Shulou(Shulou.com)05/31 Report--

In this issue, the editor will bring you about how to implement SELECT statements in a single table in the Oracle database. The article is rich in content and analyzes and describes for you from a professional point of view. I hope you can get something after reading this article.

The SELECT statement is used to retrieve information from a table in the database. In the simplest format, you only need to specify the table from which you want to retrieve the data and the name of the column to query. The SELECT statement in the following example retrieves the contents of the customer_id, first_name, last_name, dob, and phone columns from the customers table.

SELECT customer_id,first_name,last_name,dob,phone

FROM customers

In the above statement, the SELECT keyword is followed by the column name to be retrieved; the FROM keyword is followed by the table name that contains the column to be retrieved. The SQL statement ends with (;). After pressing the enter key at the end of the SQL statement, the statement is executed and the result is returned to SQL*plus and displayed on the screen. The following is the result returned:

All rows returned by the database are called result sets. As you can see, the Oracle database converts all column names to uppercase, and the characters and date columns are left-aligned. The data columns are aligned to the right. By default, the Oracle database displays the date in the form of DD-MON-YY, where DD is the number of days, MON is the first three letters of the month (uppercase), and YY is the two digits of the year. The database actually stores four digits for the year, but only the last two digits are displayed by default.

The above is the editor for you to share the Oracle database how to implement a single table to execute SELECT statements, if you happen to have similar doubts, you might as well refer to the above analysis to understand. If you want to know more about it, you are welcome to follow the industry information channel.

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