Implement methods to add columns and create new tables onUpgrade

src/com/michaldabski/msqlite/DataTypes.java

@@ -5,6 +5,7 @@ public class DataTypes
 {	
 	// Class field types
 	public final static int
+		TYPE_NA = -1,
 		TYPE_OTHER = 100,
 		TYPE_STRING = 101,
 		TYPE_COLLECTION = 102,

src/com/michaldabski/msqlite/MSQLiteOpenHelper.java

@@ -2,10 +2,8 @@
 
 import java.util.ArrayList;
 import java.util.Collection;
-import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
-import java.util.Map;
 
 import android.annotation.TargetApi;
 import android.content.ContentValues;
@@ -16,7 +14,6 @@
 import android.database.sqlite.SQLiteDatabase.CursorFactory;
 import android.database.sqlite.SQLiteOpenHelper;
 import android.os.Build;
-import android.text.TextUtils;
 import android.util.Log;
 
 import com.michaldabski.msqlite.models.Table;
@@ -46,30 +43,32 @@ public MSQLiteOpenHelper(Context context, String name, CursorFactory factory,
 	// Static methods
 	public static void createTable(SQLiteDatabase database, Class<?> type, boolean ifNotExist)
 	{
-		database
-			.execSQL(new CreateTable(type).setIF_NOT_EXIST(ifNotExist).build());
+		createTable(database, new Table(type), ifNotExist);
 	}
 
-	private static Map<String, String> getCreateTableStatements(SQLiteDatabase database)
+	public static void createTable(SQLiteDatabase database, Table table, boolean ifNotExist)
 	{
-		final int COLUMN_NAME = 0,
-				COLUMN_SQL = 1;
-		Cursor c = database.rawQuery("SELECT name, sql FROM SQLITE_MASTER WHERE type=?", new String [] {"table"});
-		Map<String,String> result = new HashMap<String, String>(c.getCount());
-		while (c.moveToNext())
-		{
-			result.put(c.getString(COLUMN_NAME), c.getString(COLUMN_SQL));
-		}
-		c.close();
-		return result;
+		database
+			.execSQL(new CreateTable(table).setIF_NOT_EXIST(ifNotExist).build());
 	}
 
 	private static void upgradeTable(SQLiteDatabase database, Table table)
 	{
-		Cursor cur = database.rawQuery("PRAGMA table_info("+table.getName()+");", null);
-		// TODO: Compare columns
-		// [cid, name, type, notnull, dflt_value, pk]
-		Log.i(table.getName(), "table upgraded");
+		Cursor cursor = database.rawQuery("PRAGMA table_info("+table.getName()+");", null);
+		if (cursor.getCount() == 0)
+		{
+			createTable(database, table, false);
+			Log.i("DatabaseUpgrade", "table created: "+table.getName());
+		}
+		else
+		{
+			Table currentDatabaseTable = Table.fromCursor(table.getName(), cursor);
+			for (String sql : Table.upgradeTable(currentDatabaseTable, table))
+			{
+				database.execSQL(sql);
+				Log.i("DatabaseUpgrade", "table altered. Query: "+sql);
+			}
+		}
 	}
 
 	public void upgradeDatabase()
@@ -125,23 +124,7 @@ public void onCreate(SQLiteDatabase db)
 	@Override
 	public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion)
 	{
-		for (Class<?> c : classes)
-		{
-			dropTable(db, c, true);
-			createTable(db, c, false);
-		}
-		// TODO detect differences between tables and modify table instead of re-creating
-	}
-
-	@Override
-	public void onDowngrade(SQLiteDatabase db, int oldVersion, int newVersion)
-	{
-		for (Class<?> c : classes)
-		{
-			dropTable(db, c, true);
-			createTable(db, c, false);
-		}
-		// TODO detect differences between tables and modify table instead of re-creating
+		upgradeDatabase(db);
 	}
 
 	/**

src/com/michaldabski/msqlite/models/Column.java

@@ -1,10 +1,8 @@
 package com.michaldabski.msqlite.models;
 
-import java.io.NotSerializableException;
-import java.io.Serializable;
 import java.lang.reflect.Field;
-import java.util.Locale;
 
+import android.database.Cursor;
 import android.util.Log;
 
 import com.michaldabski.msqlite.Annotations.ColumnName;
@@ -30,25 +28,48 @@ public class Column
 		dataType,
 		// table.field
 		uniqueName;
-
-	protected final Class<?> fieldClass;
 	private final int fieldType;
 
-	public Column(Field field)
+	public static Column fromCursor(Cursor cursor, Table table)
+	{
+		final int FIELD_NAME = 1,
+				FIELD_TYPE = 2,
+				FIELD_NOT_NULL = 3,
+				FIELD_DEF_VALUE = 4,
+				FIELD_PK = 5;
+		String name = cursor.getString(FIELD_NAME);
+		Column column = new Column(null, cursor.getInt(FIELD_NOT_NULL)==1, cursor.getInt(FIELD_PK)==1, name, 
+				cursor.getString(FIELD_TYPE), table.getName()+"."+name, DataTypes.TYPE_NA);
+
+		return column;
+	}
+
+	private Column(Field field, boolean nOT_NULL, boolean pRIMARY_KEY,
+			String name, String dataType, String uniqueName,
+			int fieldType)
+	{
+		this.field = field;
+		NOT_NULL = nOT_NULL;
+		PRIMARY_KEY = pRIMARY_KEY;
+		this.name = name;
+		this.dataType = dataType;
+		this.uniqueName = uniqueName;
+		this.fieldType = fieldType;
+	}
+
+	public Column(Field field, Table table)
 	{
 		this.field =field;
 
 		if (field.isAnnotationPresent(ColumnName.class)) this.name = field.getAnnotation(ColumnName.class).value();
 		else this.name = field.getName();
 
