Tuesday, May 22, 2012

KirSQLite - Flex AIR Database Manager: Part 21

In this tutorial we'll add the ability to delete columns from tables.

Go to the col_b_delete button and set its click event handler to deleteColumn():

<s:Button id="col_b_delete" label="Delete selected" enabled="{columnList.selectedItems.length > 0}" click="deleteColumn();" />

The function will use a similar method to addColumn() - we're going to create a backup table with the needed columns, copy all the needed data from the initial table to the backup table, then drop the initial table and rename the backup to the initial name.

In the beginning of deleteColumn(), set emphasized property of col_b_update to false, declare a String variable that holds the name of the currently selected table:

col_b_update.emphasized = false;
var prevTableName:String = tableTree.selectedItem.@label;

After that, we load the schema of the connection object to retreive the SQL query used to create this table. Then we extract the columns with all their parameters and split them into an array. Then we get the index of the currently selected column in the table and store it in currentIndex variable:

connection.loadSchema(SQLTableSchema, tableTree.selectedItem.@label, tableTree.selectedItem.@databaseName);
var schema:SQLSchemaResult = connection.getSchemaResult();
var fullSQL:String = schema.tables[0].sql;
// extract the text inside the ( )
fullSQL = fullSQL.substring( fullSQL.indexOf("(") + 1 , fullSQL.lastIndexOf(")") );
// split all columns into an array
var columns:Array = fullSQL.split(",");
// get the currently selected index
var currentIndex:int = columnList.selectedIndex;

Now we can create the backup table. First, create the name for the backup, using the same method as in previous tutorial:

// Create backup
var backupName:String = "backup";
while (!tableIsUnique(backupName)) {
backupName += "0";
}

Then we create a statement that creates a new table with this name. We use the columns array, from which we delete the unneeded column before applying it to the query.

var bstat:SQLStatement = new SQLStatement();
bstat.sqlConnection = connection;
var sqlText:String = "CREATE TABLE " + selectedDatabase + "." + backupName + " (";
columns.splice(currentIndex, 1);
if (columns.length == 0) {
Alert.show("Can't make a table completely empty! Leave at least one column.", "Nope");
return;
}
sqlText += String(columns);
sqlText += ");";
bstat.text = sqlText;
lastStatement(sqlText);
bstat.execute();

Copy the data to the backup table from the initial table. Use the INSERT INTO command, and to list the column names we'll use the function columnNames(), that we used in the previous tutorial. Except that this time we will add a paremeter to this function - currentIndex.

// Copy data to backup
var cstat:SQLStatement = new SQLStatement();
cstat.sqlConnection = connection;
cstat.text = "INSERT INTO " + selectedDatabase + "." + backupName + " (" + columnNames(currentIndex) + ") SELECT " + columnNames(currentIndex) + " FROM " + selectedDatabase + "." + tableTree.selectedItem.@label;
cstat.execute();

By adding the parameter we tell the function that this index is an exception and should not be included in the outputted string. Edit the columnNames function to add an optional exception parameter. In the function we create a new array and push the names of the columns into the array if the index of that item does not equal the exception index passed as the parameter:

private function columnNames(exception:int = -1):String {
var r:String = "";
var array:Array = [];
for (var i:int = 0; i < columnData.length; i++) {
if (i != exception) array.push(columnData[i].name);
}
r = String(array);
return r;
}

After the data has been copied, we can drop the existing table:

// Drop existing table
var dstat:SQLStatement = new SQLStatement();
dstat.sqlConnection = connection;
dstat.text = "DROP TABLE " + selectedDatabase + "." + tableTree.selectedItem.@label;
dstat.execute();

And then we can rename the backup to the initial table name:

// Rename backup table to initial name
var rstat:SQLStatement = new SQLStatement();
rstat.sqlConnection = connection;
rstat.text = "ALTER TABLE " + selectedDatabase + "." + backupName + " RENAME TO " + prevTableName
rstat.execute();
tableSelect();

Full function:

private function deleteColumn():void {
col_b_update.emphasized = false;
var prevTableName:String = tableTree.selectedItem.@label;

connection.loadSchema(SQLTableSchema, tableTree.selectedItem.@label, tableTree.selectedItem.@databaseName);
var schema:SQLSchemaResult = connection.getSchemaResult();
var fullSQL:String = schema.tables[0].sql;
// extract the text inside the ( )
fullSQL = fullSQL.substring( fullSQL.indexOf("(") + 1 , fullSQL.lastIndexOf(")") );
// split all columns into an array
var columns:Array = fullSQL.split(",");
// get the currently selected index
var currentIndex:int = columnList.selectedIndex;

