SQLite数据库操作

Android SQLiteOpenHelper SQLite数据库增删改查操作

 
 

  
  
importandroid.content.ContentValues; 
  
  
importandroid.content.Context; 
  
  
importandroid.database.Cursor; 
  
  
importandroid.database.sqlite.SQLiteDatabase; 
  
  
importandroid.database.sqlite.SQLiteOpenHelper; 
  
  

  
  
publicclassToDoDBextendsSQLiteOpenHelper{ 
  
  
privatefinalstaticStringDATABASE_NAME="todo_db"; 
  
  
privatefinalstaticintDATABASE_VERSION=1; 
  
  
privatefinalstaticStringTABLE_NAME="todo_table"; 
  
  
publicfinalstaticStringFIELD_id="_id"; 
  
  
publicfinalstaticStringFIELD_TEXT="todo_text"; 
  
  

  
  
publicToDoDB(Contextcontext){ 
  
  
super(context,DATABASE_NAME,null,DATABASE_VERSION); 
  
  
} 
  
  

  
  
@Override
  
  
publicvoidonCreate(SQLiteDatabasedb){ 
  
  
/*建立table*/
  
  
Stringsql="CREATETABLE"+TABLE_NAME+"("+FIELD_id 
  
  
+"INTEGERprimarykeyautoincrement,"+""+FIELD_TEXT 
  
  
+"text)"; 
  
  
db.execSQL(sql); 
  
  
} 
  
  

  
  
@Override
  
  
publicvoidonUpgrade(SQLiteDatabasedb,intoldVersion,intnewVersion){ 
  
  
Stringsql="DROPTABLEIFEXISTS"+TABLE_NAME; 
  
  
db.execSQL(sql); 
  
  
onCreate(db); 
  
  
} 
  
  

  
  
publicCursorselect(){ 
  
  
SQLiteDatabasedb=this.getReadableDatabase(); 
  
  
Cursorcursor=db 
  
  
.query(TABLE_NAME,null); 
  
  
returncursor; 
  
  
} 
  
  

  
  
publiclonginsert(Stringtext){ 
  
  
SQLiteDatabasedb=this.getWritableDatabase(); 
  
  
/*将新增的值放入ContentValues*/
  
  
ContentValuescv=newContentValues(); 
  
  
cv.put(FIELD_TEXT,text); 
  
  
longrow=db.insert(TABLE_NAME,cv); 
  
  
returnrow; 
  
  
} 
  
  

  
  
publicvoiddelete(intid){ 
  
  
SQLiteDatabasedb=this.getWritableDatabase(); 
  
  
Stringwhere=FIELD_id+"=?"; 
  
  
String[]whereValue={Integer.toString(id)}; 
  
  
db.delete(TABLE_NAME,where,whereValue); 
  
  
} 
  
  

  
  
publicvoidupdate(intid,Stringtext){ 
  
  
SQLiteDatabasedb=this.getWritableDatabase(); 
  
  
Stringwhere=FIELD_id+"=?"; 
  
  
String[]whereValue={Integer.toString(id)}; 
  
  
/*将修改的值放入ContentValues*/
  
  
ContentValuescv=newContentValues(); 
  
  
cv.put(FIELD_TEXT,text); 
  
  
db.update(TABLE_NAME,cv,whereValue); 
  
  
} 
  
  
}
 
 

（编辑：李大同）

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