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Learn how to define an auto increment primary key in PostgreSQL. Get instructions on learning how to use the serial data type nd how to use a custom sequence. Sep 06, 2019 CREATE TABLE salespeople ( id INTEGER PRIMARY KEY, firstname TEXT NOT NULL, lastname TEXT NOT NULL, commissionrate REAL NOT NULL ); Inserting data with a SQLite autoincrement field When you have a database table with a SQLite autoincrement field, there are two ways to insert data into that table and automatically increment the primary key. Primarykeys = response. Insertedprimarykey 上記の例では社員名をEmployeeテーブルに登録して、Auto Incrementで自動採番されたemployeeidを配列で返しています。 最後までお読みいただきましてありがとうございました！. Class sqlalchemy.ext.automap.AutomapBase¶. Base class for an “automap” schema. The AutomapBase class can be compared to the “declarative base” class that is produced by the declarative.declarativebase function. In practice, the AutomapBase class is always used as a mixin along with an actual declarative base.

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Let us now discuss how to use the create table function.

The SQL Expression Language constructs its expressions against table columns. SQLAlchemy Column object represents a column in a database table which is in turn represented by a Tableobject. Metadata contains definitions of tables and associated objects such as index, view, triggers, etc.

Hence an object of MetaData class from SQLAlchemy Metadata is a collection of Table objects and their associated schema constructs. It holds a collection of Table objects as well as an optional binding to an Engine or Connection.

Constructor of MetaData class can have bind and schema parameters which are by default None.

Next, we define our tables all within above metadata catalog, using the Table construct, which resembles regular SQL CREATE TABLE statement.

An object of Table class represents corresponding table in a database. The constructor takes the following parameters −

Column object represents a column in a database table. Constructor takes name, type and other parameters such as primary_key, autoincrement and other constraints.

SQLAlchemy matches Python data to the best possible generic column data types defined in it. Some of the generic data types are −

• BigInteger
• Boolean
• Date
• DateTime
• Float
• Integer
• Numeric
• SmallInteger
• String
• Text
• Time

To create a students table in college database, use the following snippet −

The create_all() function uses the engine object to create all the defined table objects and stores the information in metadata.

Complete code is given below which will create a SQLite database college.db with a students table in it.

Because echo attribute of create_engine() function is set to True, the console will display the actual SQL query for table creation as follows −

The college.db will be created in current working directory. To check if the students table is created, you can open the database using any SQLite GUI tool such as SQLiteStudio.

The below image shows the students table that is created in the database −

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  Aug 29, 2017