无法从flex中的sqlite数据库获取数据
我正在flex 4.5中制作一个移动应用程序,我想获得人名和年龄,然后保存到sqlite数据库中。我的代码如下所示:无法从flex中的sqlite数据库获取数据,sqlite,flex4.5,flex-mobile,Sqlite,Flex4.5,Flex Mobile,我正在flex 4.5中制作一个移动应用程序,我想获得人名和年龄,然后保存到sqlite数据库中。我的代码如下所示: public var personNamesDB:File; public var dbConnection:SQLConnection; protected function createDatabase(event:FlexEvent):void { // TODO Auto-generated met
public var personNamesDB:File;
public var dbConnection:SQLConnection;
protected function createDatabase(event:FlexEvent):void
{
// TODO Auto-generated method stub
personNamesDB = File.applicationStorageDirectory.resolvePath("person.db");
dbConnection = new SQLConnection();
dbConnection.openAsync(personNamesDB, SQLMode.CREATE);
dbConnection.addEventListener(SQLEvent.OPEN, onDatabaseOpened);
dbConnection.addEventListener(SQLEvent.CLOSE, onDatabaseClosed);
}// end createDatabase method
protected function onDatabaseOpened(arshayEvent:SQLEvent):void
{
trace("DB Opened");
var statement:SQLStatement = new SQLStatement();
statement.sqlConnection = dbConnection;
statement.text = "CREATE TABLE IF NOT EXISTS personinfo(id INTEGER PRIMARY KEY AUTOINCREMENT, nameofperson TEXT, ageofperson TEXT)";
statement.execute();
// for showing saved city names in list on App start up
showSavedNames();
trace("table created");
}
现在插入数据代码的步骤是:
///////////////////////////////////
public var insertData:SQLStatement
protected function saveName():void
{
// SQLite Usage
insertData = new SQLStatement();
insertData.sqlConnection = dbConnection;
insertData.text = "INSERT INTO personinfo(nameofcity, ageofperson) VALUES(:nameofcity, :ageofperson)";
insertData.parameters[":nameofcity"] =nameInput.text;
insertData.parameters[":ageofperson"] = ageInput.text;
insertData.addEventListener(SQLEvent.RESULT, dataInsertedSuccess);
trace("Name " + nameInput.text);
insertData.execute();
showSavedNames();
}
protected function dataInsertedSuccess(event:SQLEvent):void
{
trace(insertData.getResult().data);
}
//////////////////////////////////////////////
public var selectQuery:SQLStatement;
protected function showSavedNames():void
{
selectQuery = new SQLStatement();
selectQuery.sqlConnection = dbConnection;
selectQuery.text = "SELECT * FROM personinfo ORDER BY nameofperson ASC";
selectQuery.addEventListener(SQLEvent.RESULT, showNamesInList);
selectQuery.execute();
}
protected function showNamesInList(event:SQLEvent):void
{
listOfAddedNames.dataProvider = new ArrayCollection(selectQuery.getResult().data);
}
列表控件的mxml代码为:
<s:List id="listOfAddedNames" width="345" height="100%" labelField="nameofperson"
click="get_names_data(event)"/>
在这一行:
trace("Age of selected Name is >> "+selectNameQuery.getResult().data.ageofperson);
没有从数据库中提取数据,trce显示“undefined”(未定义),请帮我解决这个问题,并告诉我如何根据人名列表中选定的姓名从ageofperson列中获取数据——提前感谢您,因为您打开了sqlite数据库异步模式,所以首先需要了解异步执行模型。 列名“nameofcity”的第二个问题是person表没有您声明的任何列。因此,我在这里修改为saveName()中的“nameofperson” 在调用saveName()的位置,请确保已调用“saveName()” 在sqlquery中的dataInsertedSuccess()中,仅当重新运行INSERT/UPDATE sql查询ie时返回受影响行的编号,仅返回整数值。因此,请始终insertData.getResult()。数据为空/未定义。如果运行SELECT sql查询,它将包含(s)个数据
public var personNamesDB:File;
public var dbConnection:SQLConnection;
protected function createDatabase(event:FlexEvent):void
{
// TODO Auto-generated method stub
personNamesDB = File.applicationStorageDirectory.resolvePath("person.db");
dbConnection = new SQLConnection();
dbConnection.openAsync(personNamesDB, SQLMode.CREATE);
dbConnection.addEventListener(SQLEvent.OPEN, onDatabaseOpened);
dbConnection.addEventListener(SQLEvent.CLOSE, onDatabaseClosed);
}// end createDatabase method
protected function onDatabaseOpened(arshayEvent:SQLEvent):void
{
trace("DB Opened");
var statement:SQLStatement = new SQLStatement();
statement.sqlConnection = dbConnection;
statement.text = "CREATE TABLE IF NOT EXISTS personinfo(id INTEGER PRIMARY KEY AUTOINCREMENT, nameofperson TEXT, ageofperson TEXT)";
statement.addEventListener(SQLEvent.RESULT ,function(event:SQLEvent):void
{
trace("table created");
// for showing saved city names in list on App start up
showSavedNames(); **//Need to call after get success event**
});
statement.execute();
}
public var insertData:SQLStatement
protected function saveName():void
{
// SQLite Usage
insertData = new SQLStatement();
insertData.sqlConnection = dbConnection;
insertData.text = "INSERT INTO personinfo(nameofperson, ageofperson) VALUES(:nameofperson, :ageofperson)";
insertData.parameters[":nameofperson"] = "Xyz";
insertData.parameters[":ageofperson"] = "27"
insertData.addEventListener(SQLEvent.RESULT, dataInsertedSuccess);
insertData.addEventListener(SQLErrorEvent.ERROR, function(event:SQLErrorEvent):void
{
