PyQt连接到Postgresql并显示值

Question

我是Python和PyQt的新手。我想知道如何使用PyQt连接到Postgresql，并将其显示在网格窗口中。我在用Qt设计师。有人能帮我吗？谢谢。

向你问好，尼森

Answer 1

PyQt有数据库支持(我个人没有使用它，所以我不能评论)，但是如果您查看QDatabase，应该是非常简单的文档。如果应用程序的api总是可以访问Qt，那么这可能是最好的方法，因为它们还有一些映射到接口的附加模型。

另一种选择是使用Python (对象关系映射器)，例如Django、SQLAlchemy或storm，并定义表的(模型)，并将它们手动加载到设计器接口中。

我个人的做法是，我实际上已经构建了自己的ORM ORB和一个名为PyQt的扩展库ProjexUI。ORB库与Qt无关，因此可以在非Qt项目中使用，ProjexUI库包含有助于在Qt小部件中使用数据库记录的映射。

有关文档和更多信息，请参阅：http://www.projexsoftware.com

对于一个简单的示例，通过执行以下操作创建一个新的UI文件：

• 加载Qt设计器
• 创建一个新的Qt对话框
• 拖放QTreeWidget
• 右键单击并执行“更改objectName.‘>”uiOrbTREE“
• 右键单击小部件并选择“Promote.”
  • 保持基类名称不变(QTreeWidget)
  • 将“升级类名”设置为“XOrbTreeWidget”
  • 将“头文件”设置为“projexui.widgets.xorbtreewidget”
  • 单击“添加”，然后单击“推广”

​

• 选择基本对话框并单击“网格中的布局”
• 保存UI文件(代码中将它称为UI_FILE )

这将创建PyQt接口部分，接下来仍然需要将接口连接到数据库后端。如何使用ORB进行此操作的最简单示例是：

# import the projexui and orb libraries
import projexui
import orb

# import PyQt modules
import PyQt4.QtGui
import PyQt4.uic

# create our database model
class User(orb.Table):
    __db_columns__ = [
        orb.Column( orb.ColumnType.String, 'username' ),
        orb.Column( orb.ColumnType.String, 'password' ),
        orb.Column( orb.ColumnType.Boolean, 'isActive' )
    ]

# the above model will by default create a PostgreSQL table called default_user with
# the fields _id, username, password and is_active.  All of this is configurable, but
# you should read the docs for more info

# create the database information
db = orb.Database('Postgres', DATABASE_NAME) # set your db name
db.setUsername(USER_NAME) # set your db user name
db.setPassword(PASSWORD)  # set your password
db.setHost('localhost')   # set your host
db.setPort(5432)          # set your port

# register the database
orb.Orb.instance().registerDatabase(db)

# sync the datbase (this will create your tables, update columns, etc.)
# NOTE: this should not always be called, it is here as an example
db.sync( dryRun = False ) # dryRun will just output the SQL calls

#-----------------------------
# End Database Code
#-----------------------------

class ExampleDialog(QtGui.QDialog):
    def __init__( self, parent = None ):
        super(ExampleDialog, self).__init__(parent)

        # load your UI file
        PyQt4.uic.loadUi(UI_FILE, self) # use the UI_FILE you saved

        # connect the tree to the model
        self.uiOrbTREE.setTableType(User)

        # that is all you have to do to link the tree to the model and vice-versa,
        # this is the most simple example of how to do this - you can do more as far
        # as linking queries and sorting and such, but you should read the docs on
        # the site

# launch as an application
if ( __name__ == '__main__' ):
    # always check for an existing application first!
    app = None
    if ( not QtGui.QApplication.instance() ):
        app = QtGui.QApplication(sys.argv)

    dialog = ExampleDialog()
    dialog.show()

    # execute the app if we created it
    if ( app ):
        app.exec_()