函式增刪改查資料庫
阿新 • • 發佈:2019-02-18
package com.bwei.acid.dao; import android.content.ContentValues; import android.content.Context; import android.database.Cursor; import android.database.sqlite.SQLiteDatabase; import com.bwei.acid.db.MySqliteOpenHelper; public class StudentDao { private MySqliteOpenHelper helper; public StudentDao(Context context) { helper = new MySqliteOpenHelper(context); } // 增加 public void add(String name, int age) { SQLiteDatabase db = helper.getWritableDatabase(); ContentValues values = new ContentValues(); values.put("name", name); values.put("age", age); /** * 第一個引數表明 * 第二個引數是列 */ db.insert("student", null, values ); db.close(); } // 刪除 public void delete(String name) { SQLiteDatabase db = helper.getWritableDatabase(); db.delete("student", "name=?", new String[]{name}); db.close(); } // 修改 public void update(String name) { SQLiteDatabase db = helper.getWritableDatabase(); ContentValues values = new ContentValues(); values.put("name", name); values.put("age", 888); db.update("student", values , "name=?", new String[]{name}); db.close(); } // 查詢 public void query() { SQLiteDatabase db = helper.getWritableDatabase(); /** * Table 表名 Columens 要查詢的列 Selection 查詢條件 selectionArgs 查詢條件佔位符對應的內容 groupBy 分組判斷條件 Having 是否含有的判斷條件 orderBy 排序判斷條件 Limit 分頁查詢判斷條件 */ Cursor cursor = db.query("student", null, null, null, null, null, null, null); while(cursor.moveToNext()){ String name = cursor.getString(cursor.getColumnIndex("name")); int age = cursor.getInt(cursor.getColumnIndex("age")); System.out.println("name="+name+",age="+age); } } }