// Create backup
var backupName:String = "backup";
while (!tableIsUnique(backupName)) {
backupName += "0";
}
var bstat:SQLStatement = new SQLStatement();
bstat.sqlConnection = connection;
var sqlText:String = "CREATE TABLE " + selectedDatabase + "." + backupName + " (";
columns.splice(currentIndex, 1);
if (columns.length == 0) {
Alert.show("Can't make a table completely empty! Leave at least one column.", "Nope");
return;
}
sqlText += String(columns);
sqlText += ");";
bstat.text = sqlText;
lastStatement(sqlText);
bstat.execute();

// Copy data to backup
var cstat:SQLStatement = new SQLStatement();
cstat.sqlConnection = connection;
cstat.text = "INSERT INTO " + selectedDatabase + "." + backupName + " (" + columnNames(currentIndex) + ") SELECT " + columnNames(currentIndex) + " FROM " + selectedDatabase + "." + tableTree.selectedItem.@label;
cstat.execute();

// Drop existing table
var dstat:SQLStatement = new SQLStatement();
dstat.sqlConnection = connection;
dstat.text = "DROP TABLE " + selectedDatabase + "." + tableTree.selectedItem.@label;
dstat.execute();

// Rename backup table to initial name
var rstat:SQLStatement = new SQLStatement();
rstat.sqlConnection = connection;
rstat.text = "ALTER TABLE " + selectedDatabase + "." + backupName + " RENAME TO " + prevTableName
rstat.execute();
tableSelect();
}

Full code:

<?xml version="1.0" encoding="utf-8"?>
<s:WindowedApplication xmlns:fx="http://ns.adobe.com/mxml/2009"
                       xmlns:s="library://ns.adobe.com/flex/spark"
                       xmlns:mx="library://ns.adobe.com/flex/mx" showStatusBar="false">
   
<s:menu>
<mx:FlexNativeMenu dataProvider="{windowMenu}" showRoot="false" labelField="@label" keyEquivalentField="@key" itemClick="menuSelect(event);" />
</s:menu>

<fx:Declarations>
<fx:XML id="windowMenu">
<root>
<menuitem label="Database">
<menuitem id="newdb" label="New" key="n" controlKey="true" />
<menuitem id="opendb" label="Open" key="o" controlKey="true" />
<menuitem id="savedb" label="Save a copy" key="s" controlKey="true" enabled="{tableTree.selectedItems.length>0}"/>
</menuitem>
<menuitem label="Table">
<menuitem id="newtable" label="Add table" key="t" controlKey="true" enabled="{tableTree.selectedItems.length>0}"/>
<menuitem id="droptable" label="Drop table" key="d" controlKey="true" enabled="{isTableSelected}"/>
</menuitem>
</root>
</fx:XML>
<fx:XMLList id="dbData">
</fx:XMLList>
<mx:ArrayCollection id="tableData">
</mx:ArrayCollection>
<mx:ArrayCollection id="columnData">
</mx:ArrayCollection>
<mx:ArrayCollection id="conflictTypes">
<fx:String>---</fx:String>
<fx:String>ABORT</fx:String>
<fx:String>FAIL</fx:String>
<fx:String>IGNORE</fx:String>
<fx:String>ROLLBACK</fx:String>
<fx:String>REPLACE</fx:String>
</mx:ArrayCollection>
<mx:ArrayCollection id="dataTypes">
<fx:String>NONE</fx:String>
<fx:String>INTEGER</fx:String>
<fx:String>TEXT</fx:String>
<fx:String>REAL</fx:String>
<fx:String>NUMERIC</fx:String>
</mx:ArrayCollection>
<mx:AdvancedDataGridColumn id="checkboxColumn" headerText=" " width="30" sortable="false" draggable="false" resizable="false" editable="false">
<mx:itemRenderer>
<fx:Component>
<mx:Box width="30" horizontalAlign="center">
<mx:CheckBox selected="@{data.sel}" />
</mx:Box>
</fx:Component>
</mx:itemRenderer>
</mx:AdvancedDataGridColumn>
<mx:TitleWindow id="newTableWindow" title="Create new table" close="closeNewTableWindow();" showCloseButton="true">
<s:VGroup>
<s:HGroup width="100%" verticalAlign="middle">
<s:Label>Table name: </s:Label>
<s:TextInput id="newTableName" />
</s:HGroup>
<s:Button click="createNewTable();" label="Create" width="100%" />
</s:VGroup>
</mx:TitleWindow>
<mx:TitleWindow id="historyWindow" title="SQL History" close="closeHistoryWindow();" showCloseButton="true">
<mx:Box width="100%" height="100%" paddingLeft="10" paddingRight="10" paddingTop="10" paddingBottom="10">
<s:TextArea id="historyText" width="100%" height="100%" editable="false" />
</mx:Box>
</mx:TitleWindow>
</fx:Declarations>

<fx:Script>
<![CDATA[
import flash.data.SQLConnection;
import flash.data.SQLResult;
import flash.data.SQLSchema;
import flash.data.SQLSchemaResult;
import flash.data.SQLStatement;
import flash.errors.SQLError;
import flash.events.Event;
import flash.events.MouseEvent;
import flash.events.SQLEvent;
import flash.filesystem.File;
import flash.net.FileFilter;
import flash.net.FileReference;
import flash.net.Responder;
import flash.ui.ContextMenu;
import flash.ui.ContextMenuItem;
import mx.collections.ArrayCollection;
import mx.controls.advancedDataGridClasses.AdvancedDataGridColumn;
import mx.controls.Alert;
import mx.events.CloseEvent;
import mx.events.FlexNativeMenuEvent;
import mx.managers.PopUpManager;

private var connection:SQLConnection = new SQLConnection();
private var selectedDatabase:String = "";
[Bindable]
private var isTableSelected:Boolean = false;
private var sqlHistory:Array = [];

private function selectAllChange(evt:Event):void {
var i:int;
if (evt.currentTarget.selected) {
for (i = 0; i < tableData.length; i++) {
tableData[i].sel = true;
}
} else
if (!evt.currentTarget.selected) {
for (i = 0; i < tableData.length; i++) {
tableData[i].sel = false;
}
}
tableGrid.invalidateDisplayList();
tableGrid.invalidateList();
}

private function menuSelect(evt:FlexNativeMenuEvent):void {
(evt.item.@id == "newdb")?(newDatabase()):(void);
(evt.item.@id == "opendb")?(openDatabase()):(void);
(evt.item.@id == "newtable")?(newTable()):(void);
(evt.item.@id == "droptable")?(dropTable()):(void);
(evt.item.@id == "savedb")?(saveCopy()):(void);
}

private function newDatabase():void {
var file:File = File.desktopDirectory.resolvePath("Untitled");
file.addEventListener(Event.SELECT, newSelect);
file.browseForSave("Choose where to save the database");
var newDB:XML;
var statement:SQLStatement = new SQLStatement();
function newSelect(evt:Event):void {
if (file.exists) {
Alert.show("File already exists, cannot overwrite.", "Nope");
return;
}
file.nativePath += ".db";
var n:String = parseDatabase(file);
loadDataSchema(n);
}
}

private function openDatabase():void {
var file:File = new File();
file.browseForOpen("Open database", [new FileFilter("Databases", "*.db"), new FileFilter("All files", "*")]);
file.addEventListener(Event.SELECT, openSelect);

function openSelect(evt:Event):void {
var n:String = parseDatabase(file, true);
loadDataSchema(n);
}
}

private function saveCopy():void {
var databasePath:String;
if (selectedDatabase == "main") databasePath = dbData.db[0].@path;
if (selectedDatabase != "main") {
var newNum:int = Number(selectedDatabase.replace("db", ""));
var newInd:int;
for (var i:int = 0; i < dbData.db.length(); i++) {
if (dbData.db[i].@numid == newNum) {
newInd = i;
break;
}
}
databasePath = dbData.db[newInd].@path;
}
var file:File = new File(databasePath);
file.browseForSave("Save copy of database");
file.addEventListener(Event.SELECT, onCopySelect);
function onCopySelect(evt:Event):void {
if(notAlreadyOpen(file)){
var initFile:File = new File(databasePath);
initFile.copyTo(file, true);
}else {
Alert.show("Cannot overwrite a file that is currently open.", "Nope");
}
}
}

private function loadDataSchema(name:String):void {
if (name != "") {
connection.loadSchema(null, null, name, true, new Responder(schemaSuccess, schemaError));
function schemaSuccess(evt:SQLSchemaResult):void {
// Schema found! Now parsing:
var result:SQLSchemaResult = evt;
// Adding tables:
var nid:Number = (name=="main")?(1):(Number(name.replace("db", "")));
var dataNode:XMLList = dbData.db.(@numid == nid);
dataNode.setChildren(<placeholder/>);
delete dataNode.placeholder;
for (var i:int = 0; i < result.tables.length; i++) {
var newTable:XML = new XML(<tb/>);
newTable.@label = result.tables[i].name;
newTable.@isBranch = false;
newTable.@databaseName = name;
dataNode.appendChild(newTable);
}
}
function schemaError(evt:SQLError):void {
// Alert.show("Database is empty");
}
isTableSelected = false;
}
}

