRuntime(1057): at
com.example.datbase.MainActivity.onCreate(MainActivity.java:20)
06-29 07:38:52.080: E/AndroidRuntime(1057): at
android.app.Activity.performCreate(Activity.java:5243)
06-29 07:38:52.080: E/AndroidRuntime(1057): at
android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
06-29 07:38:52.080: E/AndroidRuntime(1057): at
android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2140)
06-29 07:38:52.080: E/AndroidRuntime(1057): ... 11 more
06-29 07:43:52.690: I/Process(1057): Sending signal. PID: 1057 SIG: 9
答案 0 :(得分：1)
这是Space之后的Key_ID问题。你需要提供适当的空间
String TABLE_CREATE="create "+TABLE_CONTACTS+" ("+KEY_ID+" integer primary key
autoincrement, "+
KEY_NAME+" text, "+KEY_PH_NO+" text;)";
此ID应该是_id，因为android在许多操作中使用此约定
private static String KEY_ID="_id";
答案 1 :(得分：1)
尝试这样创建table.code如下：
String TABLE_CREATE = "CREATE TABLE "+ TABLE_CONTACTS + " (" + KEY_ID + " INTEGER PRIMARY KEY AUTOINCREMENT,"+KEY_NAME+ " TEXT," +KEY_PH_NO+ " TEXT" + ")";
我希望这能解决你的问题。
答案 2 :(得分：0)
KEY_ID和＆＃34之间没有空格;整数主键自动增量＆＃34;所以添加一个空格
private static String KEY_ID="id ";或" integer primary key autoincrement