Notes MySQL Command select: the currently selected (connected) database

the Select command represents the currently selected (connected) database.

SELECT command format:mysql> Select Database ();

The Select command in MySQL is similar to print or write in other programming languages, and you can use it to display the results of a string, a number, a mathematical expression, and so on. How do I use the special features of the Select command in MySQL?

1) Show MySQL version
mysql> Select version ();
+-----------------------+ 
| version () |
+-----------------------+ 
| 6.0.4-alpha-community |
+-----------------------+ 
1 row in Set (0.02 sec)

2) Show current time
mysql> Select Now ();
+---------------------+ 
| Now () |
+---------------------+ 
| 2009-09-15 22:35:32 |
+---------------------+ 
1 row in Set (0.04 sec)

3) Display Month Day
SELECT DayOfMonth (current_date);
+--------------------------+ 
| DayOfMonth (current_date) |
+--------------------------+ 
| 15 |
+--------------------------+ 
1 row in Set (0.01 sec)
  
SELECT MONTH (current_date);
+---------------------+ 
| MONTH (current_date) |
+---------------------+ 
| 9 |
+---------------------+ 
1 row in Set (0.00 sec)
  
SELECT Year (current_date);
+--------------------+ 
| Year (current_date) |
+--------------------+ 
| 2009 |
+--------------------+ 
1 row in Set (0.00 sec)

4) Display string
mysql> Select "Welecome to my blog!";
+----------------------+ 
| Welecome to my blog! |
+----------------------+ 
| Welecome to my blog! |
+----------------------+ 
1 row in Set (0.00 sec)

5) When the calculator uses
Select ((4 * 4)/ten) +;
+----------------------+ 
| ((4 * 4)/10) + 25 |
+----------------------+ 
| 26.60 |
+----------------------+ 
1 row in Set (0.00 sec)

6) Threaded string
Select CONCAT (F_name, "", L_name)
As Name
From Employee_data
where title = ' Marketing Executive ';
+---------------+ 
| Name |
+---------------+ 
| Monica Sehgal |
| Hal Simlai |
| Joseph Irvine |
+---------------+ 
3 rows in Set (0.00 sec)

Note: the concat () function is used here to string strings together. In addition, we used the previously learned as to give the result column ' CONCAT (f_name, "", L_name) ' a pseudonym.

Notes MySQL Command select: the currently selected (connected) database