无法在 PySide2 上加载 QMYSQL 驱动程序-数据库问题

Unable to load QMYSQL Driver on PySide2(无法在 PySide2 上加载 QMYSQL 驱动程序)

本文介绍了无法在 PySide2 上加载 QMYSQL 驱动程序的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！

问题描述

如何使用 Python3.8 和 Pyside2 (pip) 安装和加载 Qmysql 驱动程序?我已经尝试下载 git:qtbase 并从那里编译驱动程序，但我很幸运.

How can i install and load the Qmysql driver using Pyside2 (pip) with python3.8? I've already tried to download git:qtbase and compiled the driver from there but I had any luck.

推荐答案

_{这个答案不仅涵盖了 Linux 的安装，还涵盖了其他操作系统，此外它还适用于 pyqt5}

Qt 使用的二进制文件与 PyQt5/PySide2 使用的二进制文件相同，因为它们使用相同的基本代码，因此您必须编译插件.

The binaries used by Qt are the same ones used by PyQt5/PySide2 since they use the same base code so you will have to compile the plugins.

在这种情况下，要编译 mysql 插件，您必须遵循官方手册，总结起来就是:

In this case, to compile the mysql plugin you must follow the official manual, which in summary is:

安装依赖项，在本例中为 mysql-connector-c
安装与编译 pyqt5/pyside2 相同版本的 Qt，以及 Windows 上的 MSVC、Ubuntu 上的 build-essentials、MacOS 上的 XCode 等开发工具.
下载源代码，在本例中为 qtbase 存储库.
编译插件.

要通过编译库的版本找出 Qt 的版本，可以使用以下命令:

To find out the version of Qt with the version that the library was compiled with, the following can be used:

PyQt5

python -c "from PyQt5.QtCore import QT_VERSION_STR; print('Qt version', QT_VERSION_STR)"

PySide2

python -c "from PySide2.QtCore import qVersion; print('Qt version', qVersion())"

以上根据操作系统生成 libqsqlmysql.so、qsqlmysql.dll 或 libqsqlmysql.dylib.该文件必须粘贴在路径中:

The above generates libqsqlmysql.so, qsqlmysql.dll or libqsqlmysql.dylib depending on the OS. That file must be pasted in the path:

PyQt5:

python -c "import os; from PyQt5.QtCore import QLibraryInfo; print('QT_SQL_DRIVER_PATH', os.path.join(QLibraryInfo.location(QLibraryInfo.PrefixPath), 'plugins', 'sqldrivers'))"

PySide2:

python -c "import os; from PySide2.QtCore import QLibraryInfo; print('QT_SQL_DRIVER_PATH', os.path.join(QLibraryInfo.location(QLibraryInfo.PrefixPath), 'plugins', 'sqldrivers'))"

为了涵盖所有情况，我创建了一个 Github Actions 来生成二进制文件:

To cover all the cases I have created a Github Actions that generates the binaries:

mysql_plugin.yml

name: generate_mysql_plugin

on: [push]

jobs:
  ci:
    name: ${{ matrix.os.name }} Qt-${{ matrix.qt.qt_version }}
    runs-on: ${{ matrix.os.runs-on }}
    strategy:
      fail-fast: false
      matrix:
        os:
          - name: Windows
            extension: "dll"
            runs-on: windows-2019
          - name: Linux
            extension: "so"
            runs-on: ubuntu-20.04
          - name: MacOS
            extension: "dylib"
            runs-on: macos-10.15
        qt:
          - name: 5.15
            qt_version: 5.15.0
    steps:
      - name: Checkout
        uses: actions/checkout@v1
      - name: Install Qt
        uses: jurplel/install-qt-action@v2
        with:
          version: ${{ matrix.qt.qt_version }}
          dir: ${{ github.workspace }}/qt/
      - name: clone qtbase
        run: git clone -b ${{ matrix.qt.qt_version }} https://code.qt.io/qt/qtbase.git
      - name: Compile mysql plugin on Windows
        if: matrix.os.name == 'Windows'
        shell: cmd
        run: |
          choco install wget
          wget https://downloads.mysql.com/archives/get/p/19/file/mysql-connector-c-6.1.11-winx64.zip
          unzip mysql-connector-c-6.1.11-winx64.zip
          copy /y "mysql-connector-c-6.1.11-winx64liblibmysql.dll" .
          call "C:/Program Files (x86)/Microsoft Visual Studio/2019/Enterprise/VC/Auxiliary/Build/vcvars64.bat"
          cd qtbase/src/plugins/sqldrivers
          qmake -- MYSQL_INCDIR="${{ github.workspace }}mysql-connector-c-6.1.11-winx64include" MYSQL_LIBDIR="${{ github.workspace }}mysql-connector-c-6.1.11-winx64lib"
          nmake sub-mysql
          nmake install
      - name: Compile mysql plugin on Linux
        if: matrix.os.name == 'Linux'
        run: |
          wget https://downloads.mysql.com/archives/get/p/19/file/mysql-connector-c-6.1.11-linux-glibc2.12-x86_64.tar.gz
          tar zxvf mysql-connector-c-6.1.11-linux-glibc2.12-x86_64.tar.gz
          sudo cp mysql-connector-c-6.1.11-linux-glibc2.12-x86_64/lib/*.so /usr/lib/x86_64-linux-gnu
          sudo apt-get install freetds-dev
          cd qtbase/src/plugins/sqldrivers
          qmake
          cd mysql
          qmake
          make
          make install
      - name: Compile mysql plugin on MacOS
        if: matrix.os.name == 'MacOs'
        run: |
          brew install wget
          wget https://cdn.mysql.com/archives/mysql-connector-c/mysql-connector-c-6.1.11-macos10.12-x86_64.tar.gz
          tar zxvf mysql-connector-c-6.1.11-macos10.12-x86_64.tar.gz
          sudo cp mysql-connector-c-6.1.11-macos10.12-x86_64/lib/libmysqlclient.dylib mysql-connector-c-6.1.11-macos10.12-x86_64/lib/libmysqlclient_r.dylib
          sudo cp mysql-connector-c-6.1.11-macos10.12-x86_64/lib/libmysqlclient.18.dylib mysql-connector-c-6.1.11-macos10.12-x86_64/lib/libmysqlclient_r.18.dylib

          sudo cp mysql-connector-c-6.1.11-macos10.12-x86_64/lib/*.dylib /usr/local/lib
          cd qtbase/src/plugins/sqldrivers
          qmake -- MYSQL_PREFIX="${{ github.workspace }}/mysql-connector-c-6.1.11-macos10.12-x86_64"
          make sub-mysql
          cd mysql
          make install
      - name: upload
        uses: actions/upload-artifact@v2
        with:
          path: qtbase/src/plugins/sqldrivers/plugins/sqldrivers/*qsqlmysql.${{ matrix.os.extension }}
          name: mysqlplugin-${{ matrix.os.name }}-Qt${{ matrix.qt.name }}

前面的代码生成了插件，您可以在此处找到该插件.

The previous code generates the plugin that you can find here.

在 Ubuntu 的特定情况下，它可以简化为:

In the specific case of Ubuntu it can be reduced to: