While different SQL flavors may require slight changes in syntax, the above DDL commands are largely the same no matter what version of SQL you are using. DDL Commands vs Other Types of Commands In the previous section, I explained how DDL commands define the structure of tables and update ...
named "users," you can use the following syntax:CREATE TABLE users (id INT PRIMARY KEY,name VARCHAR(50),email VARCHAR(100));这段中文翻译：SQL（结构化查询语言）是一种用于管理和操作关系数据库的标准编程语言。在本回答中，我将详细解释SQL数据定义语言（DDL）语句，它们用于定义数据库的结构和模式。
GaussDB(DWS) What's New Product Bulletin Function Overview Service Overview Getting Started Management Guide Best Practices Data Migration and Synchronization Developer Guide SQL Syntax Reference SQL Syntax Reference (9.1.0.x) SQL Syntax Reference (8.1.3.x) GaussDB(DWS) SQL Overview Differences ...
MySQL [test]> alter table t1 drop primary key; ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your OceanBase version for the right syntax to use near 'primary key' at line 1 MySQL [test]> alter table t1 add primary key (`time`); ...
syntaxsql sys.sp_cdc_get_ddl_history[ @capture_instance= ]'capture_instance'[ ; ] 参数 [ @capture_instance = ] 'capture_instance' 与源表关联的捕获实例的名称。@capture_instance是sysname,不能NULL。 返回代码值 0(成功)或1(失败)。
classid, objid, objsubid, command_tag, object_type, schema_name, object_identity, in_extensionFROMpg_event_trigger_ddl_commands();END; $$LANGUAGEplpgsql;CREATEFUNCTION
Drop syntax: DROP TABLE name Primary Key Support All key columns must be comparable. Use of a primary key creates a clustered index that supports search improvements for comparison, in, like, and order by. Null is an allowable primary key value, but there mus...
Java面向对象系列[v1.0.0][SQL语法之DDL] SQL语法基础 SQL全称是Structured Query Language也就是结构化查询语言,它是操作和检索关系数据库的标准语言,标准的SQL语句可以用于操作任何关系数据库,标准的SQL语句通常分为几个类型: 查询语句:由Select关键字完成,查询语句是SQL中最复杂,功能最丰富的语句...
运行时动态注册切换数据源,自动生成SQL(DDL/DML/DQL),读写元数据,对比数据库结构差异。适配100+关系/非关系数据库。 常用于动态场景的底层支持,如:数据中台、可视化、低代码后台、工作流、自定义表单、异构数据库迁移同步、物联网车联网数据处理、数据清洗、运行时自定义
the building blocks of SQL syntax,Chapter 12,Data Typesfor the data types to use for MySQL table columns,Chapter 14,SQL Statement Syntaxfor details about SQL statements and their associated categories, andChapter 13,Functions and Operatorsfor standard and MySQL-specific functions to use in queries...