from sqlalchemy import func # count User records, without # using a subquery. session.query(func.count(User.id)) # return count of user "id" grouped # by "name" session.query(func.count(User.id)).\ group_by() f
init(), add_column(), add_columns(), add_entity(), all(), apply_labels(), as_scalar(), autoflush(), column_descriptions, correlate(), count(), cte(), delete(), distinct(), enable_assertions(), enable_eagerloads(), except_(), except_all(), execution_options(), exists(), filte...
connection = engine.connect() # direct string SQL not supported; use text() or exec_driver_sql() method result = connection.execute("select * from table") # positional parameters no longer supported, only named # unless using exec_driver_sql() result = connection.execute(table.insert(), (...
COUNT: COUNT is a function which provides the count of the row for a column. The column should be a not null column. SELECT COUNT(column_name) FROM table_name; 1. Output: On execution of this command, the result will contain the count of the rows for column_name. COUNT:COUNT是一项功...
init(), add_column(), add_columns(), add_entity(), all(), apply_labels(), as_scalar(), autoflush(), column_descriptions, correlate(), count(), cte(), delete(), distinct(), enable_assertions(), enable_eagerloads(), except_(), except_all(), execution_options(), exists(), filte...
Previously the default pool used was the NullPool that precented sharing the same database between multiple engines.References: #6379 mssql [mssql] [bug] [schema]Add TypeEngine.as_generic() support for sqlalchemy.dialects.mysql.BIT columns, mapping them to Boolean.References: #6345 [mssql] ...
group_by(User.name)fromsqlalchemyimportdistinct# count distinct "name" valuessession.query(func.count(distinct(User.name)))
query.distinct(): 去除查询结果中的重复记录。 query.count(): 返回查询结果的记录数量,通常与 filter 结合使用以实现条件查询的数量统计。 6.2 常用筛选器运算符 # 等于 query.filter(User.name == '张三') # 不等于 query.filter(User.name != '张三') # like query.filter(User.name.like('%张三%'...
我们可以使用 DISTINCT ()方法向 SELECT 语句添加 DISTINCT 选项。例如: from sqlalchemy import distinct session.query(Customer.town).filter(Customer.id < 10).all() session.query(Customer.town).filter(Customer.id < 10).distinct().all() session.query( func.count(distinct(Customer.town)), func....
1 2 3 4 5 6 7 8 9 SELECT COUNT (DISTINCT customers.town) AS count_1, COUNT (customers.town) AS count_2 FROM customers ['count_1', 'count_2'] [(3, 5)] Casting Casting (converting) data from one type to another is a common operation and is done via cast() function from the...