private function parseDatabase(file:File, needCheck:Boolean = false):String {
var ret:String = "";
if (!needCheck || file.exists) {
if(!needCheck || notAlreadyOpen(file)){
var newDB:XML;
if (dbData.db.length() == 0) {
connection.open(file);
dbData = new XMLList(<root></root>);
newDB = <db/>
newDB.@label = file.name;
newDB.@numid = 1;
newDB.@isBranch = true;
newDB.@path = file.nativePath;
dbData[0].appendChild(newDB);
ret = "main";
}else
if (dbData.db.length() > 0) {
var newnum:int = dbData.db.length() + 1;
connection.attach("db"+newnum.toString(), file);
newDB = <db/>
newDB.@label = file.name;
newDB.@numid = newnum.toString();
newDB.@isBranch = true;
newDB.@path = file.nativePath;
dbData[0].appendChild(newDB);
ret = "db" + newnum.toString();
}}else {
Alert.show("Database already opened.", "Error");
}
}else {
Alert.show("File not found.", "Error");
}
return ret;
}

private function notAlreadyOpen(file:File):Boolean{ 
var r:Boolean = true;
for (var i:int = 0; i < dbData.db.length(); i++) {
if (file.nativePath == dbData.db[i].@path) {
r = false;
}
}
return r;
}

private function tableSelect():void {
saveTableButton.emphasized = false;
columnData = new ArrayCollection([]);
if(col_name!=null){
col_name.text = "";
col_data.selectedIndex = 0;
col_key.selected = false;
col_auto.selected = false;
col_unique.selected = false;
col_null.selected = false;
col_default.text = "";
col_conflict.selectedIndex = 0;
}
if (tableTree.selectedItem.@isBranch) {
isTableSelected = false;
var dataname:String;
if (tableTree.selectedItem.@numid == 1) dataname = "main";
if (tableTree.selectedItem.@numid > 1) dataname = "db" + tableTree.selectedItem.@numid;
selectedDatabase = dataname;
}
if (tableTree.selectedItem.@isBranch == false) {
isTableSelected = true;
selectedDatabase = tableTree.selectedItem.@databaseName;
tableData = new ArrayCollection([]);
var newColumns:Array = [checkboxColumn];
connection.loadSchema(SQLTableSchema, tableTree.selectedItem.@label, tableTree.selectedItem.@databaseName);
var schema:SQLSchemaResult = connection.getSchemaResult();
for (var i:int = 0; i < schema.tables[0].columns.length; i++) {
columnData.addItem({name:schema.tables[0].columns[i].name});
var aColumn:AdvancedDataGridColumn = new AdvancedDataGridColumn();
aColumn.headerText = schema.tables[0].columns[i].name;
aColumn.dataField = "db_" + schema.tables[0].columns[i].name;
if (schema.tables[0].columns[i].autoIncrement) aColumn.editable = false;
if (schema.tables[0].columns[i].primaryKey) tableTree.selectedItem.@primaryKeyColumn = schema.tables[0].columns[i].name;
newColumns.push(aColumn);
}
tableGrid.columns = newColumns;
var stat:SQLStatement = new SQLStatement();
stat.sqlConnection = connection;
stat.text = "SELECT * FROM " + tableTree.selectedItem.@databaseName + "." + tableTree.selectedItem.@label;
lastStatement(stat.text);
stat.execute(-1, new Responder(tableSuccess, tableError));
}
function tableSuccess(evt:SQLResult):void {
if (evt.data != null) {
for (var item:Object in evt.data) {
var obj:Object = new Object();
for (var value:Object in evt.data[item]) {
obj["db_"+value] = evt.data[item][value];
}
tableData.addItem(obj);
}
}
}
function tableError(evt:SQLError):void {
Alert.show("Unable to read table data.", "Error");
}
}

private function newTable():void {
PopUpManager.addPopUp(newTableWindow, this);
PopUpManager.centerPopUp(newTableWindow);
newTableWindow.title = "Create new table";
focusManager.setFocus(newTableName);
}

private function dropTable():void {
Alert.show("Are you sure you want to completely delete this table?", "Drop table?", Alert.YES | Alert.NO, null, dropConfirm);
function dropConfirm(evt:CloseEvent):void {
if (evt.detail == Alert.YES) {
var stat:SQLStatement = new SQLStatement();
stat.sqlConnection = connection;
stat.text = "DROP TABLE " + selectedDatabase + "." + tableTree.selectedItem.@label;
lastStatement(stat.text);
stat.execute( -1, new Responder(dropTableSuccess, dropTableError));
}
}
function dropTableSuccess(evt:SQLResult):void {
loadDataSchema(selectedDatabase);
}
function dropTableError(evt:SQLError):void {
Alert.show("ERROR:" + evt.details, "Error");
}
}

private function closeNewTableWindow():void{
PopUpManager.removePopUp(newTableWindow);
}

