使用 Python，导出 SQLite 模式

Question

在 SQLite 命令行中，命令.schema 可用于以 SQL 语法导出数据库模式，该导出可用于重建相同结构的数据库：

.output folderpath/schema.sql
.schema

将以下内容保存到名为“schema.sql”的文件中：

CREATE TABLE mytable (id INTEGER NOT NULL, name TEXT NOT NULL, date DATETIME, PRIMARY KEY (id), FOREIGN KEY (name) REFERENCES mytable2 (na ...

是否可以在没有自定义函数的情况下使用 Python 的 sqlite3 库实现相同的输出 .sql 文件？ Stack Overflow 上有几个类似标题的问题，但我没有找到任何真正试图获取完整架构的问题（他们实际上是在寻找没有 CREATE TABLE 等语句的PRAGMA table_info 输出中的语句)。

Answer 1

嗯。重写了上面的答案。这正是您所需要的？

import sqlite3

dbname = 'chinook.db'

with sqlite3.connect(dbname) as con:
    cursor = con.cursor()
    cursor.execute('select sql from sqlite_master')
    for r in cursor.fetchall():
        print(r[0])
    cursor.close()

使用测试 sqlite3 数据库，我收到以下信息：

CREATE TABLE "albums"
(
    [AlbumId] INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,
    [Title] NVARCHAR(160)  NOT NULL,
    [ArtistId] INTEGER  NOT NULL,
    FOREIGN KEY ([ArtistId]) REFERENCES "artists" ([ArtistId]) 
                ON DELETE NO ACTION ON UPDATE NO ACTION
)
CREATE TABLE sqlite_sequence(name,seq)
CREATE TABLE "artists"
(
    [ArtistId] INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,
    [Name] NVARCHAR(120)
)
CREATE TABLE "customers"
(
    [CustomerId] INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,
    [FirstName] NVARCHAR(40)  NOT NULL,
    [LastName] NVARCHAR(20)  NOT NULL,
    [Company] NVARCHAR(80),
    [Address] NVARCHAR(70),
    [City] NVARCHAR(40),
    [State] NVARCHAR(40),
    [Country] NVARCHAR(40),
    [PostalCode] NVARCHAR(10),
    [Phone] NVARCHAR(24),
    [Fax] NVARCHAR(24),
    [Email] NVARCHAR(60)  NOT NULL,
    [SupportRepId] INTEGER,
    FOREIGN KEY ([SupportRepId]) REFERENCES "employees" ([EmployeeId]) 
                ON DELETE NO ACTION ON UPDATE NO ACTION
)
CREATE TABLE "employees"
(
    [EmployeeId] INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,
    [LastName] NVARCHAR(20)  NOT NULL,
    [FirstName] NVARCHAR(20)  NOT NULL,
    [Title] NVARCHAR(30),
    [ReportsTo] INTEGER,
    [BirthDate] DATETIME,
    [HireDate] DATETIME,
    [Address] NVARCHAR(70),
    [City] NVARCHAR(40),
    [State] NVARCHAR(40),
    [Country] NVARCHAR(40),
    [PostalCode] NVARCHAR(10),
    [Phone] NVARCHAR(24),
    [Fax] NVARCHAR(24),
    [Email] NVARCHAR(60),
    FOREIGN KEY ([ReportsTo]) REFERENCES "employees" ([EmployeeId]) 
                ON DELETE NO ACTION ON UPDATE NO ACTION
)
CREATE TABLE "genres"
(
    [GenreId] INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,
    [Name] NVARCHAR(120)
)
CREATE TABLE "invoices"
(
    [InvoiceId] INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,
    [CustomerId] INTEGER  NOT NULL,
    [InvoiceDate] DATETIME  NOT NULL,
    [BillingAddress] NVARCHAR(70),
    [BillingCity] NVARCHAR(40),
    [BillingState] NVARCHAR(40),
