如何使用 python 删除 sqlite3 中的所有表？

Question

i made a project which collects data from user and store it on different tables, the application has a delete function which the first option is to delete a specific table which is i already did and the second one is to delete all existing tables.

How can i drop all tables inside my database?

so this is my variables.

    conn = sqlite3.connect('main.db')
    cursor = conn.execute("DROP TABLE")

    cursor.close()

Answer 1

How can i drop all tables inside my database?

According to sqlitetutorial.net

SQLite allows you to drop only one table at a time. To remove multiple tables, you need to issue multiple DROP TABLE statements.

Answer 2

You can do it by querying all table names ( https://www.sqlite.org/faq.html#q7 )

Then you can use the result to delete the tables one by one

Here is the code, the function delete_all_tables does that

TABLE_PARAMETER = "{TABLE_PARAMETER}"
DROP_TABLE_SQL = f"DROP TABLE {TABLE_PARAMETER};"
GET_TABLES_SQL = "SELECT name FROM sqlite_schema WHERE type='table';"


def delete_all_tables(con):
    tables = get_tables(con)
    delete_tables(con, tables)


def get_tables(con):
    cur = con.cursor()
    cur.execute(GET_TABLES_SQL)
    tables = cur.fetchall()
    cur.close()
    return tables


def delete_tables(con, tables):
    cur = con.cursor()
    for table, in tables:
        sql = DROP_TABLE_SQL.replace(TABLE_PARAMETER, table)
        cur.execute(sql)
    cur.close()

Answer 3

SQLite3 code to issue multiple DROP TABLE statements based on TEMP_% name wildcard:

.output droptables.sql
SELECT "DROP TABLE """|| sqlite_master.name ||""";" FROM sqlite_master 
WHERE type = "table" AND sqlite_master.name LIKE 'TEMP_%';
.read droptables.sql

Example result in.sql output file:

DROP TABLE "TEMP_table1";
DROP TABLE "TEMP_table2";
DROP TABLE "TEMP_table3";
...

Python3 to paste SQL into:

 conn = sqlite3.connect(f"main.db")
 conn.row_factory = sqlite3.Row
 dbc = conn.cursor()

 dbc.execute(
            f"DROP TABLE 'TEMP_table1';"
    )
 conn.commit()