sqlalchemy

问题 I am trying to setup a database just like in a tutorial but I am getting a programming error that a table doesn't exist when I'm trying to add a User This is the file that errors ( database.py ): from sqlalchemy import create_engine, MetaData from sqlalchemy.orm import scoped_session, sessionmaker from sqlalchemy.ext.declarative import declarative_base engine = create_engine( "mysql+pymysql://testuser:testpassword@localhost/test?charset=utf8", connect_args = { "port": 3306 }, echo="debug",

问题 I want to get all the columns of a table with max(timestamp) and group by name. What i have tried so far is: normal_query ="Select max(timestamp) as time from table" event_list = normal_query \ .distinct(Table.name)\ .filter_by(**filter_by_query) \ .filter(*queries) \ .group_by(*group_by_fields) \ .order_by('').all() the query i get : SELECT DISTINCT ON (schema.table.name) , max(timestamp).... this query basically returns two columns with name and timestamp. whereas, the query i want : SELECT

问题 I want to get all the columns of a table with max(timestamp) and group by name. What i have tried so far is: normal_query ="Select max(timestamp) as time from table" event_list = normal_query \ .distinct(Table.name)\ .filter_by(**filter_by_query) \ .filter(*queries) \ .group_by(*group_by_fields) \ .order_by('').all() the query i get : SELECT DISTINCT ON (schema.table.name) , max(timestamp).... this query basically returns two columns with name and timestamp. whereas, the query i want : SELECT

问题 In sqlalchemy, I make the connection: conn = engine.connect() I found this will set autocommit = 0 in my mysqld log. Now I want to set autocommit = 1 because I do not want to query in a transaction. Is there a way to do this? 回答1: From The SQLAlchemy documentation: Understanding autocommit conn = engine.connect() conn.execute("INSERT INTO users VALUES (1, 'john')") # autocommits The “autocommit” feature is only in effect when no Transaction has otherwise been declared. This means the feature

问题 In sqlalchemy, I make the connection: conn = engine.connect() I found this will set autocommit = 0 in my mysqld log. Now I want to set autocommit = 1 because I do not want to query in a transaction. Is there a way to do this? 回答1: From The SQLAlchemy documentation: Understanding autocommit conn = engine.connect() conn.execute("INSERT INTO users VALUES (1, 'john')") # autocommits The “autocommit” feature is only in effect when no Transaction has otherwise been declared. This means the feature

问题 In sqlalchemy, I make the connection: conn = engine.connect() I found this will set autocommit = 0 in my mysqld log. Now I want to set autocommit = 1 because I do not want to query in a transaction. Is there a way to do this? 回答1: From The SQLAlchemy documentation: Understanding autocommit conn = engine.connect() conn.execute("INSERT INTO users VALUES (1, 'john')") # autocommits The “autocommit” feature is only in effect when no Transaction has otherwise been declared. This means the feature

问题 I am trying to migrate a SQL database using sqlAlchemy and Alembic. I would like to make simple migration scripts directly in Python code, and not by using Alembic CLI, as described in the docs. I only found this SO question on this topic: Using Alembic API from inside application code Using this question + Flask-Alembic source code, I tried these simple commands. engine is linked to my db & metadata contains the information for the migration. I think I am very close, and the solution should

问题 I am trying to migrate a SQL database using sqlAlchemy and Alembic. I would like to make simple migration scripts directly in Python code, and not by using Alembic CLI, as described in the docs. I only found this SO question on this topic: Using Alembic API from inside application code Using this question + Flask-Alembic source code, I tried these simple commands. engine is linked to my db & metadata contains the information for the migration. I think I am very close, and the solution should

问题 I have been googling and reading through the SQLAlchemy documentation but haven't found what I am looking for. I am looking for a function in SQLAlchemy that limits the number of results returned by a query to a certain number, for example: 5? Something like first() or all() . 回答1: for sqlalchemy >= 1.0.13 Use the limit method. query.(Model).filter(something).limit(5).all() 回答2: Alternative syntax query.(Model).filter(something)[:5].all() 回答3: In my case it works like def get_members(): m =

问题 I have been googling and reading through the SQLAlchemy documentation but haven't found what I am looking for. I am looking for a function in SQLAlchemy that limits the number of results returned by a query to a certain number, for example: 5? Something like first() or all() . 回答1: for sqlalchemy >= 1.0.13 Use the limit method. query.(Model).filter(something).limit(5).all() 回答2: Alternative syntax query.(Model).filter(something)[:5].all() 回答3: In my case it works like def get_members(): m =