📜  Python SQLite-简介

📅  最后修改于: 2020-11-06 05:54:20             🧑  作者: Mango


可以使用由Gerhard Haring编写的sqlite3模块将SQLite3与Python集成。它提供了一个符合PEP 249描述的DB-API 2.0规范的SQL接口。您不需要单独安装此模块,因为它是默认随Python 2.5.x版一起提供的。

要使用sqlite3模块,必须首先创建一个代表数据库的连接对象,然后可以选择创建一个游标对象,该对象将帮助您执行所有SQL语句。

Python SQLite3模块API

以下是重要的sqlite3模块例程,这些例程可以满足您从Python程序使用SQLite数据库的要求。如果您正在寻找更复杂的应用程序,则可以查看Python sqlite3模块的官方文档。

Sr.No. API & Description
1

sqlite3.connect(database [,timeout ,other optional arguments])

This API opens a connection to the SQLite database file. You can use “:memory:” to open a database connection to a database that resides in RAM instead of on disk. If database is opened successfully, it returns a connection object.

2

connection.cursor([cursorClass])

This routine creates a cursor which will be used throughout your database programming with Python. This method accepts a single optional parameter cursorClass. If supplied, this must be a custom cursor class that extends sqlite3.Cursor.

3

cursor.execute(sql [, optional parameters])

This routine executes an SQL statement. The SQL statement may be parameterized (i. e. placeholders instead of SQL literals). The sqlite3 module supports two kinds of placeholders: question marks and named placeholders (named style).

For example − cursor.execute(“insert into people values (?, ?)”, (who, age))

4

connection.execute(sql [, optional parameters])

This routine is a shortcut of the above execute method provided by the cursor object and it creates an intermediate cursor object by calling the cursor method, then calls the cursor’s execute method with the parameters given.

5

cursor.executemany(sql, seq_of_parameters)

This routine executes an SQL command against all parameter sequences or mappings found in the sequence sql.

6

connection.executemany(sql[, parameters])

This routine is a shortcut that creates an intermediate cursor object by calling the cursor method, then calls the cursor.s executemany method with the parameters given.

7

cursor.executescript(sql_script)

This routine executes multiple SQL statements at once provided in the form of script. It issues a COMMIT statement first, then executes the SQL script it gets as a parameter. All the SQL statements should be separated by a semi colon (;).

8

connection.executescript(sql_script)

This routine is a shortcut that creates an intermediate cursor object by calling the cursor method, then calls the cursor’s executescript method with the parameters given.

9

connection.total_changes()

This routine returns the total number of database rows that have been modified, inserted, or deleted since the database connection was opened.

10

connection.commit()

This method commits the current transaction. If you don’t call this method, anything you did since the last call to commit() is not visible from other database connections.

11

connection.rollback()

This method rolls back any changes to the database since the last call to commit().

12

connection.close()

This method closes the database connection. Note that this does not automatically call commit(). If you just close your database connection without calling commit() first, your changes will be lost!

13

cursor.fetchone()

This method fetches the next row of a query result set, returning a single sequence, or None when no more data is available.

14

cursor.fetchmany([size = cursor.arraysize])

This routine fetches the next set of rows of a query result, returning a list. An empty list is returned when no more rows are available. The method tries to fetch as many rows as indicated by the size parameter.

15

cursor.fetchall()

This routine fetches all (remaining) rows of a query result, returning a list. An empty list is returned when no rows are available.