private function createNewTable():void {
var stat:SQLStatement = new SQLStatement();
stat.sqlConnection = connection;
stat.text = "CREATE TABLE IF NOT EXISTS " + selectedDatabase + "." + newTableName.text + "(id INTEGER PRIMARY KEY AUTOINCREMENT, blankColumn TEXT)";
lastStatement(stat.text);
stat.execute( -1, new Responder(newTableSuccess, newTableError));
function newTableSuccess(evt:SQLResult):void {
closeNewTableWindow();
loadDataSchema(selectedDatabase);
}
function newTableError(evt:SQLError):void {
Alert.show("ERROR:" + evt.details, "Error");
}
}

private function lastStatement(text:String):void {
statementText.text = text;
sqlHistory.push(text);
}

private function openHistory():void {
PopUpManager.addPopUp(historyWindow, this);
historyWindow.width = width - 100;
historyWindow.height = height - 100;
PopUpManager.centerPopUp(historyWindow);
historyText.text = "";
for (var i:int = sqlHistory.length - 1; i >= 0; i--) {
historyText.appendText(sqlHistory[i] + "\n");
}
}

private function closeHistoryWindow():void {
PopUpManager.removePopUp(historyWindow);
}

private function saveTable():void {
var keyColumnName:String = tableTree.selectedItem.@primaryKeyColumn;
// clear all "sel" and store them in a temp array
var tempSel:Array = [];
for (var s:int = 0; s < tableData.length; s++) {
if (tableData[s].sel) {
tempSel.push(true);
tableData[s].sel = false;
}else
if (!tableData[s].sel) {
tempSel.push(false);
}
}
// update each row
for (var i:int = 0; i < tableData.length; i++) {
var stat:SQLStatement = new SQLStatement();
var sqlStat:String = "UPDATE " + selectedDatabase + "." + tableTree.selectedItem.@label + " SET";
// add each attribute as parameter
for (var attribute:String in tableData[i]) {
// if column is not our CheckBox column or the key column
if (attribute != "mx_internal_uid" && attribute!=keyColumnName && attribute!="sel") {
// add value as parameter
stat.parameters["@" + attribute.substr(3)] = tableData[i][attribute];
sqlStat += " " + attribute.substr(3) + "=@" + attribute.substr(3) + ",";
}
}
// remove the last comma
sqlStat = sqlStat.substr(0, sqlStat.length - 1);
sqlStat += " WHERE " + keyColumnName + "=" + tableData[i]["db_"+keyColumnName];
stat.sqlConnection = connection;
stat.text = sqlStat;
lastStatement(stat.text);
stat.execute( -1, new Responder(saveSuccess, saveError));
}

function saveSuccess(evt:SQLResult):void {
}

function saveError(evt:SQLError):void {
Alert.show("ERROR: " + evt.details, "Error");
}

tableSelect();
for (var t:int = 0; t < tableData.length; t++) {
if (tempSel[t]) tableData[t].sel=true;
}
tableGrid.invalidateDisplayList();
tableGrid.invalidateList();
}

private function deleteSelected():void {
var keyColumnName:String = tableTree.selectedItem.@primaryKeyColumn;
for (var i:int = 0; i < tableData.length; i++) {
if (tableData[i].sel) {
var stat:SQLStatement = new SQLStatement();
stat.sqlConnection = connection;
stat.text = "DELETE FROM " + selectedDatabase + "." + tableTree.selectedItem.@label + " WHERE " + keyColumnName + "=" + tableData[i]["db_" + keyColumnName];
lastStatement(stat.text);
stat.execute( -1, new Responder(deleteSuccess, deleteError));
}
}
tableSelect();
tableGrid.invalidateDisplayList();
tableGrid.invalidateList();

function deleteSuccess(evt:SQLResult):void {
}
function deleteError(evt:SQLError):void {
Alert.show("ERROR: " + evt.details, "Error");
}
}

private function newRecord():void {
var stat:SQLStatement = new SQLStatement();
stat.sqlConnection = connection;
stat.text = "INSERT INTO " + selectedDatabase + "." + tableTree.selectedItem.@label + " DEFAULT VALUES;";
lastStatement(stat.text);
stat.execute( -1, new Responder(newSuccess, newError));

function newSuccess(evt:SQLResult):void {
tableSelect();
tableGrid.invalidateDisplayList();
tableGrid.invalidateList();
}
function newError(evt:SQLError):void {
Alert.show("ERROR: " + evt.details, "Error");
}
}

