Selecting all columns with *
In SQL database language, you can preview by using * wildcard select all (asterisk) symbol to select all and individual table column value records from a particular database table. Where the table must already exist in the existing SQL software. In which the name of each table column is clearly given, all the table data and information from each column in the given table is displayed in the output console window.
Syntax of SELECT command in SQL.
SELECT * FROM table_name;
Remember, SELECT command in SQL database is the SQL reserved keyword used to get data from the table. Where the particular individual data and information can be displayed from the existing SQL database table as per the requirement.
Here * asterisk means “all columns.” Selecting in the existing database table.
Here in existing table in SQL, FROM option indicates the table from which SQL database table you want to display data and information.
Here in existing SQL command table_name is the name of the database table from which you want to display table records query with asterisks.
Example of SELECT command in SQL.
Here assume that you have a table named employe in SQL database with the following data.
Here to select all columns from the table named employe in existing SQL database. You can display all table records and database information of the below given employe table.
SELECT * FROM employe;
This displays all database table records from employe in SQL database.
When to use asterisks * select all command in SQL database.
Advantages of select all asterisks command in sql.
- Select command convenience – When you want to quickly explore a table in SQL database and you need to display all the data and information of a table. Then apply the Select All command in SQL.
- Select Ad-hoc query – When you are not sure about which specific columns of an existing table are required to be previewed in a particular SQL database table, and when you want to display all available column data from an existing table.
When to avoid * command in sql database.
- Select performance – If a database table has many columns, selecting all table columns with the * select command may be inefficient. Especially, when you are only interested in displaying some particular column values from the existing table.
- Select command clarity – You need to display the table columns of the existing database table. By explicitly selecting the column values, your table query becomes more readable and maintenance compatible.
Here is an example of displaying only name and age, salary columns in an existing employee table.
SELECT name,salary,age FROM employe;
Remember that using the * SELECT ALL command in a SQL database table allows you to quickly and easily select and display all columns and individual columns in a table. But for better database table preview and table column clarity, you can display only the columns you need.
