Python使用pyodbc访问数据库操作方法详解

import pyodbc 

DBfile = r"F:\python\caiji.mdb" # 数据库文件需要带路径
print(DBfile)
conn = pyodbc.connect(r"DRIVER={Microsoft Access Driver (*.mdb, *.accdb)};DBQ="+ DBfile +";Uid=;Pwd=;") 
cursor = conn.cursor() 
SQL = "SELECT * from sites;" 
for row in cursor.execute(SQL): 
 print(row) 
cursor.close() 
conn.close() 

# -*-coding:utf-8-*-
import pyodbc

# 连接数据库（不需要配置数据源）,connect()函数创建并返回一个 Connection 对象
cnxn = pyodbc.connect(r'DRIVER={Microsoft Access Driver (*.mdb, *.accdb)};DBQ=.\data\goods.mdb')
# cursor()使用该连接创建（并返回）一个游标或类游标的对象
crsr = cnxn.cursor()

# 打印数据库goods.mdb中的所有表的表名
print('`````````````` goods ``````````````')
for table_info in crsr.tables(tableType='TABLE'):
  print(table_info.table_name)


l = crsr.execute("SELECT * from goods WHERE goodsId='0001'")# [('0001', '扇叶', 20, 'A公司', 'B公司', 2000, 2009)]

rows = crsr.execute("SELECT currentStock from goods") # 返回的是一个元组
for item in rows:
  print(item)

l = crsr.execute("UPDATE users SET username='lind' WHERE password='123456'")
print(crsr.rowcount) # 想知道数据修改和删除时，到底影响了多少条记录，这个时候你可以使用cursor.rowcount的返回值。

# 修改数据库中int类型的值
value = 10
SQL = "UPDATE goods "    "SET lowestStock=" + str(value) + " "    "WHERE goodsId='0005'"

# 删除表users
crsr.execute("DROP TABLE users")
# 创建新表 users
crsr.execute('CREATE TABLE users (login VARCHAR(8),userid INT, projid INT)')
# 给表中插入新数据
crsr.execute("INSERT INTO users VALUES('Linda',211,151)")

''''''
# 更新数据
crsr.execute("UPDATE users SET projid=1 WHERE userid=211")

# 删除行数据
crsr.execute("DELETE FROM goods WHERE goodNum='0001'")

# 打印查询的结果
for row in crsr.execute("SELECT * from users"):
  print(row)


# 提交数据（只有提交之后，所有的操作才会对实际的物理表格产生影响）
crsr.commit()
crsr.close()
cnxn.close()

cnxn =pyodbc.connect('DRIVER={SQL Server};SERVER=localhost;DATABASE=testdb;UID=me;PWD=pass')
cursor =cnxn.cursor()

cnxn =pyodbc.connect('DSN=test;PWD=password')
cursor =cnxn.cursor()

cursor.execute("select user_id, user_name from users")
row =cursor.fetchone()
if row:
 printrow

cursor.execute("select user_id, user_name from users")
row =cursor.fetchone()
print'name:', row[1]  # access by column index
print'name:', row.user_name # or access by name

while 1:
 row= cursor.fetchone()
 ifnot row:
 break
 print'id:', row.user_id

cursor.execute("select user_id, user_name from users")
rows =cursor.fetchall()
for row in rows:
 printrow.user_id, row.user_name

cursor.execute("select user_id, user_name from users"):
for row in cursor:
 printrow.user_id, row.user_name

for row in cursor.execute("select user_id, user_name from users"):
 printrow.user_id, row.user_name

cursor.execute("""
  select user_id, user_name
   from users
  where last_logon < '2001-01-01'
   and bill_overdue = 'y'
  """)

cursor.execute("""
  select user_id, user_name
   from users
  where last_logon < """,'2001-01-01','y')

cursor.execute("""
  select user_id, user_name
   from users
  where last_logon < """, ['2001-01-01','y'])

cursor.execute("select count(*) as user_count from users where age > ",21)
row =cursor.fetchone()
print'%d users' %row.user_count

cursor.execute("insert into products(id, name) values ('pyodbc', 'awesome library')")
cnxn.commit()

cursor.execute("insert into products(id, name) values (",'pyodbc', 'awesome library')
cnxn.commit()

cursor.execute("delete from products where id <> ",'pyodbc')
printcursor.rowcount, 'products deleted'
cnxn.commit()

deleted =cursor.execute("delete from products where id <> 'pyodbc'").rowcount
cnxn.commit()

deleted =cursor.execute("delete from products where id <> 'pyodbc'").rowcount

deleted =cursor.execute("""
    delete
    from products
    where id <> 'pyodbc'
    """).rowcount

row =cursor.execute("select count(*) as user_count from users").fetchone()
print'%s users' %row.user_count

count =cursor.execute("select count(*) from users").fetchone()[0]
print'%s users' %count

maxid =cursor.execute("select coalesce(max(id), 0) from users").fetchone()[0]