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  • sql简单的语句

    选择:select * from table1 where 范围
    插入:insert into table1(field1,field2) values(value1,value2)
    删除:delete from table1 where 范围
    更新:update table1 set field1=value1 where 范围

    查找:select * from table1 where field1 like ’%value1%’ ---like的语法非常精妙,查资料!



    			String n=name.getText().toString();
    			String e=email.getText().toString();
    			//String add="insert into lgx_table(name,email) values('lgx','xxx')";
    			String add="insert into lgx_table(name,email) values(?,?

    )"; db.execSQL(add,new String[]{n,e});



    android简单的数据库创建和使用


    package com.example.dbdemo;
    
    import android.content.Context;
    import android.database.sqlite.SQLiteDatabase;
    import android.database.sqlite.SQLiteDatabase.CursorFactory;
    import android.database.sqlite.SQLiteOpenHelper;
    
    public class DataBd extends SQLiteOpenHelper {
    
    	public DataBd(Context context, String name, CursorFactory factory,
    			int version) {
    		super(context, name, factory, version);
    	}
    
    	@Override
    	public void onCreate(SQLiteDatabase db) {
    		db.execSQL("create table lgx_table(_id integer primary key autoincrement,name varchar(20), email varchar(50))");
    	}
    
    	@Override
    	public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    
    	}
    
    }
    




    package com.example.dbdemo;
    
    import android.app.Activity;
    import android.database.Cursor;
    import android.database.sqlite.SQLiteDatabase;
    import android.os.Bundle;
    import android.view.Menu;
    import android.view.MenuItem;
    import android.view.View;
    import android.view.View.OnClickListener;
    import android.widget.Button;
    import android.widget.EditText;
    import android.widget.TextView;
    
    public class MainActivity extends Activity {
    	DataBd dataBd;
    	SQLiteDatabase db;
    	EditText name,email;
    	TextView text;
    
    	@Override
    	protected void onCreate(Bundle savedInstanceState) {
    		super.onCreate(savedInstanceState);
    		setContentView(R.layout.activity_main);
    
    		dataBd = new DataBd(this, "lgx", null, 2);
    		db = dataBd.getReadableDatabase();
    		name=(EditText) findViewById(R.id.name);
    		email=(EditText) findViewById(R.id.email);
    		text=(TextView) findViewById(R.id.text);
    	}
    
    	public void dbClick(View v) {
    		switch (v.getId()) {
    		case R.id.add:
    			String n=name.getText().toString();
    			String e=email.getText().toString();
    			//String add="insert into lgx_table(name,email) values('lgx','xxx')";
    			String add="insert into lgx_table(name,email) values(?,?)";
    			db.execSQL(add,new String[]{n,e});
    			break;
    		case R.id.delete:
    			
    			break;
    		case R.id.update:
    
    			break;
    		case R.id.select:
    			String select="select * from lgx_table ";
    			//db.execSQL(select);
    			Cursor cursor=db.rawQuery(select, null);
    			while (cursor.moveToNext()) {
    				String name=cursor.getString(cursor.getColumnIndex("name"));
    				String email=cursor.getString(cursor.getColumnIndex("email"));
    				text.setText(name+"    "+email);
    			}
    			break;
    
    		default:
    			break;
    		}
    	}
    
    }
    



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  • 原文地址:https://www.cnblogs.com/jzssuanfa/p/6978871.html
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