SQL语句大全 –语 句功能 –数据操作 SELECT –从数据库表中检索数据行和列 INSERT –向数据库表添加新数据行 DELETE –从数据库表中删除数据行 UPDATE –更新数据库表中的数据 -数据定义 CREATE TABLE –创建一个数据库表 DROP TABLE –从数据库中删除表 ALTER TABLE –修改数据库表结构 CREATE VIEW –创建...
-- 语法 GROUPING ( <column_expression> )3.4.4.2 GROUPING_ID() 计算分组级别的函数。仅当指定了 GROUP BY 时,GROUPING_ID 才能在 SELECT列表、HAVING 或 ORDER BY 子句中使用。 代码语言:javascript 代码运行次数:0 运行 AI代码解释 --语法GROUPING_ID(<column_expression>[,...n]) 3.4.4.3 OVER子句 OV...
SELECTcustomer_nameFROMcustomersWHEREcustomer_idIN(SELECTcustomer_idFROMtransactionsWHEREamount>1000);--...
这里的引用有点面向对象的意思: database.table.column -- Btw, 这种引用方法面向对象的Python的主流,SQL只是偶尔一用,而Stata 一律不用(因为”.“是一个 Stata 的因子运算符)。 USE db1 ## 指定使用 db1 数据库后,后面的table前面的数据库可以省略不写 SELECT id from db1.table1 ## 从 db1 的 table...
1.select column_name from information_schema.columns where table_schema=‘database_name’ and table_name=‘users’; 2.select group_concat(column_name) from information_schema.columns where table_schema=database() and table_name=‘flag’; ...
REPLACE---搜索指定字符串并替换 格式∶REPLACE(string , substring , replace_string) 例∶ REPLACE(‘this is a test’ , ‘this’ , ‘that an’)=’that an is a test’ TRIM---删除字符串前缀或尾随字符 格式∶TRIM( [LEADING | TRAILING |BOTH] [ trimchar FROM ] string) ...
Replacecolumn_nameandtable_namewith the existing names in your database andalias_name –with your chosen custom alias. Break Down SQL Statements Breaking down complex SQL statements into smaller, manageable parts can help you easily identify errors. By testing smaller parts of your SQL code, you...
select *(列名) from table_name(表名) where column_name operator value ex 宿主) select * from stock_information where stockid = str(nid) stockname = "str_name" stockname like "% find this %" stockname like "[a-zA-Z]%" --- ([]指定值的范围) stockname ...
(3, 'Jerry'); INSERT 0 3 -- 执行失败时,不设置变量 SELECT id, name FROM student ORDER BY idi; ERROR: column "idi" does not exist LINE 1: SELECT id, name FROM student ORDER BY idi; ^ \echo ${id} ${name} ${id} ${name} -- 执行结果为多条记录时,使用特定字符串拼接 SELECT id...
Let's give an example. The following PL/SQL function called IS_PRESIDENT finds out if an employee from table EMP has the job role PRESIDENT. To accomplish that we only need to check the value of the column MGR. If the value is 1, the employee has the job role PRESIDENT. ...