#coding:utf-8 import datetime from sqlalchemy import create_engine from sqlalchemy.ext.declarative import declarative_base from sqlalchemy import Column, String, Integer, DateTime, Text Base = declarative_base() class User(Base): __tablename__="users" id = Column(Integer,primary_key=True) nam...
(select max(rev) from YourTable st where yt.id=st.id) 1. 2. 3. 4. Having an index on (id,rev) renders the subquery almost as a simple lookup...在(id,rev)上有一个索引几乎使子查询成为一个简单的查询... Following are comparisons to the solutions in @AdrianCarneiro's answer (subque...
cursor.execute('''CREATE TABLE IF NOT EXISTS users (id INT AUTO_INCREMENT PRIMARY KEY, name VARCHAR(255), age INT)''') # 插入数据 sql = "INSERT INTO users (name, age) VALUES (%s, %s)" val = ("Alice", 30) cursor.execute(sql, val) # 查询数据 cursor.execute("SELECT * FROM use...
c.execute('''CREATE TABLE paim("序号","排名","学校名称","省市","总分","生源质量","培养结果","社会声誉","科研规模","科研质量","顶尖成果","顶尖人才","科技服务","成果转化","学生国际化" )''') listinsheet=openpyxl.load_workbook(r'C:/Users/asus/python/新建文件夹/University_Rank.xl...
Why I'm getting no such table error?Why is it racy if I use a sql.Open("sqlite3", ":memory:") database?Each connection to ":memory:" opens a brand new in-memory sql database, so if the stdlib's sql engine happens to open another connection and you've only specified ":memory:...
table in the database is locked */ #define SQLITE_NOMEM 7 /* A malloc() failed */ #define SQLITE_READONLY 8 /* Attempt to write a readonly database */ #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ #define SQLITE_IOERR 10 /* Some kind of disk I/O...
3.不支持表的无损修改,也就是说不支持 ALTER TABLE ,这恐怕带来了不少麻烦。改变数据表结构就要重建表,不过有其他方法解决。 4.只支持 left join ,不过差不多够用了,对小型程序来说。 5.优化数据表恐怕比较麻烦。 优点还是很多的,我看了下: 1.安装方便 ...
//语法DROP TABLE database_name.table_name;//使用DROP TABLE Student; 4.插入 //语法1INSERTINTOTABLE_NAME[(column1,column2,column3,...columnN)]VALUES(value1,value2,value3,...valueN);//语法3INSERTINTOTABLE_NAMEVALUES(value1,value2,value3,...valueN);//使用INSERTINTOPerson(id,name,age,...
userusqlite::{Connection,Result};#[derive(Debug)]structPerson{id:i32,name:String,data:Option<Vec<u8>>,}fnmain()->Result<()>{letconn =Connection::open_in_memory()?;conn.execute("CREATE TABLE person (id INTEGER PRIMARY KEY,name TEXT NOT NULL,data BLOB)",(),// empty list of parameter...
LIKE 运算符 匹配通配符查询: import sqlite3 conn = sqlite3.connect(":memory:") c = conn.cursor()#创建游标 #SQL 语句(包含SQL 关键字、表名、列名)大小写不敏感 #创建table employee c.execute('''CREATE TABLE employee (ID INTEGER PRIMARY KEY, name TEXT , age INTEGER, address TEXT, salary ...