1.

写了一个简单得SQLite增删改查小程序，运行报错，检查了多遍，没检查出来。总是报错。报错如下

05-0403:09:46.4253496-3496/?E/libprocessgroup:failedtomakeandchown/acct/uid_10060:Read-onlyfilesystem05-0403:09:46.4253496-3496/?W/Zygote:createProcessGroupfailed,kernelmissingCONFIG_CGROUP_CPUACCT?05-0403:09:46.4253496-3496/?I/art:Late-enabling-Xcheck:jni05-0403:09:46.6393496-3496/com.hh.sqliteW/art:Failedexecv(/system/bin/dex2oat--runtime-arg-classpath--runtime-arg--debuggable--instruction-setx86--instruction-set-featuressmp,-ssse3,-sse4.1,-sse4.2,-avx,-avx2--runtime-arg-Xrelocate--boot-image/system/framework/boot.art--runtime-arg-Xms64m--runtime-arg-Xmx512m--instruction-set-variantx86--instruction-set-featuresdefault--dex-file/data/app/com.hh.sqlite-1/split_lib_dependencies_apk.apk--oat-file/data/dalvik-cache/x86/data@app@com.hh.sqlite-1@split_lib_dependencies_apk.apk@classes.dex)becausenon-0exitstatus05-0403:09:46.9043496-3496/com.hh.sqliteW/art:Failedexecv(/system/bin/dex2oat--runtime-arg-classpath--runtime-arg--debuggable--instruction-setx86--instruction-set-featuressmp,-ssse3,-sse4.1,-sse4.2,-avx,-avx2--runtime-arg-Xrelocate--boot-image/system/framework/boot.art--runtime-arg-Xms64m--runtime-arg-Xmx512m--instruction-set-variantx86--instruction-set-featuresdefault--dex-file/data/app/com.hh.sqlite-1/split_lib_slice_0_apk.apk--oat-file/data/dalvik-cache/x86/data@app@com.hh.sqlite-1@split_lib_slice_0_apk.apk@classes.dex)becausenon-0exitstatus05-0403:09:46.9443496-3496/com.hh.sqliteW/art:Failedexecv(/system/bin/dex2oat--runtime-arg-classpath--runtime-arg--debuggable--instruction-setx86--instruction-set-featuressmp,-ssse3,-sse4.1,-sse4.2,-avx,-avx2--runtime-arg-Xrelocate--boot-image/system/framework/boot.art--runtime-arg-Xms64m--runtime-arg-Xmx512m--instruction-set-variantx86--instruction-set-featuresdefault--dex-file/data/app/com.hh.sqlite-1/split_lib_slice_1_apk.apk--oat-file/data/dalvik-cache/x86/data@app@com.hh.sqlite-1@split_lib_slice_1_apk.apk@classes.dex)becausenon-0exitstatus05-0403:09:46.9823496-3496/com.hh.sqliteW/art:Failedexecv(/system/bin/dex2oat--runtime-arg-classpath--runtime-arg--debuggable--instruction-setx86--instruction-set-featuressmp,-ssse3,-sse4.1,-sse4.2,-avx,-avx2--runtime-arg-Xrelocate--boot-image/system/framework/boot.art--runtime-arg-Xms64m--runtime-arg-Xmx512m--instruction-set-variantx86--instruction-set-featuresdefault--dex-file/data/app/com.hh.sqlite-1/split_lib_slice_2_apk.apk--oat-file/data/dalvik-cache/x86/data@app@com.hh.sqlite-1@split_lib_slice_2_apk.apk@classes.dex)becausenon-0exitstatus05-0403:09:47.0283496-3496/com.hh.sqliteW/art:Failedexecv(/system/bin/dex2oat--runtime-arg-classpath--runtime-arg--debuggable--instruction-setx86--instruction-set-featuressmp,-ssse3,-sse4.1,-sse4.2,-avx,-avx2--runtime-arg-Xrelocate--boot-image/system/framework/boot.art--runtime-arg-Xms64m--runtime-arg-Xmx512m--instruction-set-variantx86--instruction-set-featuresdefault--dex-file/data/app/com.hh.sqlite-1/split_lib_slice_3_apk.apk--oat-file/data/dalvik-cache/x86/data@app@com.hh.sqlite-1@split_lib_slice_3_apk.apk@classes.dex)becausenon-0exitstatus05-0403:09:47.0823496-3496/com.hh.sqliteW/art:Failedexecv(/system/bin/dex2oat--runtime-arg-classpath--runtime-arg--debuggable--instruction-setx86--instruction-set-featuressmp,-ssse3,-sse4.1,-sse4.2,-avx,-avx2--runtime-arg-Xrelocate--boot-image/system/framework/boot.art--runtime-arg-Xms64m--runtime-arg-Xmx512m--instruction-set-variantx86--instruction-set-featuresdefault--dex-file/data/app/com.hh.sqlite-1/split_lib_slice_4_apk.apk--oat-file/data/dalvik-cache/x86/data@app@com.hh.sqlite-1@split_lib_slice_4_apk.apk@classes.dex)becausenon-0exitstatus05-0403:09:47.1443496-3496