android 上的 SQLite 问题 - onCreate 或 insert
SQLite problems on android - onCreate or insert
我的应用程序的这一块让我有些伤心……我的 table 没有正确创建或者插入语句不正确。我遵循了本教程，该教程似乎得到了很好的解释 http://www.giantflyingsaucer.com/blog/?p=1342 但我似乎无法找到我的代码与他们的代码之间的区别。任何建议将不胜感激！
这是我的 MainActivity 代码：
私人 SQLiteIngAssistant sqlliteIngAssistant;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
sqlliteIngAssistant = new SQLiteIngAssistant(MainActivity.this);
sqlliteIngAssistant.openDB();
sqlliteIngAssistant.insertIng("Foo");
String[] autofillIngs = sqlliteIngAssistant.getAllIngNames();
}
这是我的 SQL 助手：
public class SQLiteIngAssistant extends SQLiteOpenHelper {
private static final String DB_NAME = "usingsqlite.db";
private static final int DB_VERSION_NUMBER = 1;
private static final String DB_TABLE_NAME = "ings";
private static final String DB_COLUMN_1_NAME = "ing_name";
private static final String DB_COLUMN_2_NAME = "cons";
private static final String DB_CREATE_SCRIPT = "create table " + DB_TABLE_NAME +
" (_id string primary key " + DB_COLUMN_1_NAME + ", " + DB_COLUMN_2_NAME + " text not null);)";
private SQLiteDatabase sqliteDBInstance = null;
public SQLiteIngAssistant(Context context){
super(context, DB_NAME, null, DB_VERSION_NUMBER);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion){
// TODO: Implement onUpgrade
}
@Override
public void onCreate(SQLiteDatabase sqliteDBInstance){
Log.i("onCreate", "Creating the database...");
sqliteDBInstance.execSQL(DB_CREATE_SCRIPT);
}
public void openDB() throws SQLException{
Log.i("openDB", "Checking sqliteDBInstance...");
if(this.sqliteDBInstance == null){
Log.i("openDB", "Creating sqliteDBInstance...");
this.sqliteDBInstance = this.getWritableDatabase();
}
}
public long insertIng(String Name){
ContentValues contentValues = new ContentValues();
contentValues.put(DB_COLUMN_1_NAME, Name);
return this.sqliteDBInstance.insert(DB_TABLE_NAME, null, contentValues);
}
public String[] getAllIngNames(){
Cursor cursor = this.sqliteDBInstance.query(DB_TABLE_NAME, new String[] {DB_COLUMN_1_NAME}, null, null, null, null, null);
if(cursor.getCount() >0){
String[] str = new String[cursor.getCount()];
int i = 0;
while (cursor.moveToNext()){
str[i] = cursor.getString(cursor.getColumnIndex(DB_COLUMN_1_NAME));
i++;
}
return str;
} else {
return new String[] {};
}
}
}
这是堆栈跟踪：
01-11 19:23:04.382 14630-14630/com.example.ciltkick.nom E/SQLiteDatabase﹕ Error inserting ing_name=Foo
android.database.sqlite.SQLiteException: table ings has no column named ing_name (code 1): , while compiling: INSERT INTO ings(ing_name) VALUES (?)
at android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method)
at android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:893)
at android.database.sqlite.SQLiteConnection.prepare(SQLiteConnection.java:504)
at android.database.sqlite.SQLiteSession.prepare(SQLiteSession.java:588)
at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:58)
at android.database.sqlite.SQLiteStatement.<init>(SQLiteStatement.java:31)
at android.database.sqlite.SQLiteDatabase.insertWithOnConflict(SQLiteDatabase.java:1475)
at android.database.sqlite.SQLiteDatabase.insert(SQLiteDatabase.java:1347)
at com.example.ciltkick.nom.SQLiteIngAssistant.insertIng(SQLiteIngAssistant.java:61)
at com.example.ciltkick.nom.MainActivity.onCreate(MainActivity.java:65)
at android.app.Activity.performCreate(Activity.java:5008)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2035)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2096)
at android.app.ActivityThread.access0(ActivityThread.java:138)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1207)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:213)
at android.app.ActivityThread.main(ActivityThread.java:4787)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:789)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:556)
at dalvik.system.NativeStart.main(Native Method)
01-11 19:23:04.422 14630-14630/com.example.ciltkick.nom E/AndroidRuntime﹕ FATAL EXCEPTION: main
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.ciltkick.nom/com.example.ciltkick.nom.MainActivity}: android.database.sqlite.SQLiteException: no such column: ing_name (code 1): , while compiling: SELECT ing_name FROM ings
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2071)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2096)
at android.app.ActivityThread.access0(ActivityThread.java:138)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1207)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:213)
at android.app.ActivityThread.main(ActivityThread.java:4787)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:789)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:556)
at dalvik.system.NativeStart.main(Native Method)