-		this.fieldClass = field.getType();
-
-		this.uniqueName = String.format("%s.%s", field.getDeclaringClass().getSimpleName(), name);
+		this.uniqueName = String.format("%s.%s", table.getName(), name);
 
-		fieldType = DataTypes.getFieldType(fieldClass);
+		fieldType = DataTypes.getFieldType(field.getType());
 		if (fieldType == DataTypes.TYPE_OTHER)
 		{
-			Log.w("MSQLite", fieldClass.getSimpleName()+" is not supported as a table field yet. Consider making this field transient.");
+			Log.w("MSQLite", field.getType().getSimpleName()+" is not supported as a table field yet. Consider making this field transient.");
 			dataType = null;
 			return;
 		}
@@ -171,6 +192,11 @@ public int getFieldType()
 		return fieldType;
 	}
 
+	public boolean isPRIMARY_KEY()
+	{
+		return PRIMARY_KEY;
+	}
+
 	public void setValueFromString(Object object, String value) throws IllegalArgumentException
 	{
 		try

src/com/michaldabski/msqlite/models/Table.java

@@ -29,6 +29,59 @@ public class Table
 	protected final List<Column> columns;
 	protected final List<Column> primaryKeys;
 
+	/**
+	 * Create table instance from cursor
+	 * @param cursor PRAGMA table_info(TABLE_NAME);
+	 * @return table model based on data from the cursor
+	 */
+	public static Table fromCursor(String tableName, Cursor cursor)
+	{
+		Table result = new Table(tableName, new ArrayList<Column>(cursor.getCount()));
+		while (cursor.moveToNext())
+		{
+			Column column = Column.fromCursor(cursor, result);
+			result.columns.add(column);
+			if (column.isPRIMARY_KEY())
+				result.primaryKeys.add(column);
+		}
+		return result;
+	}
+
+	/**
+	 *	Create upgrade statements according to sqlite rules:
+	 *	http://www.sqlite.org/lang_altertable.html
+	 * 	only new columns are added.
+	 *	@return alter statements to alter upgradeFrom table into this table
+	 */
+	public List<String> upgradeTable(Table upgradeFrom)
+	{
+		List<String> result = new ArrayList<String>();
+
+		// add new columns
+		for (Column column : columns)
+		{
+			if (upgradeFrom.columns.contains(column) == false)
+			{
+				StringBuilder resultBuilder = new StringBuilder("Alter table `").append(this.name)
+						.append("` ADD COLUMN ").append(column.getBuilder()).append(';');
+				result.add(resultBuilder.toString());
+			}
+		}
+		return result;
+	}
+
+	public static List<String> upgradeTable(Table currentTable, Table newTable)
+	{
+		return newTable.upgradeTable(currentTable);
+	}
+
+	private Table(String name, List<Column> columns)
+	{
+		this.name = name;
+		this.columns = columns;
+		this.primaryKeys = new ArrayList<Column>(1);
+	}
+
 	/**
 	 * Create Table from java class definition
 	 * 
@@ -57,7 +110,7 @@ public Table(Class<?> type)
 		for (Field field : fields)
 		{
 			if ((field.getModifiers() & (Modifier.TRANSIENT | Modifier.STATIC | Modifier.FINAL)) > 0) continue;
-			Column column = new Column(field);
+			Column column = new Column(field, this);
 			if (column.getDataType() == null) continue;
 			columns.add(column);
 			if (column.PRIMARY_KEY) primaryKeys.add(column);

src/com/michaldabski/msqlite/queries/CreateTable.java

@@ -11,11 +11,16 @@ public class CreateTable extends QueryBuilder
 {
 	private boolean 
 		IF_NOT_EXISTS = false;
-	
+
 	public CreateTable(Class<?> type)
 	{
 		super(type);
 	}
+
+	public CreateTable(Table table)
+	{
+		super(table);
+	}
 
 	public CreateTable setIF_NOT_EXIST(boolean iF_NOT_EXIST)
 	{

src/com/michaldabski/msqlite/queries/QueryBuilder.java

@@ -5,17 +5,23 @@
 
 public abstract class QueryBuilder
 {
-	protected Class<?> type;
+	protected Table table;
 	protected String condition = "1";	
 
+	@Deprecated
 	public QueryBuilder(Class<?> type)
 	{
-		this.type = type;
+		this.table = new Table(type);
+	}
+
+	public QueryBuilder(Table table)
+	{
+		this.table = table;
 	}
 
 	public Table getTable()
 	{
-		return new Table(type);
+		return table;
 	}
 
 //	public abstract <T> Result<T> execute(Class<T> type);