/com.hh.sqliteW/art:Failedexecv(/system/bin/dex2oat--runtime-arg-classpath--runtime-arg--debuggable--instruction-setx86--instruction-set-featuressmp,-ssse3,-sse4.1,-sse4.2,-avx,-avx2--runtime-arg-Xrelocate--boot-image/system/framework/boot.art--runtime-arg-Xms64m--runtime-arg-Xmx512m--instruction-set-variantx86--instruction-set-featuresdefault--dex-file/data/app/com.hh.sqlite-1/split_lib_slice_5_apk.apk--oat-file/data/dalvik-cache/x86/data@app@com.hh.sqlite-1@split_lib_slice_5_apk.apk@classes.dex)becausenon-0exitstatus05-0403:09:47.2303496-3496/com.hh.sqliteW/art:Failedexecv(/system/bin/dex2oat--runtime-arg-classpath--runtime-arg--debuggable--instruction-setx86--instruction-set-featuressmp,-ssse3,-sse4.1,-sse4.2,-avx,-avx2--runtime-arg-Xrelocate--boot-image/system/framework/boot.art--runtime-arg-Xms64m--runtime-arg-Xmx512m--instruction-set-variantx86--instruction-set-featuresdefault--dex-file/data/app/com.hh.sqlite-1/split_lib_slice_6_apk.apk--oat-file/data/dalvik-cache/x86/data@app@com.hh.sqlite-1@split_lib_slice_6_apk.apk@classes.dex)becausenon-0exitstatus05-0403:09:47.2853496-3496/com.hh.sqliteW/art:Failedexecv(/system/bin/dex2oat--runtime-arg-classpath--runtime-arg--debuggable--instruction-setx86--instruction-set-featuressmp,-ssse3,-sse4.1,-sse4.2,-avx,-avx2--runtime-arg-Xrelocate--boot-image/system/framework/boot.art--runtime-arg-Xms64m--runtime-arg-Xmx512m--instruction-set-variantx86--instruction-set-featuresdefault--dex-file/data/app/com.hh.sqlite-1/split_lib_slice_7_apk.apk--oat-file/data/dalvik-cache/x86/data@app@com.hh.sqlite-1@split_lib_slice_7_apk.apk@classes.dex)becausenon-0exitstatus05-0403:09:47.3263496-3496/com.hh.sqliteW/art:Failedexecv(/system/bin/dex2oat--runtime-arg-classpath--runtime-arg--debuggable--instruction-setx86--instruction-set-featuressmp,-ssse3,-sse4.1,-sse4.2,-avx,-avx2--runtime-arg-Xrelocate--boot-image/system/framework/boot.art--runtime-arg-Xms64m--runtime-arg-Xmx512m--instruction-set-variantx86--instruction-set-featuresdefault--dex-file/data/app/com.hh.sqlite-1/split_lib_slice_8_apk.apk--oat-file/data/dalvik-cache/x86/data@app@com.hh.sqlite-1@split_lib_slice_8_apk.apk@classes.dex)becausenon-0exitstatus05-0403:09:47.3643496-3496/com.hh.sqliteW/art:Failedexecv(/system/bin/dex2oat--runtime-arg-classpath--runtime-arg--debuggable--instruction-setx86--instruction-set-featuressmp,-ssse3,-sse4.1,-sse4.2,-avx,-avx2--runtime-arg-Xrelocate--boot-image/system/framework/boot.art--runtime-arg-Xms64m--runtime-arg-Xmx512m--instruction-set-variantx86--instruction-set-featuresdefault--dex-file/data/app/com.hh.sqlite-1/split_lib_slice_9_apk.apk--oat-file/data/dalvik-cache/x86/data@app@com.hh.sqlite-1@split_lib_slice_9_apk.apk@classes.dex)becausenon-0exitstatus05-0403:09:47.3663496-3496/com.hh.sqliteW/System:ClassLoaderreferencedunknownpath:/data/app/com.hh.sqlite-1/lib/x8605-0403:09:47.3893496-3496/com.hh.sqliteI/InstantRun:startinginstantrunserver:ismainprocess05-0403:09:47.4953496-3537/com.hh.sqliteD/OpenGLRenderer:UseEGL_SWAP_BEHAVIOR_PRESERVED:true05-0403:09:47.7793496-3537/com.hh.sqliteD/libEGL:loaded/system/lib/egl/libEGL_emulation.soloaded/system/lib/egl/libGLESv1_CM_emulation.so05-0403:09:47.7893496-3537/com.hh.sqliteD/libEGL:loaded/system/lib/egl/libGLESv2_emulation.so05-0403:09:47.8233496-3537/com.hh.sqliteI/OpenGLRenderer:InitializedEGL,version1.405-0403:09:47.9533496-3537/com.hh.sqliteW/EGL_emulation:eglSurfaceAttribnotimplemented05-0403:09:47.9533496-3537/com.hh.sqliteW/OpenGLRenderer:FailedtosetEGL_SWAP_BEHAVIORonsurface0xe7fbcf00,errorEGL_SUCCESS05-0403:09:48.3893496-3496/com.hh.sqliteI/Choreographer:Skipped46frames!Theapplicationmaybedoingtoomuchworkonitsmainthread.05-0403:10:20.5643496-3537/com.hh.sqliteW/EGL_emulation:eglSurfaceAttribnotimplemented05-0403:10:20.5643496-3537/com.hh.sqliteW/OpenGLRenderer:FailedtosetEGL_SWAP_BEHAVIORonsurface0xe7fbd4e0,errorEGL_SUCCESS05-0403:10:21.1763496-3537/com.hh.sqliteE/Surface:getSlotFromBufferLocked:unknownbuffer:0xf3d57e8005-0403:10:27.6263496-3496/com.hh.sqliteE/SQLiteLog:(1)near"creat":syntaxerror05-0403:10:27.6273496-3496/com.hh.sqliteD/AndroidRuntime:ShuttingdownVM---------beginningofcrash05-0403:10:27.6273496-3496/com.hh.sqliteE/AndroidRuntime:FATALEXCEPTION:mainProcess:com.hh.sqlite,PID:3496java.lang.IllegalStateException:Couldnotexecutemethodforandroid:onClickatandroid.view.View$DeclaredOnClickListener.onClick(View.java:4452)atandroid.view.View.performClick(View.java:5198)atandroid.view.View$PerformClick.run(View.java:21147)atandroid.os.Handler.handleCallback(Handler.java:739)atandroid.os.Handler.dispatchMessage(Handler.java:95)atandroid.os.Looper.loop(Looper.java:148)atandroid.app.ActivityThread.main(ActivityThread.java:5417)atjava.lang.reflect.Method.invoke(NativeMethod)atcom.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)atcom.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)Causedby:java.lang.reflect.InvocationTargetExceptionatjava.lang.reflect.Method.invoke(NativeMethod)atandroid.view.View$DeclaredOnClickListener.onClick(View.java:4447)atandroid.view.View.performClick(View.java:5198)atandroid.view.View$PerformClick.run(View.java:21147)atandroid.os.Handler.handleCallback(Handler.java:739)atandroid.os.Handler.dispatchMessage(Handler.java:95)atandroid.os.Looper.loop(Looper.java:148)atandroid.app.ActivityThread.main(ActivityThread.java:5417)atjava.lang.reflect.Method.invoke(NativeMethod)atcom.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)atcom.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)Causedby:android.database.sqlite.SQLiteException:near"creat":syntaxerror(code1):,whilecompiling:creattableperson(idintegerprimarykeyautoincrement,namevarchar(20)numbervarchar(20))atandroid.database.sqlite.SQLiteConnection.nativePrepareStatement(NativeMethod)atandroid.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:887)atandroid.database.sqlite.SQLiteConnection.prepare(SQLiteConnection.java:498)atandroid.database.sqlite.SQLiteSession.prepare(SQLiteSession.java:588)atandroid.database.sqlite.SQLiteProgram.init(SQLiteProgram.java:58)atandroid.database.sqlite.SQLiteStatement.init(SQLiteStatement.java:31)atandroid.database.sqlite.SQLiteDatabase.executeSql(SQLiteDatabase.java:1674)atandroid.database.sqlite.SQLiteDatabase.execSQL(SQLiteDatabase.java:1605)atcom.hh.sqlite.PersonSQLiteOpenHelper.onCreate(PersonSQLiteOpenHelper.java:21)atandroid.database.sqlite.SQLiteOpenHelper.getDatabaseLocked(SQLiteOpenHelper.java:251)atandroid.database.sqlite.SQLiteOpenHelper.getWritableDatabase(SQLiteOpenHelper.java:163)atcom.hh.sqlite.PersonDao.add(PersonDao.java:17)atcom.hh.sqlite.MainActivity.add(MainActivity.java:28)atjava.lang.reflect.Method.invoke(NativeMethod)atandroid.view.View$DeclaredOnClickListener.onClick(View.java:4447)atandroid.view.View.performClick(View.java:5198)atandroid.view.View$PerformClick.run(View.java:21147)atandroid.os.Handler.handleCallback(Handler.java:739)atandroid.os.Handler.dispatchMessage(Handler.java:95)atandroid.os.Looper.loop(Looper.java:148)atandroid.app.ActivityThread.main(ActivityThread.java:5417)atjava.lang.reflect.Method.invoke(NativeMethod)atcom.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)atcom.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)05-0403:10:31.0013496-3496/com.hh.sqliteI/Process:Sendingsignal.PID:3496SIG:92.