private function columnSelect():void {
connection.loadSchema(SQLTableSchema, tableTree.selectedItem.@label, tableTree.selectedItem.@databaseName);
var schema:SQLSchemaResult = connection.getSchemaResult();
var fullSQL:String = schema.tables[0].sql;
// extract the text inside the ( )
fullSQL = fullSQL.substring( fullSQL.indexOf("(") + 1 , fullSQL.lastIndexOf(")") );
// split all columns into an array
var columns:Array = fullSQL.split(",");
// get the currently selected column
var currentColumn:String = columns[columnList.selectedIndex];
// delete the name of the column from this text
var currentParameters:String = currentColumn.substr(currentColumn.indexOf(columnList.selectedItem.name) + columnList.selectedItem.name.length + 1);
// find DEFAULT and extract it
var defaultMatch:String = "";
var defaultPattern:RegExp = /((DEFAULT)\s((".+")|([0-9]+)))/i;
if (currentParameters.match(defaultPattern)) {
defaultMatch = currentParameters.match(defaultPattern)[0];
// delete it from currentParameters
currentParameters = currentParameters.replace(defaultMatch, "");
// delete "DEFAULT" from the match
defaultMatch = defaultMatch.substr(8);
// if any quotes are found, remove the first and last symbols
if (defaultMatch.indexOf('"') != -1) {
defaultMatch = defaultMatch.substring(1, defaultMatch.length - 1);
}
}
// find ON CONFLICT and extract it
var conflictMatch:String = "";
var conflictPattern:RegExp = /((ON CONFLICT)\s(ABORT|FAIL|IGNORE|ROLLBACK|REPLACE))/i;
if (currentParameters.match(conflictPattern)) {
conflictMatch = currentParameters.match(conflictPattern)[0];
// delete it from currentParameters
currentParameters = currentParameters.replace(conflictMatch, "");
// delete "ON CONFLICT" from the match
conflictMatch = conflictMatch.substr(12);
}
// apply values
col_name.text = columnList.selectedItem.name;
col_key.selected = (currentParameters.toUpperCase().indexOf("PRIMARY KEY") != -1)?(true):(false);
col_auto.selected = (currentParameters.toUpperCase().indexOf("AUTOINCREMENT") != -1)?(true):(false);
col_unique.selected = (currentParameters.toUpperCase().lastIndexOf("UNIQUE") != -1)?(true):(false);
col_null.selected = (currentParameters.toUpperCase().indexOf("NOT NULL") != -1)?(false):(true);
col_default.text = defaultMatch;
col_conflict.selectedIndex = 0;
if (conflictMatch.toUpperCase() == "ABORT") col_conflict.selectedIndex = 1;
if (conflictMatch.toUpperCase() == "FAIL") col_conflict.selectedIndex = 2;
if (conflictMatch.toUpperCase() == "IGNORE") col_conflict.selectedIndex = 3;
if (conflictMatch.toUpperCase() == "ROLLBACK") col_conflict.selectedIndex = 4;
if (conflictMatch.toUpperCase() == "REPLACE") col_conflict.selectedIndex = 5;

// read data type
col_data.textInput.text = schema.tables[0].columns[columnList.selectedIndex].dataType;

// enable or disable ON CONFLICT
checkConflict();
// unhighlight "Update selected"
col_b_update.emphasized = false;
}

private function checkConflict():void {
if (col_key.selected || !col_null.selected || col_unique.selected) {
col_conflict.enabled = true;
}else {
col_conflict.enabled = false;
}
}

private function formChange():void {
checkConflict();
if (columnList.selectedItems.length > 0) {
col_b_update.emphasized = true;
}
}

private function addColumn():void {
col_b_update.emphasized = false;
var prevTableName:String = tableTree.selectedItem.@label;
if (col_name.text != "" && col_data.textInput.text != "" && (col_null.selected || col_default.text != "")) {
connection.loadSchema(SQLTableSchema, tableTree.selectedItem.@label, tableTree.selectedItem.@databaseName);
var schema:SQLSchemaResult = connection.getSchemaResult();
var fullSQL:String = schema.tables[0].sql;
// extract the text inside the ( )
fullSQL = fullSQL.substring( fullSQL.indexOf("(") + 1 , fullSQL.lastIndexOf(")") );
var sqlText:String = "CREATE TABLE " + selectedDatabase + "." + tableTree.selectedItem.@label + " (";
sqlText += fullSQL + ", ";
// add the new column
sqlText += col_name.text + " " + col_data.textInput.text + " ";
if (col_key.selected) sqlText += "PRIMARY KEY ";
if (col_key.selected && col_conflict.selectedIndex > 0) sqlText += "ON CONFLICT " + col_conflict.selectedLabel + " ";
if (col_key.selected && col_auto.selected) sqlText += "AUTOINCREMENT ";
if (!col_null.selected) sqlText += "NOT NULL ";
if (!col_null.selected && col_conflict.selectedIndex > 0) sqlText += "ON CONFLICT " + col_conflict.selectedLabel + " ";
if (col_unique.selected) sqlText += "UNIQUE ";
if (col_unique.selected && col_conflict.selectedIndex > 0) sqlText += "ON CONFLICT " + col_conflict.selectedLabel + " ";
if (col_default.text != "") {
sqlText += "DEFAULT ";
if (isNaN(Number(col_default.text))) sqlText += '"' + col_default.text + '"';
if (!isNaN(Number(col_default.text))) sqlText += col_default.text;
}
sqlText += ");";
lastStatement(sqlText);

