SQL Expressions
7 rows in set (0.00 sec)
Here is simple example showing usage of SQL Boolean Expressions:
SQL> SELECT * FROM CUSTOMERS WHERE SALARY = 10000;
+----+-------+-----+---------+----------+
| ID | NAME | AGE | ADDRESS | SALARY |
+----+-------+-----+---------+----------+
| 7 | Kumar | 24 | Indore | 10000.00 |
+----+-------+-----+---------+----------+
1 row in set (0.00 sec)
SQL - Numeric Expression:
This expression is used to perform any mathematical operation in any query. Following is the syntax:
SELECT numerical_expression as OPERATION_NAME
[FROM table_name
WHERE CONDITION] ;
Here numerical_expression is used for mathematical expression or any formula. Following is a simple examples showing usage of SQL Numeric Expressions:
SQL> SELECT (15 + 6) AS ADDITION
+----------+
| ADDITION |
+----------+
| 21 |
+----------+
1 row in set (0.00 sec)
There are several built-in functions like avg(), sum(), count(), etc., to perform what is known as aggregate data calculations against a table or a specific table column.
SQL> SELECT COUNT(*) AS "RECORDS" FROM CUSTOMERS;
+---------+
| RECORDS |
+---------+
| 7 |
+---------+
1 row in set (0.00 sec)
SQL - Date Expressions:
Date Expressions return current system date and time values:
SQL> SELECT CURRENT_TIMESTAMP;
+---------------------+
| Current_Timestamp |
+---------------------+
| 2009-11-12 06:40:23 |
+---------------------+
1 row in set (0.00 sec)
Another date expression is as follows:
SQL> SELECT GETDATE();;
+-------------------------+
| GETDATE |
+-------------------------+
| 2009-10-22 12:07:18.140 |
+-------------------------+
1 row in set (0.00 sec)
SQL CREATE Database
The SQL CREATE DATABASE statement is used to create new SQL database.
Syntax:
Basic syntax of CREATE DATABASE statement is as follows:
CREATE DATABASE DatabaseName;
Always database name should be unique within the RDBMS.
Example:
If you want to create new database , then CREATE DATABASE statement would be as follows:
SQL> CREATE DATABASE testDB;
Make sure you have admin privilege before creating any database. Once a database is created, you can check it in the list of databases as follows:
SQL> SHOW DATABASES;
+--------------------+
| Database |
+--------------------+
| information_schema |
| AMROOD |
| TUTORIALSPOINT |
| mysql |
| orig |
| test |
| testDB |
+--------------------+
7 rows in set (0.00 sec)