我的程序：ativity_main.xml

?xmlversion"1.0"encoding"utf-8"?LinearLayoutxmlns:android"http://schemas.android.com/apk/res/android"android:layout_width"match_parent"android:layout_height"match_parent"android:orientation"vertical"EditTextandroid:id"@+id/et_id"android:layout_width"fill_parent"android:layout_height"wrap_content"android:ems"10"android:hint"请输入id"android:inputType"number"/EditTextandroid:id"@+id/et_name"android:layout_width"fill_parent"android:layout_height"wrap_content"android:ems"10"android:hint"请输入姓名"android:inputType"textPersonName"requestFocus//EditTextEditTextandroid:id"@+id/et_number"android:layout_width"fill_parent"android:layout_height"wrap_content"android:ems"10"android:hint"请输入账号"android:inputType"number"/LinearLayoutandroid:layout_width"match_parent"android:layout_height"wrap_content"Buttonandroid:id"@+id/btn_add"android:layout_width"wrap_content"android:layout_height"wrap_content"android:onClick"add"android:text"保存"/Buttonandroid:id"@+id/btn_update"android:layout_width"wrap_content"android:layout_height"wrap_content"android:onClick"update"android:text"修改"/Buttonandroid:id"@+id/btn_delete"android:layout_width"wrap_content"android:layout_height"wrap_content"android:onClick"delete"android:text"删除"/Buttonandroid:id"@+id/btn_find"android:layout_width"wrap_content"android:layout_height"wrap_content"android:onClick"find"android:text"查找"//LinearLayout/LinearLayout3.

MainActivity.java

packagecom.hh.sqlite;importandroid.app.Activity;importandroid.support.v7.app.AppCompatActivity;importandroid.os.Bundle;importandroid.view.View;importandroid.widget.EditText;importandroid.widget.Toast;publicclassMainActivityextendsActivity{privateEditTextet_id;privateEditTextet_number;privateEditTextet_name;@OverrideprotectedvoidonCreate(BundlesavedInstanceState){super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);et_id(EditText)findViewById(R.id.et_id);et_name(EditText)findViewById(R.id.et_name);et_number(EditText)findViewById(R.id.et_number);}publicvoidadd(Viewview){PersonDaopersonDaonewPersonDao(this);longidpersonDao.add(et_name.getText().toString().trim(),et_number.getText().toString().trim());//有问题Toast.makeText(this,"添加信息为，id为"+id,Toast.LENGTH_SHORT).show();}publicvoidupdate(Viewview){PersonDaopersonDaonewPersonDao(this);intcountpersonDao.update(Long.parseLong(et_id.getText().toString().trim()),et_name.getText().toString().trim(),et_number.getText().toString().trim());Toast.makeText(this,"成功修改"+count+"条信息",Toast.LENGTH_SHORT).show();}publicvoiddelete(Viewview){PersonDaopersonDaonewPersonDao(this);intcountpersonDao.delete(Long.parseLong(et_id.getText().toString().trim()));Toast.makeText(this,"成功删除"+count+"条信息",Toast.LENGTH_SHORT).show();}publicvoidfind(Viewview){PersonDaopersonDaonewPersonDao(this);booleanresultpersonDao.find(Long.parseLong(et_id.getText().toString().trim()));if(result){Toast.makeText(this,"查询信息成功",Toast.LENGTH_SHORT).show();}else{Toast.makeText(this,"查询信息失败",Toast.LENGTH_SHORT).show();}}}4.