Caused by: android.database.sqlite.SQLiteException: no such column: ing_name (code 1): , while compiling: SELECT ing_name FROM ings
at android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method)
at android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:893)
at android.database.sqlite.SQLiteConnection.prepare(SQLiteConnection.java:504)
at android.database.sqlite.SQLiteSession.prepare(SQLiteSession.java:588)
at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:58)
at android.database.sqlite.SQLiteQuery.<init>(SQLiteQuery.java:37)
at android.database.sqlite.SQLiteDirectCursorDriver.query(SQLiteDirectCursorDriver.java:44)
at android.database.sqlite.SQLiteDatabase.rawQueryWithFactory(SQLiteDatabase.java:1322)
at android.database.sqlite.SQLiteDatabase.queryWithFactory(SQLiteDatabase.java:1169)
at android.database.sqlite.SQLiteDatabase.query(SQLiteDatabase.java:1040)
at android.database.sqlite.SQLiteDatabase.query(SQLiteDatabase.java:1208)
at com.example.ciltkick.nom.SQLiteIngAssistant.getAllIngNames(SQLiteIngAssistant.java:89)
at com.example.ciltkick.nom.MainActivity.onCreate(MainActivity.java:77)
at android.app.Activity.performCreate(Activity.java:5008)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2035)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2096)
at android.app.ActivityThread.access0(ActivityThread.java:138)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1207)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:213)
at android.app.ActivityThread.main(ActivityThread.java:4787)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:789)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:556)
at dalvik.system.NativeStart.main(Native Method)
private static final String DB_CREATE_SCRIPT = "create table " + DB_TABLE_NAME +
" (_id string primary key " + DB_COLUMN_1_NAME + ", " + DB_COLUMN_2_NAME + " text not null);)";
您在前一列 def 的 primary key 和后面的 DB_COLUMN_1_NAME 之间缺少一个 ,。
添加到那里后，卸载您的应用程序以重新创建数据库。
I want DB_COLUMN_1_NAME to be the name of the primary key, how can I do that?
将其更改为
private static final String DB_CREATE_SCRIPT = "create table " + DB_TABLE_NAME +
" (" + DB_COLUMN_1_NAME + " string primary key," + DB_COLUMN_2_NAME + " text not null);)";
这还会删除您之前拥有的主键列 _id。
or can I access a row without using the primary key?
是的，您可以按任何条件 select 行。请记住，如果您有 "a lot" 数据并使用非索引列进行查找，性能将很糟糕。主键列自动索引。
我的应用程序的这一块让我有些伤心……我的 table 没有正确创建或者插入语句不正确。我遵循了本教程，该教程似乎得到了很好的解释 http://www.giantflyingsaucer.com/blog/?p=1342 但我似乎无法找到我的代码与他们的代码之间的区别。任何建议将不胜感激！
这是我的 MainActivity 代码：
私人 SQLiteIngAssistant sqlliteIngAssistant;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
sqlliteIngAssistant = new SQLiteIngAssistant(MainActivity.this);
sqlliteIngAssistant.openDB();
sqlliteIngAssistant.insertIng("Foo");
String[] autofillIngs = sqlliteIngAssistant.getAllIngNames();
}
这是我的 SQL 助手：
public class SQLiteIngAssistant extends SQLiteOpenHelper {
private static final String DB_NAME = "usingsqlite.db";
private static final int DB_VERSION_NUMBER = 1;
private static final String DB_TABLE_NAME = "ings";
private static final String DB_COLUMN_1_NAME = "ing_name";
private static final String DB_COLUMN_2_NAME = "cons";
private static final String DB_CREATE_SCRIPT = "create table " + DB_TABLE_NAME +
" (_id string primary key " + DB_COLUMN_1_NAME + ", " + DB_COLUMN_2_NAME + " text not null);)";
private SQLiteDatabase sqliteDBInstance = null;
public SQLiteIngAssistant(Context context){
super(context, DB_NAME, null, DB_VERSION_NUMBER);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion){
// TODO: Implement onUpgrade
}
@Override
public void onCreate(SQLiteDatabase sqliteDBInstance){
Log.i("onCreate", "Creating the database...");
sqliteDBInstance.execSQL(DB_CREATE_SCRIPT);
}
public void openDB() throws SQLException{
Log.i("openDB", "Checking sqliteDBInstance...");
if(this.sqliteDBInstance == null){
Log.i("openDB", "Creating sqliteDBInstance...");
this.sqliteDBInstance = this.getWritableDatabase();
}
}
public long insertIng(String Name){
ContentValues contentValues = new ContentValues();
contentValues.put(DB_COLUMN_1_NAME, Name);
return this.sqliteDBInstance.insert(DB_TABLE_NAME, null, contentValues);
}
public String[] getAllIngNames(){
Cursor cursor = this.sqliteDBInstance.query(DB_TABLE_NAME, new String[] {DB_COLUMN_1_NAME}, null, null, null, null, null);
if(cursor.getCount() >0){
String[] str = new String[cursor.getCount()];
int i = 0;
while (cursor.moveToNext()){
str[i] = cursor.getString(cursor.getColumnIndex(DB_COLUMN_1_NAME));
i++;
}
return str;
} else {
return new String[] {};
}
}
}
这是堆栈跟踪：
01-11 19:23:04.382 14630-14630/com.example.ciltkick.nom E/SQLiteDatabase﹕ Error inserting ing_name=Foo
android.database.sqlite.SQLiteException: table ings has no column named ing_name (code 1): , while compiling: INSERT INTO ings(ing_name) VALUES (?)