// Create backup
var backupName:String = "backup";
while (!tableIsUnique(backupName)) {
backupName += "0";
}
var bstat:SQLStatement = new SQLStatement();
bstat.sqlConnection = connection;
bstat.text = "CREATE TABLE " + selectedDatabase + "." + backupName + " (" + fullSQL + ");";
bstat.execute();

// Copy data to backup
var cstat:SQLStatement = new SQLStatement();
cstat.sqlConnection = connection;
cstat.text = "INSERT INTO " + selectedDatabase + "." + backupName + " SELECT * FROM " + selectedDatabase + "." + tableTree.selectedItem.@label;
cstat.execute();

// Delete initial table
var dstat:SQLStatement = new SQLStatement();
dstat.sqlConnection = connection;
dstat.text = "DROP TABLE " + selectedDatabase + "." + tableTree.selectedItem.@label;
dstat.execute();

// Create new table
var stat:SQLStatement = new SQLStatement();
stat.sqlConnection = connection;
stat.text = sqlText;
stat.execute( -1, new Responder(newColumnSuccess, newColumnError));
}else {
Alert.show("Please fill all the required fields!", "Error");
}
function newColumnSuccess(evt:SQLResult):void {
// Insert previous values
var istat:SQLStatement = new SQLStatement();
istat.sqlConnection = connection;
istat.text = "INSERT INTO " + selectedDatabase + "." + prevTableName + " (" + columnNames() + ") SELECT " + columnNames() + " FROM " + selectedDatabase + "." + backupName;
istat.execute();
// Delete backup
var bdstat:SQLStatement = new SQLStatement();
bdstat.sqlConnection = connection;
bdstat.text = "DROP TABLE " + selectedDatabase + "." + backupName;
bdstat.execute();
tableSelect();
}
function newColumnError(evt:SQLError):void {
Alert.show("ERROR: " + evt.details + "\n\nRestoring the database using backup...", "Error");
// Restore table
var rstat:SQLStatement = new SQLStatement();
rstat.sqlConnection = connection;
rstat.text = "ALTER TABLE " + selectedDatabase + "." + backupName + " RENAME TO " + prevTableName
rstat.execute();
tableSelect();
}
}

private function deleteColumn():void {
col_b_update.emphasized = false;
var prevTableName:String = tableTree.selectedItem.@label;

connection.loadSchema(SQLTableSchema, tableTree.selectedItem.@label, tableTree.selectedItem.@databaseName);
var schema:SQLSchemaResult = connection.getSchemaResult();
var fullSQL:String = schema.tables[0].sql;
// extract the text inside the ( )
fullSQL = fullSQL.substring( fullSQL.indexOf("(") + 1 , fullSQL.lastIndexOf(")") );
// split all columns into an array
var columns:Array = fullSQL.split(",");
// get the currently selected index
var currentIndex:int = columnList.selectedIndex;

// Create backup
var backupName:String = "backup";
while (!tableIsUnique(backupName)) {
backupName += "0";
}
var bstat:SQLStatement = new SQLStatement();
bstat.sqlConnection = connection;
var sqlText:String = "CREATE TABLE " + selectedDatabase + "." + backupName + " (";
columns.splice(currentIndex, 1);
if (columns.length == 0) {
Alert.show("Can't make a table completely empty! Leave at least one column.", "Nope");
return;
}
sqlText += String(columns);
sqlText += ");";
bstat.text = sqlText;
lastStatement(sqlText);
bstat.execute();

// Copy data to backup
var cstat:SQLStatement = new SQLStatement();
cstat.sqlConnection = connection;
cstat.text = "INSERT INTO " + selectedDatabase + "." + backupName + " (" + columnNames(currentIndex) + ") SELECT " + columnNames(currentIndex) + " FROM " + selectedDatabase + "." + tableTree.selectedItem.@label;
cstat.execute();

// Drop existing table
var dstat:SQLStatement = new SQLStatement();
dstat.sqlConnection = connection;
dstat.text = "DROP TABLE " + selectedDatabase + "." + tableTree.selectedItem.@label;
dstat.execute();

// Rename backup table to initial name
var rstat:SQLStatement = new SQLStatement();
rstat.sqlConnection = connection;
rstat.text = "ALTER TABLE " + selectedDatabase + "." + backupName + " RENAME TO " + prevTableName
rstat.execute();
tableSelect();
}

private function tableIsUnique(name:String):Boolean {
var r:Boolean = true;
for (var i:int = 0; i < dbData..tb.length(); i++) {
if (dbData..tb[i].@label == name) {
r = false;
break;
}
}
return r;
}

private function columnNames(exception:int = -1):String {
var r:String = "";
var array:Array = [];
for (var i:int = 0; i < columnData.length; i++) {
if (i != exception) array.push(columnData[i].name);
}
r = String(array);
return r;
}
]]>
</fx:Script>

