Example: Move the SQL statements

Moving the SQL statements into separate variables
outside the scope of the 'init_db' function, improves
readability.

Change-Id: I716dfceef6dc343287afab17f74e8de7fae618c6
Reviewed-by: Cristian Maureira-Fredes <cristian.maureira-fredes@qt.io>
Reviewed-by: Paul Wicking <paul.wicking@qt.io>
Reviewed-by: Christian Tismer <tismer@stackless.com>
 

3 files changed, 61 insertions, 57 deletions

diff --git a/examples/sql/books/bookwindow.py b/examples/sql/books/bookwindow.py
index 500acf2ef..c6d43b1f3 100644
--- a/examples/sql/books/bookwindow.py
+++ b/examples/sql/books/bookwindow.py
@@ -58,11 +58,8 @@ class BookWindow(QMainWindow, Ui_BookWindow):
         QMainWindow.__init__(self)
         self.setupUi(self)
 
-        #check for SQL errors
-        err = createdb.init_db()
-        if err.type() is not QSqlError.NoError:
-            showError(err)
-            return
+        #Initialize db
+        createdb.init_db()
 
         model = QSqlRelationalTableModel(self.bookTable)
         model.setEditStrategy(QSqlTableModel.OnManualSubmit)
diff --git a/examples/sql/books/createdb.py b/examples/sql/books/createdb.py
index d662cacd1..1ca52470f 100644
--- a/examples/sql/books/createdb.py
+++ b/examples/sql/books/createdb.py
@@ -63,43 +63,59 @@ def add_author(q, name, birthdate):
     q.exec_()
     return q.lastInsertId()
 
+BOOKS_SQL = """
+    create table books(id integer primary key, title varchar, author integer,
+                       genre integer, year integer, rating integer)
+    """
+AUTHORS_SQL = """
+    create table authors(id integer primary key, name varchar, birthdate date)
+    """
+GENRES_SQL = """
+    create table genres(id integer primary key, name varchar)
+    """
+INSERT_AUTHOR_SQL = """
+    insert into authors(name, birthdate) values(?, ?)
+    """
+INSERT_GENRE_SQL = """
+    insert into genres(name) values(?)
+    """
+INSERT_BOOK_SQL = """
+    insert into books(title, year, author, genre, rating)
+                values(?, ?, ?, ?, ?)
+    """
 
 def init_db():
+    """
+    init_db()
+    Initializes the database.
+    If tables "books" and "authors" are already in the database, do nothing.
+    Return value: None or raises ValueError
+    The error value is the QtSql error instance.
+    """
+    def check(func, *args):
+        if not func(*args):
+            raise ValueError(func.__self__.lastError())
     db = QSqlDatabase.addDatabase("QSQLITE")
     db.setDatabaseName(":memory:")
 
-    if not db.open():
-        return db.lastError()
-
-    tables = db.tables()
-    for table in tables:
-        if table == "books" and table == "authors":
-            return QSqlError()
+    check(db.open)
 
     q = QSqlQuery()
-    if not q.exec_("create table books(id integer primary key, title varchar, author integer, "
-            "genre integer, year integer, rating integer)"):
-        return q.lastError()
-    if not q.exec_("create table authors(id integer primary key, name varchar, birthdate date)"):
-        return q.lastError()
-    if not q.exec_("create table genres(id integer primary key, name varchar)"):
-        return q.lastError()
+    check(q.exec_,BOOKS_SQL)
+    check(q.exec_,AUTHORS_SQL)
+    check(q.exec_,GENRES_SQL)
+    check(q.prepare,INSERT_AUTHOR_SQL)
 
-    if not q.prepare("insert into authors(name, birthdate) values(?, ?)"):
-        return q.lastError()
     asimovId = add_author(q, "Isaac Asimov", datetime(1920, 2, 1))
     greeneId = add_author(q, "Graham Greene", datetime(1904, 10, 2))
     pratchettId = add_author(q, "Terry Pratchett", datetime(1948, 4, 28))
 
-    if not q.prepare("insert into genres(name) values(?)"):
-        return q.lastError()
+    check(q.prepare,INSERT_GENRE_SQL)
     sfiction = add_genre(q, "Science Fiction")
     fiction = add_genre(q, "Fiction")
     fantasy = add_genre(q, "Fantasy")
 
