SQL statements for linux-SELECT and select

SQL statements for linux-SELECT and select

What is SQL used? The most common method is to select data from the database table. From this answer, we can immediately see two keywords:FROM (FROM)Tables in the databaseSELECT). (A table is a structure in a database. It aims to store data. InTable ProcessingIn this section, we will mention how to use SQL to set tables .) Here we can see the most basic SQL architecture:

SELECT "column name" FROM "table name ";

Let's use the following example to see how it is actually used. Suppose we have the following table:

Store_InformationTable

Store_Name	Sales	Txn_Date
Los Angeles	1500	05-Jan 1999
San Diego	250	07-Jan-1999
Los Angeles	300	08-Jan 1999
Boston	700	08-Jan 1999

If you want to select all store names (Store_Name), we will enter:

SELECT Store_Name FROM Store_Information;

Result:

Store_Name

Los Angeles

San Diego

Los Angeles

Boston

We can read several columns at a time, or select data from several tables at the same time.

Now let's take a look at the tested results in Linux:

Create a vpoetDB database first:

Create a Store_Information table in the vpoetDB database:

Insert a response record in the table:

SELECT statement:

Reprinted, please note: Xiao Liu