<s:HGroup gap="0" width="100%" height="100%">
<s:VGroup width="200" height="100%" gap="0">
<s:HGroup>
<s:Button label="New table" click="newTable();" enabled="{tableTree.selectedItems.length>0}"/>
<s:Button label="Drop table" click="dropTable();" enabled="{isTableSelected}" />
</s:HGroup>
<mx:Tree id="tableTree" width="100%" height="100%" dataProvider="{dbData}" showRoot="false" labelField="@label" itemClick="tableSelect();"/>
</s:VGroup>
<s:VGroup width="100%" height="100%" gap="0">
<mx:Box height="80" width="100%">
<s:VGroup paddingTop="10" paddingLeft="10" paddingRight="10" paddingBottom="10" width="100%" height="100%">
<s:HGroup width="100%" verticalAlign="middle">
<s:Label width="100%">Latest SQL statement:</s:Label>
<s:Button width="100" label="View history" click="openHistory();" />
</s:HGroup>
<s:TextArea id="statementText" editable="false" width="100%" height="30"/>
</s:VGroup>
</mx:Box>
<mx:TabNavigator width="100%" height="100%" paddingTop="0">
<s:NavigatorContent label="Table contents">
<s:VGroup width="100%" height="100%" gap="0">
<mx:HBox width="100%" height="30" paddingLeft="8" paddingTop="6">
<mx:CheckBox label="Select all" change="selectAllChange(event);" />
<s:Button label="Delete selected" enabled="{isTableSelected}" click="deleteSelected();" />
<s:Button id="saveTableButton" label="Save changes" click="saveTable();" enabled="{isTableSelected}"/>
<s:Button id="newRecordButton" label="Add a record" click="newRecord();" enabled="{isTableSelected}"/>
</mx:HBox>
<mx:AdvancedDataGrid id="tableGrid" width="100%" height="100%" dataProvider="{tableData}" editable="true" itemEditBegin="saveTableButton.emphasized=true;">
<mx:columns>
<mx:AdvancedDataGridColumn dataField="" headerText="Data" editable="false" />
</mx:columns>
</mx:AdvancedDataGrid>
</s:VGroup>
</s:NavigatorContent>
<s:NavigatorContent label="Edit columns">
<s:HGroup width="100%" height="100%" >
<mx:List id="columnList" width="200" height="100%" dataProvider="{columnData}" labelField="name" change="columnSelect();" />
<s:VGroup height="100%" paddingTop="10">
<s:HGroup>
<s:Button id="col_b_add" label="Add column" enabled="{isTableSelected}" click="addColumn();" />
<s:Button id="col_b_update" label="Update selected" enabled="{columnList.selectedItems.length > 0}" />
<s:Button id="col_b_delete" label="Delete selected" enabled="{columnList.selectedItems.length > 0}" click="deleteColumn();" />
</s:HGroup>
<mx:Form enabled="{isTableSelected}">
<mx:FormItem label="Name" required="true">
<s:TextInput id="col_name" change="formChange();"/>
</mx:FormItem>
<mx:FormItem label="Data type" required="true">
<s:ComboBox id="col_data" dataProvider="{dataTypes}" change="formChange();"/>
</mx:FormItem>
<mx:FormItem label="Primary Key">
<s:CheckBox id="col_key" change="formChange();" />
</mx:FormItem>
<mx:FormItem label="AutoIncrement">
<s:CheckBox id="col_auto" change="formChange();" enabled="{col_key.selected}" />
</mx:FormItem>
<mx:FormItem label="Unique">
<s:CheckBox id="col_unique" change="formChange();" />
</mx:FormItem>
<mx:FormItem label="Allow Null">
<s:CheckBox id="col_null" change="formChange();" selected="true" />
</mx:FormItem>
<mx:FormItem label="Default Value" required="{!col_null.selected}">
<s:TextArea id="col_default" change="formChange();"/>
</mx:FormItem>
<mx:FormItem label="On Conflict">
<mx:ComboBox id="col_conflict" dataProvider="{conflictTypes}" editable="false" change="formChange();"/>
</mx:FormItem>
</mx:Form>
</s:VGroup>
</s:HGroup>
</s:NavigatorContent>
<s:NavigatorContent label="Query">

</s:NavigatorContent>
</mx:TabNavigator>
</s:VGroup>
</s:HGroup>

</s:WindowedApplication>

Thanks for reading!

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