SQLite怎么创建Boolean数据类型

SQLite怎么创建Boolean数据类型

在eclipse中需要自定义创建表工具类：比如；1、写一个DBHelper继承自SQLiteOpenHelperpublicclassDBHelperextendsSQLiteOpenHelper{//数据库的版本privatefinalstaticintDB_VERSION=1//数据库名privatefinalstaticStringDB_NAME="ladeng.db"privateContextmContext//我们直接用super调用父类的构造方法，这样我们在实例化DBHelper的时候只需要传入一个上下文参数就可以了publicDBHelper(Contextcontext){super(context,DB_NAME,null,DB_VERSION)this.mContext=context}//数据库不存在的时候，调用这个方法@OverridepublicvoidonCreate(SQLiteDatabasedb){createTables(db,0,0)}//版本号发生变化的时候，调用这个方法@OverridepublicvoidonUpgrade(SQLiteDatabasedb,intoldVersion,intnewVersion){//1.删除原来的表//2.调用onCreate重新创建数据库}/***建表语句，只需要一行就能建一个表*/privatevoidcreateTables(SQLiteDatabasedb,intoldVersion,intnewVersion){//createTable(Movie.class)返回的是sql建表语句//db.execSQL(sql)执行这条建表语句db.execSQL(createTable(Movie.class))}/***如果没传表明的话，默认使用类名作为表明*@paramclazz实体类*@return*/privateStringcreateTable(Classclazz){returncreateTable(clazz,clazz.getSimpleName())}/***真正的建表方法*@paramclazz实体类*@paramtableName表明*@returnsql建表语句*/privateStringcreateTable(Classclazz,StringtableName){//实例化一个容器，用来拼接sql语句StringBuffersBuffer=newStringBuffer()//sql语句，第一个字段为_ID主键自增，这是通用的，所以直接写死sBuffer.append("createtableifnotexists"+tableName+""+"(_IDINTEGERPRIMARYKEYAUTOINCREMENTNOTNULL,")//得到实体类中所有的公有属性Field[]fields=clazz.getFields()//遍历所有的公有属性for(Fieldfield:fields){//如果属性不为_id的话，说明是新的字段if(!field.getName().equals("_id")){//得到属性的基本数据类型Stringtype=field.getType().getSimpleName()//如果是String类型的属性，就把字段类型设置为TEXTif(type.equals("String")){sBuffer.append(field.getName()+"TEXT,")//如果是int类型的属性，就把字段类型设置为INTEGER}elseif(type.equals("int")){sBuffer.append(field.getName()+"INTEGER,")}}}//将最后的逗号删除sBuffer.deleteCharAt(sBuffer.length()-1)//替换成)表明sql语句结束sBuffer.append(")")//返回这条sql语句returnsBuffer.toString()}}2、Movie实体类，实体类中的属性就是表中的字段publicclassMovie{publicStringtitlepublicintratingpublicStringyearpublicStringgenrepublicStringcountrypublicintprice}3、在MainActivity.java中添加如下代码publicclassMainActivityextendsActivity{ @Override protectedvoidonCreate(BundlesavedInstanceState){ super.onCreate(savedInstanceState)setContentView(R.layout.activity_main)//实例化我们的DBHelper DBHelperdbHelper=newDBHelper(this)//调用了这个方法后，DBHelper中的onCreate才会执行 dbHelper.getReadableDatabase()}}4、创建结果：

C#下SQLite *** 作驱动dll下载：System.Data.SQLite

C#使用SQLite步骤：

（1）新建一个project

（2）添加SQLite *** 作驱动dll引用

（3）使用API *** 作SQLite DataBase

using System

using System.Data.SQLite

namespace SQLiteSamples

{

class Program

{

//数据库连接

SQLiteConnection m_dbConnection

static void Main(string[] args)

{

Program p = new Program()

}

public Program()

{

createNewDatabase()

connectToDatabase()

createTable()

fillTable()

printHighscores()

}

//创建一个空的数据库

void createNewDatabase()

{

SQLiteConnection.CreateFile("MyDatabase.sqlite")

}

//创建一个连接到指定数据库

void connectToDatabase()

{

m_dbConnection = new SQLiteConnection("Data Source=MyDatabase.sqliteVersion=3")

m_dbConnection.Open()

}

//在指定数据库中创建一个table

void createTable()

{

string sql = "create table highscores (name varchar(20), score int)"

SQLiteCommand command = new SQLiteCommand(sql, m_dbConnection)

command.ExecuteNonQuery()

}

//插入一些数据

void fillTable()

{

string sql = "insert into highscores (name, score) values ('Me', 3000)"

SQLiteCommand command = new SQLiteCommand(sql, m_dbConnection)

command.ExecuteNonQuery()

sql = "insert into highscores (name, score) values ('Myself', 6000)"

command = new SQLiteCommand(sql, m_dbConnection)

command.ExecuteNonQuery()

sql = "insert into highscores (name, score) values ('And I', 9001)"

command = new SQLiteCommand(sql, m_dbConnection)

command.ExecuteNonQuery()

}

//使用sql查询语句，并显示结果

void printHighscores()

{

string sql = "select * from highscores order by score desc"

SQLiteCommand command = new SQLiteCommand(sql, m_dbConnection)

SQLiteDataReader reader = command.ExecuteReader()

while (reader.Read())

Console.WriteLine("Name: " + reader["name"] + "\tScore: " + reader["score"])

Console.ReadLine()

}

}

}

// 连接字符串 data source=d:\test.db3password=1234

SQLiteConnectionStringBuilder connStr = new SQLiteConnectionStringBuilder()

connStr.DataSource = @"d:\test.db3"

connStr.Password = "1234"

conn = new SQLiteConnection(connStr.ToString())

conn.Open()

// 插入数据

string SQL = "INSERT INTO test(k) VALUES(:k)"

SQLiteCommand cmd = conn.CreateCommand()

cmd.CommandText = SQL

// 取图标，准备插入到数据库BLOB字段

FileStream picStream = File.OpenRead(@"d:\1.bmp")

byte[] bArray = new byte[picStream.Length]

picStream.Read(bArray, 0, bArray.Length)

picStream.Close()

cmd.Parameters.Add("k", DbType.Binary).Value = bArray // BLOB

cmd.ExecuteNonQuery()

//取出数据

cmd.CommandText = "SELECT k FROM test"

System.Data.SQLite.SQLiteDataReader reader = cmd.ExecuteReader()

while (reader.Read())

{

MemoryStream streamImage = new MemoryStream(reader["k"] as byte[])

pictureBox1.Image = Image.FromStream(streamImage)

streamImage.Close()// 关闭流

}

reader.close()

conn.close()

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