AI代码解释 ---Table structureforgrade---DROPTABLEIFEXISTS`grade`;CREATETABLE`grade`(`id`int(11)NOTNULLAUTO_INCREMENTCOMMENT'id',`sno`varchar(20)CHARACTERSETutf8COLLATEutf8_unicode_ciNULLDEFAULTNULLCOMMENT'学号',`courseName`varchar(20)CHARACTERSETutf8COLLATEutf8_unicode_ciNULLDEFAULTNULLCOMMENT'课程...
01列的定义必须放在圆括号02Createtable表 中。名 ○语法中参数顺序不 能改动。(○最多可以设置1024个字段 列名1列属性,列名2列属性,……列名n列属性 )列属性：如数据类型、null、默认值等 例：建立一个“student”表 CREATETABLEStudent (fCodevarchar(9)NOTNULL,fNamevarchar(10)NOTNULL,fSex char(2)NOT...
CREATE#这里告诉我们CREATE命令需要和那些命令一起使用Many help itemsforyour request exist.Tomake a more specific request, please type'help <item>',where<item>isoneofthe following topics:CREATEDATABASECREATEEVENTCREATEFUNCTIONCREATEFUNCTIONUDFCREATEINDEXCREATEPROCEDURECREATERESOURCEGROUPCREATEROLECREATESERVERCREATE...
PostgreSQL支持动态SQL,以PL/Pgsql为例,语法如下: EXECUTE command-string [ INTO [STRICT] target ] [ USING expression [, … ] ]; 上式中的可选项target表示a record variable, a row variable, or a comma-separated list of simple variables and record/row fields。如果要返回结果集,那么需要用到RETURN...
CREATE TABLE T1 ( column_1 int, column_2 varchar(30)); GO CREATE VIEW V1 AS SELECT column_2, column_1 FROM T1; GO INSERT INTO V1 VALUES ('Row 1',1); GO SELECT * FROM T1; GO SELECT * FROM V1; GO(2)UPDATE语句UPDATE...
-- Skipping the column list, but keeping the values in orderINSERTdbo.ProductsVALUES(75,'Tire Bar',NULL,'Tool for changing tires.')GO 只要在默认架构中访问和更改表,架构名称就是可选的。 由于ProductDescription列允许 Null 值,而且没有提供值,因此可以从语句中完全删除ProductDescription列的名称和值。
('hello', '1', 2); he -- Downcasting of a BIGINT to an INT > SELECT substring('hello', 1L, 2); he -- Crosscasting from STRING to INTEGER > SELECT substring('hello', str, 2) FROM VALUES(CAST('1' AS STRING)) AS T(str); he -- Crosscasting from INTEGER to STRING > ...
@Testpublic void testBatchInsert() {System.out.println("--- batch insert method test ---");List<User> list = new ArrayList<>();for (int i = 0; i < 10; i++) {User user = new User();user.setName("test");user.setAge(13);user.setEmail("101@qq.com");list.add(user);}us...
//演示代码中非直接sql模式设置条件模式进行记录修改 public Long updateByQuery() { return lightDao.updateByQuery(StaffInfoVO.class, EntityUpdate.create().set("createBy", "S0001") .where("staffName like ?").values("张")); } //代码中非直接sql模式设置条件模式进行记录删除 lightDao.deleteByQuery...
'mutate_type', 'appendonly'); --day是分区列,要出现在视图的group by的条件中 CREATE MATERIALIZED VIEW mv_sales_p AS SELECT day, hour, avg(amount) AS amount_avg FROM base_sales_p GROUP BY day, hour; COMMIT; create table base_sales_20220101 partition of base_sales_p for values in('202...