//details "table 'personinfo' has no column named 'nameofcity'"
trace(event.error.message.toString());
// showSavedNames();
});
insertData.execute();
}
protected function dataInsertedSuccess(event:SQLEvent):void
{
trace("Success :: " + insertData.getResult().rowsAffected);
showSavedNames();
}
//////////////////////////////////////////////
public var selectQuery:SQLStatement;
protected function showSavedNames():void
{
selectQuery = new SQLStatement();
selectQuery.sqlConnection = dbConnection;
selectQuery.text = "SELECT * FROM personinfo ORDER BY nameofperson ASC";
selectQuery.addEventListener(SQLEvent.RESULT, showNamesInList);
selectQuery.execute();
}
protected function showNamesInList(event:SQLEvent):void
{
listOfAddedNames.dataProvider = new ArrayCollection(selectQuery.getResult().data);
}
public var selectNameQuery:SQLStatement;
protected function get_names_data(event:MouseEvent):void
{
//Need not to get ageofperson from db
Alert.show(listOfAddedNames.selectedItem.ageofperson);
//Any way continue your way
var currentName:String = listOfAddedNames.selectedItem.nameofperson;
selectNameQuery = new SQLStatement();
selectNameQuery.sqlConnection =dbConnection;
selectNameQuery.text = "SELECT ageofperson FROM personinfo WHERE nameofperson = '" + currentName + "'";
selectNameQuery.addEventListener(SQLEvent.RESULT, nowGotAge);
selectNameQuery.execute();
trace("current selected >> "+currentName);
}
protected function nowGotAge(event:SQLEvent):void
{
trace("Age of selected Name is >> "+selectNameQuery.getResult().data[0].ageofperson);
}
public var personNamesDB:File;
public var dbConnection:SQLConnection;
protected function createDatabase(event:FlexEvent):void
{
// TODO Auto-generated method stub
personNamesDB = File.applicationStorageDirectory.resolvePath("person.db");
dbConnection = new SQLConnection();
dbConnection.openAsync(personNamesDB, SQLMode.CREATE);
dbConnection.addEventListener(SQLEvent.OPEN, onDatabaseOpened);
dbConnection.addEventListener(SQLEvent.CLOSE, onDatabaseClosed);
}// end createDatabase method
protected function onDatabaseOpened(arshayEvent:SQLEvent):void
{
trace("DB Opened");
var statement:SQLStatement = new SQLStatement();
statement.sqlConnection = dbConnection;
statement.text = "CREATE TABLE IF NOT EXISTS personinfo(id INTEGER PRIMARY KEY AUTOINCREMENT, nameofperson TEXT, ageofperson TEXT)";
statement.addEventListener(SQLEvent.RESULT ,function(event:SQLEvent):void
{
trace("table created");
// for showing saved city names in list on App start up
showSavedNames(); **//Need to call after get success event**
});
statement.execute();
}
public var insertData:SQLStatement
protected function saveName():void
{
// SQLite Usage
insertData = new SQLStatement();
insertData.sqlConnection = dbConnection;
insertData.text = "INSERT INTO personinfo(nameofperson, ageofperson) VALUES(:nameofperson, :ageofperson)";
insertData.parameters[":nameofperson"] = "Xyz";
insertData.parameters[":ageofperson"] = "27"
insertData.addEventListener(SQLEvent.RESULT, dataInsertedSuccess);
insertData.addEventListener(SQLErrorEvent.ERROR, function(event:SQLErrorEvent):void
{
//details "table 'personinfo' has no column named 'nameofcity'"
trace(event.error.message.toString());
// showSavedNames();
});
insertData.execute();
}
protected function dataInsertedSuccess(event:SQLEvent):void
{
trace("Success :: " + insertData.getResult().rowsAffected);
showSavedNames();
}
//////////////////////////////////////////////
public var selectQuery:SQLStatement;
protected function showSavedNames():void
{
selectQuery = new SQLStatement();
selectQuery.sqlConnection = dbConnection;
selectQuery.text = "SELECT * FROM personinfo ORDER BY nameofperson ASC";
selectQuery.addEventListener(SQLEvent.RESULT, showNamesInList);
selectQuery.execute();
}
protected function showNamesInList(event:SQLEvent):void
{
listOfAddedNames.dataProvider = new ArrayCollection(selectQuery.getResult().data);
}
public var selectNameQuery:SQLStatement;
protected function get_names_data(event:MouseEvent):void
{
//Need not to get ageofperson from db
Alert.show(listOfAddedNames.selectedItem.ageofperson);
//Any way continue your way
var currentName:String = listOfAddedNames.selectedItem.nameofperson;
selectNameQuery = new SQLStatement();
selectNameQuery.sqlConnection =dbConnection;
selectNameQuery.text = "SELECT ageofperson FROM personinfo WHERE nameofperson = '" + currentName + "'";
selectNameQuery.addEventListener(SQLEvent.RESULT, nowGotAge);
selectNameQuery.execute();
trace("current selected >> "+currentName);
}
protected function nowGotAge(event:SQLEvent):void
{
trace("Age of selected Name is >> "+selectNameQuery.getResult().data[0].ageofperson);
}