SQLite

用户保存常量的类

public class Person_constant {
public final static String TABLE_NAME_PERSON = "t_person";
public final static String TABLE_NAME_PERSON_id = "id";
public final static String TABLE_NAME_PERSON_NAME = "name";
public final static String TABLE_NAME_PERSON_AGE = "age";

}

用户保存数据Person类

public class Person {
private int id;
private String name;
private int age;

public Person() {
}

public Person(int id, String name, int age) {
this.id = id;
this.name = name;
this.age = age;
}

public int getId() {
return id;
}

public void setId(int id) {
this.id = id;
}

public String getName() {
return name;
}

public void setName(String name) {
this.name = name;
}

public int getAge() {
return age;
}

public void setAge(int age) {
this.age = age;
}

@Override
public String toString() {
return "Person{" +
"id=" + id +
", name='" + name + '\'' +
", age=" + age +
'}';
}
}

工具类

public class SQLiteOpenHelperDemo extends SQLiteOpenHelper {
private static SQLiteOpenHelperDemo sqLiteOpenHelperDemo;
private final static String DATABASE_NAME = "MyDataBase.db";

private final static int VERSION = 1;

private SQLiteOpenHelperDemo(Context context) {
super(context, DATABASE_NAME, null, VERSION);
System.out.println(sqLiteOpenHelperDemo);
}

public static SQLiteOpenHelperDemo getInstance(Context context) {
if (sqLiteOpenHelperDemo == null) {
sqLiteOpenHelperDemo = new SQLiteOpenHelperDemo(context);
}
return sqLiteOpenHelperDemo;
}

@Override
public void onCreate(SQLiteDatabase db) {
StringBuffer creat_table = new StringBuffer();
creat_table.append("CREATE TABLE IF NOT EXISTS ")
.append(Person_constant.TABLE_NAME_PERSON)
.append("(")
.append(Person_constant.TABLE_NAME_PERSON_id)
.append(" INTEGER PRIMARY KEY AUTOINCREMENT,")
.append(Person_constant.TABLE_NAME_PERSON_NAME)
.append(" VARCHAR(20) UNIQUE,")
.append(Person_constant.TABLE_NAME_PERSON_AGE)
.append(" INTEGER DEFAULT 1 CHECK(age BETWEEN 1 AND 150))");
db.execSQL(creat_table.toString());

StringBuffer insert_table=new StringBuffer();
insert_table.append("INSERT INTO ")
.append(Person_constant.TABLE_NAME_PERSON)
.append(" VALUES")
.append("(null,?,?)");
db.execSQL(insert_table.toString(),new Object[]{"张三",20});
db.execSQL(insert_table.toString(),new Object[]{"李四",21});
db.execSQL(insert_table.toString(),new Object[]{"王五",22});
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

}
}

接口类`

public interface DAO {
void insert(Person person);
void update(Person person);
void delete(Person person);
List<Person> select();
List<Person> select(Integer... id);
List<Person> select(String... name);
}
实现接口的业务类

//

// long insert(String table,String nullColumnHack,ContentValues values)

// table:插入的表名

// nullColumnHack:当values为null或者size()为0时，强行null时的是数据列列名，不能是主键与非空列

// values:插入的一行记录数据，内部封装了HashMap

//

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

// table:要更新的表名

// values：要更新的数据，内部封装了HashMap

// whereClause:满足该条件的记录会被更新(占位符)

// whereArgs：为whereArgs字句传入参数(代替占位符)

//

//delete(String table,String whereClause,String[] whereArgs)

// table:要删除的表名

// whereClause：满足该条件的记录会被删除（占位符）

// whereArgs:为whereClause传入参数(代替占位符)

//

//Cursor query(boolean distinct,是否要去除重复记录

// String table,要查询数据的表名

// String[] columns,要查询的列名

// String whereClause,查询条件子条件（占位符）

// String[] selectionArgs,为占位符传入参数

// String groupBy,控制分组

// String having,对分组过滤

// String orderBy,对记录排序

// String limit)进行分页

//

//

public class DAOBean implements DAO {

private SQLiteOpenHelperDemo sqLiteOpenHelperDemo;

public DAOBean(Context context) {
this.sqLiteOpenHelperDemo = SQLiteOpenHelperDemo.getInstance(context);
}

@Override
public void insert(Person person) {
SQLiteDatabase db = sqLiteOpenHelperDemo.getWritableDatabase();

// String insert_table =

// “INSERT INTO ”

// + Person_constant.TABLE_NAME_PERSON

// + ” VALUES(null,?,?)”;

