本文共 12891 字，大约阅读时间需要 42 分钟。

1.创建表格

第一步，先创建一个类，然后继承 SQLiteOpenHelper这个类，并且实现抽象方法。

第二步，创建一个构造方法。

第三步，在Oncreat方法里面建表。

activity继承个人写的baseActivity，读者可用自己的代替，本人的里面涉及到一个顶部返回的按钮，只要在布局中去掉即可，同时把activity设置标题的的代码去掉

package com.pad.untek.mes.mespda.test.activitys.sqlite;import android.content.Context;import android.database.sqlite.SQLiteDatabase;import android.database.sqlite.SQLiteOpenHelper;/** * Sam on 2020/8/5. */public class MySQLiteOpenHelper extends SQLiteOpenHelper {    public MySQLiteOpenHelper(Context context, String name, SQLiteDatabase.CursorFactory factory, int version) {        super(context, name, factory, version);    }    @Override    public void onCreate(SQLiteDatabase db) {        //在这个方法里面来建表        String sql = "create table student(id integer primary key autoincrement,stuid varchar(50), stuname varchar(20),stuclass varchar(20))";        db.execSQL(sql);// 这一步就完成了加载驱动和建立连接    }    @Override    public void onUpgrade(SQLiteDatabase sqLiteDatabase, int i, int i1) {    }}

activity里面调用，实现增删改查

import android.content.ContentValues;import android.content.Context;import android.database.Cursor;import android.database.sqlite.SQLiteDatabase;import android.os.Bundle;import android.support.v7.widget.LinearLayoutManager;import android.support.v7.widget.RecyclerView;import android.view.View;import android.widget.TextView;import com.pad.untek.mes.mespda.test.R;import com.pad.untek.mes.mespda.test.activitys.BaseActivity;import com.pad.untek.mes.mespda.test.view.ClearEditText;import java.util.ArrayList;import java.util.List;import butterknife.BindView;import butterknife.ButterKnife;import butterknife.OnClick;public class SQLiteTestActivity extends BaseActivity {    //替换个人BaseActivity需去掉textTitle    @BindView(R.id.text_title)    TextView textTitle;    @BindView(R.id.cet_name)    ClearEditText cetName;    @BindView(R.id.cet_id)    ClearEditText cetId;    @BindView(R.id.cet_class)    ClearEditText cetClass;    @BindView(R.id.tv_add)    TextView tvAdd;    @BindView(R.id.tv_delete)    TextView tvDelete;    @BindView(R.id.tv_change)    TextView tvChange;    @BindView(R.id.tv_query)    TextView tvQuery;    @BindView(R.id.rv_list)    RecyclerView rvList;    Context context;    String studentId;    String studentName;    String studentClass;    String contents = "";    MySQLiteOpenHelper mySQLiteOpenHelper;    SQLiteDatabase database;    List
   