-    if not q.prepare("insert into books(title, year, author, genre, rating) "
-            "values(?, ?, ?, ?, ?)"):
-        return q.lastError()
+    check(q.prepare,INSERT_BOOK_SQL)
     add_book(q, "Foundation", 1951, asimovId, sfiction, 3)
     add_book(q, "Foundation and Empire", 1952, asimovId, sfiction, 4)
     add_book(q, "Second Foundation", 1953, asimovId, sfiction, 3)
@@ -113,5 +129,3 @@ def init_db():
     add_book(q, "Guards! Guards!", 1989, pratchettId, fantasy, 3)
     add_book(q, "Night Watch", 2002, pratchettId, fantasy, 3)
     add_book(q, "Going Postal", 2004, pratchettId, fantasy, 3)
-
-    return QSqlError()
diff --git a/sources/pyside2/doc/deployment.rst b/sources/pyside2/doc/deployment.rst
index a125dc4d7..eb8d77b0d 100644
--- a/sources/pyside2/doc/deployment.rst
+++ b/sources/pyside2/doc/deployment.rst
@@ -6,23 +6,23 @@ Deploying or freezing an application is a crucial part of many Python projects.
 Most large projects are not based on a single Python file, so
 the distribution of these applications becomes more difficult.
 
-The options for a project are:
+Here are a few distribution options that you could use:
  1. Sending a normal zip-file with the application's content.
  2. Building a proper `Python package (wheel) <https://packaging.python.org/>`_.
- 3. Freezing the application in a single binary file, or into a directory.
+ 3. Freezing the application into a single binary file or a directory.
 
-For the **third** option, there are many available tools:
+If you choose the **third** option, consider using one of these tools:
  * `fbs <https://build-system.fman.io/>`_,
  * `PyInstaller <https://www.pyinstaller.org/>`_,
  * `cx_Freeze <https://anthony-tuininga.github.io/cx_Freeze/>`_,
  * `py2exe <http://www.py2exe.org/>`_,
  * `py2app <https://py2app.readthedocs.io/en/latest/>`_,
 
-Since |project| is a cross-platform framework,
-we would like to focus on solutions that at least work on
-the three major platform supported by Qt: Linux, macOS, and Windows.
-
-The following table summarizes the above mentioned tools support:
+|project| is a cross-platform framework,
+so we would like to focus on solutions that work on the three
+major platforms supported by Qt: Linux, macOS, and Windows.
+The following table summarizes the platform support for those packaging
+tools:
 
 ===========   =======   =====   =====   =======
 Name          License   Linux   macOS   Windows
@@ -34,34 +34,27 @@ py2exe        MIT       no      no      yes
 py2app        MIT       no      yes     no
 ===========   =======   =====   =====   =======
 
-From the table we can see that only *fbs*, *cx_Freeze* and *PyInstaller*
-meet our requirements.
+According to this table, only *fbs*, *cx_Freeze*, and *PyInstaller*
+meets our cross-platform requirement.
 
-All tools are command-line based, and it could become
-a hard task to include more resources to your application, such as
-images, icons, and meta-information, because you will need to create
-special hooks or separate scripts to handle them.
-Additionally, since this only
-allows you to freeze your current application, you don't have
-any mechanism to update your application.
+As these are command-line tools, it could be hard to include
+resources to your application, such as images, icons, and
+meta-information. This means, you will need special hooks
+or scripts to handle them before adding to the package.
+In addition to this, these tools does not offer a mechanism
+to update your application packages.
 
-To cover the update part, there is a tool built around PyInstaller
-called `PyUpdater <https://www.pyupdater.org/>`_ which enables
-a simple mechanism to ship applications updates.
+To create update packages, use the `PyUpdater <https://www.pyupdater.org/>`_,
+which is built around PyInstaller.
 
-On top of all these features, including also a nice interface
-that allows the user to install the application step by step,
-or even better, provide templates to create new projects to easily
-freeze-them-up is something really beneficial for both developers
-and end-users.
-This is where `fbs <https://build-system.fman.io>`_ enters the
-game, being based on PyInstaller, but including all the nice features
-we previously mentioned.
+The `fbs <https://build-system.fman.io>`_ tool offers a nice UI
+that allows the user to install the application step-by-step.
 
 Here you can find a set of tutorials on how to use the previously
 described tools.
 
-.. note:: Deployment is possible only in Qt for Python 5.12.2
+.. note:: Deployment is supported only from Qt for Python 5.12.2 and
+later.
 
 .. toctree::
     :name: mastertoc