Sqlite 中使用PRAGMA 怎么执行及返回数据集

发布网友发布时间：2022-04-07 18:22

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懂视网时间：2022-04-07 22:43

package com.example.sqlitedemo; 2 3 import android.app.Activity; 4 import android.database.Cursor; 5 import android.database.sqlite.SQLiteDatabase; 6 import android.os.Bundle; 7 import android.util.Log; 8 import android.view.Menu; 9 import android.view.MenuItem; 10 import android.view.View; 11 12 public class MainActivity extends Activity { 13 SQLiteDatabase db = null; 14 public static String TAG = "sqlitedemo"; 15 @Override 16 protected void onCreate(Bundle savedInstanceState) { 17 super.onCreate(savedInstanceState); 18 setContentView(R.layout.activity_main); 19 20 db = SQLiteDatabase.openOrCreateDatabase(getFilesDir()+"/userinfo.db", null); 21 22 createTable(db); 23 } 24 public void insert(View v){ 25 insert(db); 26 } 27 public void delete(View v){ 28 delete(db); 29 } 30 public void update(View v){ 31 update(db); 32 } 33 public void query(View v){ 34 query(db); 35 } 36 37 private void update(SQLiteDatabase db){ 38 String update = "update user set password=? where id = ?"; 39 Object[] args = {"99999999", 5}; 40 db.execSQL(update, args); 41 } 42 43 private void delete(SQLiteDatabase db){ 44 String delete = "delete from user where id =?"; 45 Object[] args = {5}; 46 db.execSQL(delete, args); 47 } 48 49 private void query(SQLiteDatabase db){ 50 String query = "select * from user"; 51 Cursor resultSet = db.rawQuery(query, null); 52 53 int row = resultSet.getCount(); 54 Log.i(TAG, row+""); 55 56 while(resultSet.moveToNext()){ 57 int id = resultSet.getInt(0); 58 String username = resultSet.getString(1); 59 String password = resultSet.getString(2); 60 Log.i(TAG, id + "," +username+ "," + password); 61 62 } 63 64 } 65 private void insert(SQLiteDatabase db){ 66 String insert = "insert into user values(?,?,?)"; 67 Object[] args = {5, "user5", "55555555"}; 68 db.execSQL(insert, args); 69 } 70 71 private void createTable(SQLiteDatabase db){ 72 String createtable = "create table user(id int, name varchar(20),password char(8))"; 73 db.execSQL(createtable); 74 } 75 76 77 } MainActivity.java

 1 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 2  xmlns:tools="http://schemas.android.com/tools"
 3  android:layout_width="match_parent"
 4  android:layout_height="match_parent"
 5  android:orientation="vertical"
 6  android:paddingBottom="@dimen/activity_vertical_margin"
 7  android:paddingLeft="@dimen/activity_horizontal_margin"
 8  android:paddingRight="@dimen/activity_horizontal_margin"
 9  android:paddingTop="@dimen/activity_vertical_margin"
10  tools:context="com.example.sqlitedemo.MainActivity" >
11 
12 <TextView
13  android:layout_width="wrap_content"
14  android:layout_height="wrap_content"
15  android:text="@string/hello_world" />
16 
17 <Button
18  android:layout_width="fill_parent"
19  android:layout_height="wrap_content"
20  android:onClick="insert"
21  android:text="insert" />
22 
23 <Button
24  android:layout_width="fill_parent"
25  android:layout_height="wrap_content"
26  android:onClick="delete"
27  android:text="delete" />
28 
29 <Button
30  android:layout_width="fill_parent"
31  android:layout_height="wrap_content"
32  android:onClick="update"
33  android:text="update" />
34 
35 <Button
36  android:layout_width="fill_parent"
37  android:layout_height="wrap_content"
38  android:onClick="query"
39  android:text="query" />
40 
41 </LinearLayout>

activity_main.xml

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006_01SQLite_demo

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热心网友时间：2022-04-07 19:51

Delphi/Pascal code
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FDConnection1.DriverName := 'SQLite';
FDConnection1.Params.Add('Database=F:\Xe8\ls\FDDemo.sdb');

FDQuery1.Connection := FDConnection1;
DataSource1.DataSet := FDQuery1;
DBGrid1.DataSource := DataSource1;

FDQuery1.SQL.Text := 'PRAGMA table_info(Orders);'; // SQLite 非常好地支持了 SQL92 标准, 目前被忽略的仅有: http://www.sqlite.org/omitted.html

FDConnection1.Open();
FDQuery1.Open();