Use of Flask-SQL-Pro()

Based on flask-sqlalchemy function, add sql statements to separate, implement dynamic SQL through jinja2, and provide simple database operation plug-in.

Example: https://www.cnblogs.com/miaokela/articles/17571427.html

pip install flask-sql-pro

Register

Register in create_app

def create_app():
    # Register Flask-SQL-Pro objects, and register Flask-SQLAlchemy
    sqlpro = FlaskSQLPro()
    db = sqlpro.init_app(app)

Why return a db in init_app()? SQLAlchemy instance objects may be used for plug-in database operations such as Flask-Migrate

from flask_migrate import Migrate


Migrate(app, db)

Import in models.py

from flask_sql_pro import DataBaseHelper
from sqlalchemy import text
from sqlalchemy.dialects.mysql import TINYINT, BIGINT, VARCHAR, DATETIME, DOUBLE, INTEGER

# If you want to use db objects in other files: from project_path.models import db
db = DataBaseHelper.db

class BaseModel(db.Model):
    __abstract__ = True
    created_at = db.Column(DATETIME, comment='Create Time', server_default=text('Now()'))
    updated_at = db.Column(DATETIME, comment='Update Time', server_default=text('Now()'), onupdate=datetime.now())
    is_deleted = db.Column(TINYINT, comment='Logical delete or not', server_default=text('0'), index=True)

    @classmethod
    def queryset(cls):
        """
        Data that is not logically deleted
        """
        return cls.query.filter(cls.is_deleted == 0)

CRUD example

• Add

from flask_sql_pro import DataBaseHelper  # Master tool class
from app.models import db # SQLAlchemy Instance object

with db.trans():
    _id = DataBaseHelper.execute_create(
        'transit_record',  # Table name
        data=data,
    )

    if not _id:
        raise AddRecordException()

• Delete

with db.trans():
    rows = DataBaseHelper.execute_delete(
        'transit_record',
        where={
            'id': _id,
        },
        logic=True
    )
    if not rows:
        raise DelRecordException()

• Modify

with db.trans():
    rows = DataBaseHelper.execute_update(
        'transit_record',
        data=data,
        where={
            'id': _id
        }
    )
    if not rows:
        raise ModifyRecordException()

• Select

Create a folder to store SQL statements The default is Flask's instance_path path, which is project_path/instance/ The default SQL folder should be created in project_path/instance/sql To allow custom paths, configure the DB_HELPER_SQL_FILE_PATH parameter

import os


class BaseConfig:
    BASE_DIR = os.path.dirname(os.path.realpath(__file__))
    APP_DIR = os.path.join(BASE_DIR, 'app')
    DB_HELPER_SQL_FILE_PATH = os.path.join(
        APP_DIR,
        'sql'
    )

# Register the configuration when creating a Flask application
# __init__.py
def create_app():
    # ...
    app.config.from_object(BaseConfig())
    # ...

Other Flask-SQL-Pro configurations

DB_HELPER_LOGIC_DELETE_FLAG = 'delete_flag'  # The default logic delete flag name, The value of the flag for logical deletion is 1 and cannot be modified
DB_HELPER_PAGE_PARAM = 'page'  # The default page number
DB_HELPER_PAGE_SIZE_PARAM = 'page_size'  # Default number of pages per page
DB_HELPER_PRINT_MSG = True  # Whether to print SQL execution statements on the terminal

Query example

Files: sql/transit/index.yml

query_map: |
    SELECT
        TRG.latitude,
        TRG.longitude,
        TRG.location,
        TRG.location_type
    FROM
        transit_record_gps AS TRG
    LEFT JOIN
        transit_record AS TR
    ON
        TRG.transit_record_id = TR.id
    WHERE
        TRG.is_deleted = 0
    AND
        TR.is_deleted = 0
    AND
        TR.id = :transit_record_id

Files: app/api/transit.py

transit_record_gps = DataBaseHelper.select_all(
    'transit.index.query_map',
    params={
        'transit_record_id': transit_record_id
    },
    return_obj=False,  # The default value of return_obj is True, which means that the object can obtain data from the transit_record_gps[0].transit_record_id point. If False, the dictionary is returned
)

• Pagination

The default parameter that needs to be passed is page/page_size, and paging occurs when both parameters are passeds

Files: sql/history/index.yml

select_user_experiments: |
    SELECT
        experiment_id,
        experiment_name,
        date_format(update_datetime,"%Y-%m-%d") update_time
    FROM
        data_experiment_record
    WHERE
        delete_flag = 0

experiments = DataBaseHelper.select_all(
    'history.index.select_user_experiments',
    params={
        'account_id': account_id,
    },
    options={
        'page': 1,
        'page_size': 20,
    }
)

• Dynamic SQL

With jinja2, conditional statement is realized and SQL is generated dynamically

Files: sql/experiment/index.yml

select_history_data_by_id_and_time: |
    SELECT
        daedd.daq_data_id daqDataId,
        daedd.vel_rms_value rmsVelocityValue,
        daedd.peak_value peakValue,
        daedd.peak_to_peak_value peaToPeakValue,
        daedd.skewness_value skewnessValue,
        daedd.mean_value meanValue,
        daedd.kurtosis_value kurtosisValue,
        daedd.rms_value rmsRawValue,
        daedd.rpm_value rpmValue,
        DATE_FORMAT(daedd.collection_datetime, '%Y-%m-%d %H:%i:%S') collectionDatetime
    FROM
        data_acquisition_equipment_daq_data daedd
    LEFT JOIN
        data_acquisition_equipment_daq_data_config daeddc
    ON
        daedd.data_config_id = daeddc.config_id
    WHERE
        daedd.sensor_id = :sensor_id
    {% if query_start_time and query_end_time %}
    AND
        daedd.collection_datetime BETWEEN :query_start_time AND :query_end_time
    {% endif %}
    {% if experiment_id %}
    AND
        daedd.experiment_id = :experiment_id
    {% endif %}
    ORDER BY daedd.collection_datetime ASC

Files: app/api/experiment.py

daq_data_list = DataBaseHelper.select_all(
    "experiment.index.select_history_data_by_id_and_time",
    params={
        "sensor_id": query.sensorId,
        "query_start_time": query.queryStartTime,
        "query_end_time": query.queryEndTime,
        "experiment_id": experiment_id,
    },
    options={
        "query_start_time": query.queryStartTime,
        "query_end_time": query.queryEndTime,
        "experiment_id": experiment_id,
    },
)

• Multi-database operation

You want to operate other databases other than the database corresponding to the SQLALCHEMY_DATABASE_URI configured in the system

Configuration parameter

class BaseConfig:
    SQLALCHEMY_BINDS = {
        'cloud': 'mysql+pymysql://root:[email protected]:3306/cloud_db?charset=utf8'
    }

Give an example

add = DataBaseHelper.execute_create(
    'daq_data',
    data=online_data,
    app=cp,  # from flask import current_app as cp
    bind='cloud'  # Specifies the database for Bind
)
if not add:
    raise Exception('Description Failed to push online data')

DataBaseHelper.commit()

• Transaction

No commit by default, commit using databaseHelper.mit (), or through the db.trans() context transaction

from app.models import db

with db.trans():
    add = DataBaseHelper.execute_create(
        'daq_data',
        data=online_data,
        app=cp,  # from flask import current_app as cp
        bind='cloud'  # Specifies the database for Bind
    )
    if not add:
        raise Exception('Description Failed to push online data')