    [BillingCountry] NVARCHAR(40),
    [BillingPostalCode] NVARCHAR(10),
    [Total] NUMERIC(10,2)  NOT NULL,
    FOREIGN KEY ([CustomerId]) REFERENCES "customers" ([CustomerId]) 
                ON DELETE NO ACTION ON UPDATE NO ACTION
)
CREATE TABLE "invoice_items"
(
    [InvoiceLineId] INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,
    [InvoiceId] INTEGER  NOT NULL,
    [TrackId] INTEGER  NOT NULL,
    [UnitPrice] NUMERIC(10,2)  NOT NULL,
    [Quantity] INTEGER  NOT NULL,
    FOREIGN KEY ([InvoiceId]) REFERENCES "invoices" ([InvoiceId]) 
                ON DELETE NO ACTION ON UPDATE NO ACTION,
    FOREIGN KEY ([TrackId]) REFERENCES "tracks" ([TrackId]) 
                ON DELETE NO ACTION ON UPDATE NO ACTION
)
CREATE TABLE "media_types"
(
    [MediaTypeId] INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,
    [Name] NVARCHAR(120)
)
CREATE TABLE "playlists"
(
    [PlaylistId] INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,
    [Name] NVARCHAR(120)
)
CREATE TABLE "playlist_track"
(
    [PlaylistId] INTEGER  NOT NULL,
    [TrackId] INTEGER  NOT NULL,
    CONSTRAINT [PK_PlaylistTrack] PRIMARY KEY  ([PlaylistId], [TrackId]),
    FOREIGN KEY ([PlaylistId]) REFERENCES "playlists" ([PlaylistId]) 
                ON DELETE NO ACTION ON UPDATE NO ACTION,
    FOREIGN KEY ([TrackId]) REFERENCES "tracks" ([TrackId]) 
                ON DELETE NO ACTION ON UPDATE NO ACTION
)
None
CREATE TABLE "tracks"
(
    [TrackId] INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,
    [Name] NVARCHAR(200)  NOT NULL,
    [AlbumId] INTEGER,
    [MediaTypeId] INTEGER  NOT NULL,
    [GenreId] INTEGER,
    [Composer] NVARCHAR(220),
    [Milliseconds] INTEGER  NOT NULL,
    [Bytes] INTEGER,
    [UnitPrice] NUMERIC(10,2)  NOT NULL,
    FOREIGN KEY ([AlbumId]) REFERENCES "albums" ([AlbumId]) 
                ON DELETE NO ACTION ON UPDATE NO ACTION,
    FOREIGN KEY ([GenreId]) REFERENCES "genres" ([GenreId]) 
                ON DELETE NO ACTION ON UPDATE NO ACTION,
    FOREIGN KEY ([MediaTypeId]) REFERENCES "media_types" ([MediaTypeId]) 
                ON DELETE NO ACTION ON UPDATE NO ACTION
)
CREATE INDEX [IFK_AlbumArtistId] ON "albums" ([ArtistId])
CREATE INDEX [IFK_CustomerSupportRepId] ON "customers" ([SupportRepId])
CREATE INDEX [IFK_EmployeeReportsTo] ON "employees" ([ReportsTo])
CREATE INDEX [IFK_InvoiceCustomerId] ON "invoices" ([CustomerId])
CREATE INDEX [IFK_InvoiceLineInvoiceId] ON "invoice_items" ([InvoiceId])
CREATE INDEX [IFK_InvoiceLineTrackId] ON "invoice_items" ([TrackId])
CREATE INDEX [IFK_PlaylistTrackTrackId] ON "playlist_track" ([TrackId])
CREATE INDEX [IFK_TrackAlbumId] ON "tracks" ([AlbumId])
CREATE INDEX [IFK_TrackGenreId] ON "tracks" ([GenreId])
CREATE INDEX [IFK_TrackMediaTypeId] ON "tracks" ([MediaTypeId])
CREATE TABLE sqlite_stat1(tbl,idx,stat)