// db.execSQL(insert_table, new Object[]{person.getName(), person.getAge()});

ContentValues contentValues=new ContentValues();

contentValues.put(“id”,person.getId());

contentValues.put(“name”,person.getName());

contentValues.put(“age”,person.getAge());

db.insert(Person_constant.TABLE_NAME_PERSON,null,contentValues);

}

@Override
public void update(Person person) {
SQLiteDatabase db = sqLiteOpenHelperDemo.getWritableDatabase();
String update = "UPDATE "
+ Person_constant.TABLE_NAME_PERSON
+ " SET "
+ Person_constant.TABLE_NAME_PERSON_NAME
+ "=?,"
+ Person_constant.TABLE_NAME_PERSON_AGE
+ "=?"
+ " WHERE "
+ Person_constant.TABLE_NAME_PERSON_id
+ "=?";

db.execSQL(update, new Object
a277
[]{person.getName(), person.getAge(), person.getId()});
}

@Override
public void delete(Person person) {
SQLiteDatabase db = sqLiteOpenHelperDemo.getWritableDatabase();
String delete = "DELETE FROM "
+ Person_constant.TABLE_NAME_PERSON
+ " WHERE "
+ Person_constant.TABLE_NAME_PERSON_id
+ "=?";
db.execSQL(delete, new Object[]{person.getId()});
}

@Override
public List<Person> select() {
SQLiteDatabase db = sqLiteOpenHelperDemo.getWritableDatabase();
String selectAll = "SELECT *FROM " + Person_constant.TABLE_NAME_PERSON;
List<Person> list = new ArrayList<>();
Cursor cursor = null;
try {
cursor = db.rawQuery(selectAll, null);
while (cursor.moveToNext()) {
Person person = new Person(
cursor.getInt(cursor.getColumnIndex("id")),
cursor.getString(cursor.getColumnIndex("name")),
cursor.getInt(cursor.getColumnIndex("age"))
);
list.add(person);
}
return list;
} catch (Exception e) {
e.printStackTrace();
} finally {
if (db != null && db.isOpen()) {
db.close();
db = null;
}
if (cursor != null && !cursor.isClosed()) {
cursor.close();
cursor = null;
}
}
return null;
}

@Override
public List<Person> select(Integer... id) {
SQLiteDatabase db = sqLiteOpenHelperDemo.getWritableDatabase();
List<Person> list = new ArrayList<>();

StringBuffer sb = new StringBuffer();
for (int ids : id) {
sb.append("?,");
}
sb.deleteCharAt(sb.length() - 1);
String select = "SELECT *FROM "
+ Person_constant.TABLE_NAME_PERSON
+ " WHERE id in (" + sb.toString() + ")";
String[] st = new String[id.length];
for (int i = 0; i < id.length; i++) {
st[i] = String.valueOf(id[i]);
}
Cursor cursor = null;
try {
cursor = db.rawQuery(select, st);
while (cursor.moveToNext()) {
Person p = new Person(
cursor.getInt(cursor.getColumnIndex("id")),
cursor.getString(cursor.getColumnIndex("name")),
cursor.getInt(cursor.getColumnIndex("age"))
);
list.add(p);
}
return list;
} catch (Exception e) {
e.printStackTrace();
} finally {
if (db != null && db.isOpen()) {
db.close();
db = null;
}
if (cursor != null && !cursor.isClosed()) {
cursor.close();
cursor = null;
}
}
return null;
}

@Override
public List<Person> select(String... name) {
List<Person> list = new ArrayList<>();
SQLiteDatabase db = sqLiteOpenHelperDemo.getWritableDatabase();
StringBuffer sb = new StringBuffer();
for (String names : name) {
sb.append("?,");
}
sb.deleteCharAt(sb.length() - 1);

String selectName = "SELECT *FROM "
+ Person_constant.TABLE_NAME_PERSON
+ " WHERE name in (" + sb.toString() + ")";
Cursor cursor = null;
try {
cursor = db.rawQuery(selectName, name);
while (cursor.moveToNext()) {
Person p = new Person(
cursor.getInt(cursor.getColumnIndex("id")),
cursor.getString(cursor.getColumnIndex("name")),
cursor.getInt(cursor.getColumnIndex("age"))
);
list.add(p);
}
return list;
} catch (Exception e) {
e.printStackTrace();
} finally {
if (db != null && db.isOpen()) {
db.close();
db = null;
}
if (cursor != null && !cursor.isClosed()) {
cursor.close();
cursor = null;
}
}
return null;
}

@Override
public List<Person> selectPagination(int pageNo, int pageSize) {

return null;
}

}