Before we talk about the SQL language, we first define the contents of a small sales company relational database that contains the following relational tables:
▲office table. The columns of the table are: Office,city,region,mgr,target and sales, respectively, the department number, the city name of the sales office, the region name of the sales office, the Sales manager number, the sales department's target, and the sales department.
▲salesreps table. The columns of the table are: Empl--num,name,age,rep_office,title,hire_date,manager,quota and sales, respectively, the name of the sale office, the date of hire, the number of the salesperson's person, Sales staff quota and sales staff sales.
▲orders table. The columns of the table are: Order_num,order_date,cust,rep,mfr,product,qty and amout; The order number, the order date, the customer number, the sales department number, the manufacturer number, the product model number, the product quantity and the order amount.
1.SQL data Query statement
2.sql Data Add statement
3.sql Data Deletion statement
4.sql Data Modification Statement
5.SQL Database Structure Action statement
6.sql View Action Statement
7.sql Security Action Statement
8.sql Transaction Processing
References: SQL language tutorials SQL language basics
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