     studentBeanList = new ArrayList<>();    SQLiteQueryDataAdapter adapter;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_sqlite_test);        ButterKnife.bind(this);        context = this;        initView();    }    private void initView() {        rvList.setLayoutManager(new LinearLayoutManager(this));        //替换个人BaseActivity需去掉textTitle        textTitle.setText("SQLitet操作");//设置页面标题        //建表        mySQLiteOpenHelper = new MySQLiteOpenHelper(context, "students.db", null, 1);        database = mySQLiteOpenHelper.getWritableDatabase();    }    @OnClick({R.id.tv_add, R.id.tv_delete, R.id.tv_change, R.id.tv_query})    public void onClick(View view) {        switch (view.getId()) {            case R.id.tv_add:                if (isEmpty(3)) {                    addData();                    queryData("");//添加后显示所有数据                }                showDataList(studentBeanList);                break;            case R.id.tv_delete:                if (isEmpty(4)) {                    deleteData(studentId);                    queryData("");//删除后显示剩余所有数据                }                showDataList(studentBeanList);                break;            case R.id.tv_change:                if (isEmpty(1)) {                    String[] strings = new String[]{studentId, studentName, studentClass};                    updateData(strings);                    queryData("");//修改后显示所有数据                }                showDataList(studentBeanList);                break;            case R.id.tv_query:                if (isEmpty(2)) {                    queryData(contents);//查询后显示所有数据                }                showDataList(studentBeanList);                break;        }    }    /**     * 增加data     */    private void addData() {        queryData("");        if (studentBeanList.size() > 0) {            for (int i = 0; i < studentBeanList.size(); i++) {                if (studentId.equals(studentBeanList.get(i).stuid)) {                    toastSpek("学生ID已存在！");                    return;                }            }        }        //create student data        ContentValues contentValues = new ContentValues();        contentValues.put(SQLiteConstants.stuid, studentId);        contentValues.put(SQLiteConstants.stuname, studentName);        contentValues.put(SQLiteConstants.stuclass, studentClass);        //insert to students table        database.insert(SQLiteConstants.tabelName, null, contentValues);        toastSpek("添加学生成功！");    }    /**     * 根据ID删除data     *     * @param studentId     */    private void deleteData(String studentId) {        queryData("");        if (studentBeanList.size() > 0) {            for (int i = 0; i < studentBeanList.size(); i++) {                if (studentId.equals(studentBeanList.get(i).stuid)) {                    database.delete(SQLiteConstants.tabelName, SQLiteConstants.SQL_QUERY_STU_ID, new String[]{studentId});                    toastSpek("删除学生成功！");                    return;                }            }            toastSpek("学生ID不存在！");        }    }    /**     * 根据ID修改data     *     * @param strings     */    private void updateData(String[] strings) {        queryData("");        if (studentBeanList.size() > 0) {            for (int i = 0; i < studentBeanList.size(); i++) {                if (studentId.equals(studentBeanList.get(i).stuid)) {                    ContentValues contentValues = new ContentValues();                    if (!strings[1].isEmpty()) contentValues.put(SQLiteConstants.stuname, strings[1]);                    if (!strings[2].isEmpty()) contentValues.put(SQLiteConstants.stuclass, strings[2]);                    database.update(SQLiteConstants.tabelName, contentValues, SQLiteConstants.SQL_QUERY_STU_ID, new String[]{strings[0]});                    toastSpek("修改学生成功！");                    return;                }            }            toastSpek("学生ID不存在！");        }    }    /**     * 根据条件查询data     *     * @param contents 查询条件  如果都为空，查询所有数据；有值就进行条件查询     */    private void queryData(String contents) {        studentBeanList.clear();//清空查询前的数据        String content = "%" + contents + "%";        //条件查询        if (!contents.isEmpty()) {            Cursor cursor; //通过游标获取数据            cursor = database.query(SQLiteConstants.tabelName, null,                    SQLiteConstants.SQL_QUERY_STU_ID                            + SQLiteConstants.SQL_QUERY_OR                            + SQLiteConstants.SQL_QUERY_STU_NAME                            + SQLiteConstants.SQL_QUERY_OR                            + SQLiteConstants.SQL_QUERY_STU_CLASS,                    new String[]{content, content, content}, null, null, null);            if (cursor != null) {                while (cursor.moveToNext()) {                    StudentBean student = new StudentBean();                    student.id = cursor.getInt(0);                    student.stuid = cursor.getString(1);                    student.stuname = cursor.getString(2);                    student.stuclass = cursor.getString(3);                    studentBeanList.add(student);                }            }            cursor.close();        } else {//查询全部            Cursor cursor; //通过游标获取数据            cursor = database.query(SQLiteConstants.tabelName, null, null, null, null, null, null);            if (cursor != null) {                while (cursor.moveToNext()) {                    StudentBean student = new StudentBean();                    student.id = cursor.getInt(0);                    student.stuid = cursor.getString(1);                    student.stuname = cursor.getString(2);                    student.stuclass = cursor.getString(3);                    studentBeanList.add(student);                }            }            cursor.close();        }    }    /**     * 展现data     *     * @param studentBeanList     */    private void showDataList(List
    
