看到很多人讨论SQL还分为四种类型,在这里知识普及一下,并总结下他们的区别吧。1. DDL – Data Definition Language数据库定义语言:定义数据库的结构。其主要命令有CREATE,ALTER,DROP等,下面用例子详解。该语言不需要commit,因此慎重。CREATE – to create objects in the database 在数据库创建对象例: CREATE DATA...
SQL Insert command is helpful to insert the data into a table. 1) All the column names are mentioned in the insert statement. Syntax INSERT INTO table_name (column1, column2, column3, ...) VALUES (value1, value2, value3, ...) Example INSERT INTO Student (StudendId, FirstName, Last...
DML (Data Manipulation Language) are SQL commands focused on handling data within the database, including most SQL statements. Let's look at some DML commands with a simple example for each command. i. INSERT INTO In SQL, theINSERT INTOstatement is used to insert new rows into a database ...
Statement stmt = conn.createStatement(); int rows = stmt.executeUpdate("INSERT INTO city VALUES (3,'china',1,'cc')"); // 设置事务保存点 svpt = conn.setSavepoint(); rows = stmt.executeUpdate("UPDATE city set country = 'TAIWAN' WHERE id = 4"); // 提交事务 conn.commit(); } catch...
Transaction Control Language (TCL) controls the time and effect of database transactions and monitors the database.GaussDB(DWS) uses the COMMIT or END statement to commit
Statement stmt = conn.createStatement(); int rows = stmt.executeUpdate("INSERT INTO city VALUES (3,'china',1,'cc')"); rows = stmt.executeUpdate("UPDATE city set country = 'TAIWAN' WHERE id = 4"); // 提交事务 conn.commit();
It is used in SQL (Structured Query Language), which is very interactive, portable, and works in multiple programs of PC, servers, and laptops. Users can easily access, edit, and save changes to the database. The coding required is not very complex. Even the new users can use it feasib...
Statement stmt = conn.createStatement(); int rows = stmt.executeUpdate("INSERT INTO city VALUES (3,'china',1,'cc')"); rows = stmt.executeUpdate("UPDATE city set country = 'TAIWAN' WHERE id = 4"); // 提交事务 conn.commit();
Common DML Commandsin SQL SELECT The SELECT statement retrieves data from one or more tables based on specified criteria: SELECT FirstName, LastName FROM Employees WHERE Department = 'Sales'; This query selects the first and last names of employees in the “Sales” department. ...
Statement stmt = conn.createStatement(); int rows = stmt.executeUpdate("INSERT INTO city VALUES (3,'china',1,'cc')"); // 设置事务保存点