DML 和 TCL 的区别
先决条件–DDL、DML、TCL 和 DCL 1。数据操作语言(DML) : DML 用于操作数据库中的数据。例如 SQL 中的插入、更新、删除指令。
2。事务控制语言(TCL) : TCL 处理数据库中的事务。
DML 与 TCL 的区别:
| s No. | category | DoctorofModernLanguages 现代语言博士 | TCL 集团股份有限公司（TCL Corporation 的缩写） | | --- | --- | --- | --- | | 1。 | Complete form | DML stands for data operation language. | TCL stands for transaction control language. | | 2。 | definition | DML stands for data manipulation language, which is used to manipulate data in the database by performing insert, update and delete operations. | Transaction control language (TCL) is composed of commands for processing transactions in the database. | | 3。 | classify | Data modification languages are further divided into procedural and non-procedural DML. | Transaction control languages are not further classified. | | 4。 | Characteristic display of database management system | It shows the easy-to-maintain features of (files). | Show the characteristics of atomicity. | | 5。 | Use in transactions | DML cannot be used for database transactions. | TCL is used to handle database transactions. | | 6。 | sequence | DML statements are usually written before TCL statements in queries. | TCL statements are usually written after DML statements in queries. | | 7。 | Use log files | It does not use log files. | It uses log files to keep records of all transactions. | | 8。 | order | Commands commonly used in DML include: update, insert, merge, select, delete, call, explain plan and lock table. | Commonly used commands in TCL include: submit, rollback, savepoint and set transaction. | | 9。 | by | Handling DML is handled by the query compiler and query optimizer of DBMS architecture. | TCL is handled by transaction manager and recovery manager. | | 10。 | locking | It uses locks for concurrency control. | Do not use locks. | | Eleven. | WHERE clause | Most DML statements have WHERE clauses to filter them. | TCL does not need a WHERE clause. | | Twelve. | Data access path | DML can be used to explain the access path of data. | TCL cannot explain the data access path. | | Thirteen. | call subroutine | Used to call PL/SQL or Java subprograms. | Not used to call subroutines. | | 14。 | Merge operation | We can use DML to merge. | TCL cannot perform the merge operation. | | Fifteen. | trigger | Trigger fires after DML statement. | TCL is not used for triggers. | | 16。 | example | Example of SQL query to find the names of all lecturers in the history department: Select the names From lecturers [T2】 WHERE dept _ name =' History '；; | 我们将使用 commit 命令永久保存表记录。如果我们想将乔利的名字更新为夏洛克并永久保存，我们可以使用以下内容， 更新学生 设置名称= '夏洛克' 其中名称= '乔利'；COMMIT； 回滚； |版权属于：月萌API www.moonapi.com，转载请注明出处