      studentBeanList) {        if (studentBeanList.size() > 0) {            if (adapter == null) {                rvList.setAdapter(new SQLiteQueryDataAdapter(context, studentBeanList));            } else {                adapter.updateDataList(studentBeanList);            }        } else {            toastSpek("没有相关数据！");        }    }    /**     * @param type 需要判断的类型     * @return     */    private boolean isEmpty(int type) {        contents = "";        studentId = cetId.getText().toString().trim();        studentName = cetName.getText().toString().trim();        studentClass = cetClass.getText().toString().trim();        if (type == 3) {//增加data时候，都必填            if (studentId.isEmpty() || studentName.isEmpty() || studentClass.isEmpty()) {                toastSpek("name，ID和class都不能为空！");                return false;            }        }        if (type == 2) {            if (!studentId.isEmpty()) contents = studentId;            if (!studentName.isEmpty()) contents = studentName;            if (!studentClass.isEmpty()) contents = studentClass;            return true;        }        if (type == 1) {//修改data时候，ID不能为空            if (studentId.isEmpty()) {                toastSpek("ID不能为空！");                return false;            } else if (!studentName.isEmpty() || !studentClass.isEmpty()) {                return true;            } else {                toastSpek("请填写修改内容！");                return false;            }        }        if (type == 4) {//删除data时候，ID不能为空            if (studentId.isEmpty()) {                toastSpek("ID不能为空！");                return false;            }        }        return true;    }}
    
   

SQLiteConstants关于表名，字段名等可以统一规范

/** * Sam on 2020/8/5. */public class SQLiteConstants {    public static String SQL_QUERY_STU_ID = "stuid like ?";    public static String SQL_QUERY_STU_NAME = "stuname like ?";    public static String SQL_QUERY_STU_CLASS = "stuclass like ?";    public static String SQL_QUERY_OR = " or ";    public static String SQL_QUERY_AND = " and ";    public static String tabelName = "student";//table name    public static String stuid = "stuid";//student id    public static String stuname = "stuname";//student name    public static String stuclass = "stuclass";//student class}

数据bean

/** * Sam on 2020/8/5. */public class StudentBean {    public int id;    public String stuid;    public String stuname;    public String stuclass;}

adapter

import android.content.Context;import android.support.v7.widget.RecyclerView;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.TextView;import com.pad.untek.mes.mespda.test.R;import java.util.List;import butterknife.BindView;import butterknife.ButterKnife;/** * Sam on 2020/8/5. */public class SQLiteQueryDataAdapter extends RecyclerView.Adapter
   
     {    Context context;    List
    
      studentBeanList;    public SQLiteQueryDataAdapter(Context context, List
     
       studentBeanList) {        this.context = context;        this.studentBeanList = studentBeanList;    }    public void updateDataList(List
      
        studentBeanList) {        this.studentBeanList = studentBeanList;        notifyDataSetChanged();    }    @Override    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {        ViewMyHolder holder = new ViewMyHolder(LayoutInflater.from(context).inflate(R.layout.adapter_sqlite_query_data, parent, false));        return holder;    }    @Override    public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {        ViewMyHolder viewMyHolder = (ViewMyHolder) holder;        viewMyHolder.tvStuid.setText(studentBeanList.get(position).stuid);        viewMyHolder.tvStuname.setText(studentBeanList.get(position).stuname);        viewMyHolder.tvStuclass.setText(studentBeanList.get(position).stuclass);    }    @Override    public int getItemCount() {        return studentBeanList.size();    }    @Override    public long getItemId(int position) {        return position;    }    @Override    public int getItemViewType(int position) {        return position;    }    class ViewMyHolder extends RecyclerView.ViewHolder {        @BindView(R.id.tv_stuid)        TextView tvStuid;        @BindView(R.id.tv_stuname)        TextView tvStuname;        @BindView(R.id.tv_stuclass)        TextView tvStuclass;        public ViewMyHolder(View itemView) {            super(itemView);            ButterKnife.bind(this,itemView);        }    }}
      
     
    
   

布局文件，com.pad.untek.mes.mespda.test.view.ClearEditText是自定义输入框，可换成Android自带EditText

转载地址：http://zwrgf.baihongyu.com/