PersonDao.java

packagecom.hh.sqlite;importandroid.content.ContentValues;importandroid.content.Context;importandroid.database.Cursor;importandroid.database.sqlite.SQLiteDatabase;publicclassPersonDao{privatePersonSQLiteOpenHelperhelper;publicPersonDao(Contextcontext){//构造方法helpernewPersonSQLiteOpenHelper(context);}publiclongadd(Stringname,Stringnumber){//错误修改前：下面这句话报错-，修改后无错误SQLiteDatabasedbhelper.getWritableDatabase();//SQLiteDatabase类,该类是一个数据库访问类，封装了一系列数据库操作的API，可以对数据进行增删改查操作。ContentValuesvaluesnewContentValues();values.put("name",name);values.put("number",number);longiddb.insert("person",null,values);//调用insert方法，table是person表格db.close();returnid;//通过调用add得到他的id值}publicintupdate(longid,Stringname,Stringnumber){SQLiteDatabasedbhelper.getWritableDatabase();ContentValuesvaluesnewContentValues();values.put("name",name);values.put("number",number);intcountdb.update("person",values,"id?",newString[]{String.valueOf(id)});db.close();returncount;}publicintdelete(longid){SQLiteDatabasedbhelper.getWritableDatabase();intcountdb.delete("person","id?",newString[]{String.valueOf(id)});db.close();returncount;}publicbooleanfind(longid){SQLiteDatabasedbhelper.getReadableDatabase();Cursorcursordb.query("person",null,"id?",newString[]{String.valueOf(id)},null,null,null);booleanresultcursor.moveToNext();cursor.close();db.close();returnresult;}}5.

PersonSQLiteOpenHelper.java

packagecom.hh.sqlite;importandroid.content.Context;importandroid.database.sqlite.SQLiteDatabase;importandroid.database.sqlite.SQLiteOpenHelper;publicclassPersonSQLiteOpenHelperextendsSQLiteOpenHelper{//还需要写一个构造方法,需要调用父类的构造方法publicPersonSQLiteOpenHelper(Contextcontext){//需要上下文所以添加Contextsuper(context,"person.db",null,1);//我们要创建的数据库名称person.db；版本号为1；游标null}@OverridepublicvoidonCreate(SQLiteDatabasedb){StringBuffersq1newStringBuffer();//创建了一个字符串对象sq1.append("creattableperson(");//！！！！！！！！！！！！！！！根本错误第一个错误将creat改为create！！！！sq1.append("idintegerprimarykeyautoincrement,");sq1.append("namevarchar(20)");//！！！！！！！！！！第二个错误！！！！！！！！！！sq1.append("numbervarchar(20))");db.execSQL(sq1.toString());//错误修改前：这句话报错-，修改后无错误}@OverridepublicvoidonUpgrade(SQLiteDatabasedb,intoldVersion,intnewVersion){db.execSQL("altertablepersonaddaccountvarchar(20)default1000");//更新的时候，添加了一个account字段}}6.

Person.java

packagecom.hh.sqlite;publicclassPerson{privatelongid;privateStringname;privateStringnumber;publicPerson(longid,Stringname,Stringnumber){super();this.idid;this.namename;this.numbernumber;}publiclonggetId(){returnid;}publicvoidsetId(longid){this.idid;}publicStringgetName(){returnname;}publicvoidsetName(Stringname){this.namename;}publicStringgetNumber(){returnnumber;}publicvoidsetNumber(Stringnumber){this.numbernumber;}}7.

错误：在文中标出！

8.

运算结果：