at android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method)
at android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:893)
at android.database.sqlite.SQLiteConnection.prepare(SQLiteConnection.java:504)
at android.database.sqlite.SQLiteSession.prepare(SQLiteSession.java:588)
at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:58)
at android.database.sqlite.SQLiteStatement.<init>(SQLiteStatement.java:31)
at android.database.sqlite.SQLiteDatabase.insertWithOnConflict(SQLiteDatabase.java:1475)
at android.database.sqlite.SQLiteDatabase.insert(SQLiteDatabase.java:1347)
at com.example.ciltkick.nom.SQLiteIngAssistant.insertIng(SQLiteIngAssistant.java:61)
at com.example.ciltkick.nom.MainActivity.onCreate(MainActivity.java:65)
at android.app.Activity.performCreate(Activity.java:5008)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2035)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2096)
at android.app.ActivityThread.access0(ActivityThread.java:138)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1207)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:213)
at android.app.ActivityThread.main(ActivityThread.java:4787)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:789)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:556)
at dalvik.system.NativeStart.main(Native Method)
01-11 19:23:04.422 14630-14630/com.example.ciltkick.nom E/AndroidRuntime﹕ FATAL EXCEPTION: main
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.ciltkick.nom/com.example.ciltkick.nom.MainActivity}: android.database.sqlite.SQLiteException: no such column: ing_name (code 1): , while compiling: SELECT ing_name FROM ings
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2071)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2096)
at android.app.ActivityThread.access0(ActivityThread.java:138)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1207)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:213)
at android.app.ActivityThread.main(ActivityThread.java:4787)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:789)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:556)
at dalvik.system.NativeStart.main(Native Method)
Caused by: android.database.sqlite.SQLiteException: no such column: ing_name (code 1): , while compiling: SELECT ing_name FROM ings
at android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method)
at android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:893)
at android.database.sqlite.SQLiteConnection.prepare(SQLiteConnection.java:504)
at android.database.sqlite.SQLiteSession.prepare(SQLiteSession.java:588)
at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:58)
at android.database.sqlite.SQLiteQuery.<init>(SQLiteQuery.java:37)
at android.database.sqlite.SQLiteDirectCursorDriver.query(SQLiteDirectCursorDriver.java:44)
at android.database.sqlite.SQLiteDatabase.rawQueryWithFactory(SQLiteDatabase.java:1322)
at android.database.sqlite.SQLiteDatabase.queryWithFactory(SQLiteDatabase.java:1169)
at android.database.sqlite.SQLiteDatabase.query(SQLiteDatabase.java:1040)
at android.database.sqlite.SQLiteDatabase.query(SQLiteDatabase.java:1208)
at com.example.ciltkick.nom.SQLiteIngAssistant.getAllIngNames(SQLiteIngAssistant.java:89)
at com.example.ciltkick.nom.MainActivity.onCreate(MainActivity.java:77)
at android.app.Activity.performCreate(Activity.java:5008)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2035)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2096)
at android.app.ActivityThread.access0(ActivityThread.java:138)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1207)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:213)
at android.app.ActivityThread.main(ActivityThread.java:4787)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:789)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:556)
at dalvik.system.NativeStart.main(Native Method)
private static final String DB_CREATE_SCRIPT = "create table " + DB_TABLE_NAME + " (_id string primary key " + DB_COLUMN_1_NAME + ", " + DB_COLUMN_2_NAME + " text not null);)";
您在前一列 def 的 primary key 和后面的 DB_COLUMN_1_NAME 之间缺少一个 ,。
添加到那里后，卸载您的应用程序以重新创建数据库。
I want DB_COLUMN_1_NAME to be the name of the primary key, how can I do that?
将其更改为
private static final String DB_CREATE_SCRIPT = "create table " + DB_TABLE_NAME +
" (" + DB_COLUMN_1_NAME + " string primary key," + DB_COLUMN_2_NAME + " text not null);)";
这还会删除您之前拥有的主键列 _id。
or can I access a row without using the primary key?
是的，您可以按任何条件 select 行。请记住，如果您有 "a lot" 数据并使用非索引列进行查找，性能将很糟糕。主键列自动索引。