Timestamp is a data type in MySQL and works for different time zone. It is also used for date and time purpose To understand the concept, we need to create a table.Creating a tablemysql> CREATE table TimeStampDemo -> ( -> MyDataTime timestamp -> ); Query OK, 0 rows affected (0.57 sec)After creating the table, we will insert a record with the help of INSERT command.Inserting recordsmysql> INSERT into TimeStampDemo values (now()); Query OK, 1 row affected (0.12 sec)After inserting a record, we can display the records with the help of SELECT statement.Displaying recordsmysql> SELECT * from TimeStampDemo; After executing the ... Read More

The shortcoming of mysql_real_escape_string is as follows − It has main shortcoming in the modern API while we are making prepared statement. This has another shortcoming for every possible attack when you will typecast. Let us see the typecast syntax in MySQL − (TypeCast)mysql_real_escape_string($_REQUEST['anyColumnName'])); In the above syntax, we are typecasting, but in this case, it is not safer for every possible attack. The other cases include the following − It is not type safe. It is not for injection attack.

Yes, we can include a number for column name in MySQL. We need to use the symbol backtick, which is as follows( ` `)To understand, we will make a table with the help of CREATE command. Let us create a table −mysql> CREATE table NumberColumnDemo -> ( -> `123` varchar(100) -> ); Query OK, 0 rows affected (0.51 sec)Above, I have created a column name as a number with the help of backtick symbol.Now, we can check the same by inserting records with the help of INSERT command. Let us insert a record, which is as follows −mysql> INSERT into ... Read More

To understand whether a column exist or not, we have the following approaches −With the help of DESC commandUsing SHOW commandFirstly, we will create a table with columns −mysql> CREATE table ColumnExistDemo -> ( -> UniqueId int, -> UniqueName varchar(200), -> UniqueAddress varchar(200) -> ); Query OK, 0 rows affected (0.57 sec)In the first approach, we will get the entire column name with meaningful information. The syntax is as follows −DESC yourTableName; Let us apply the above query to check whether the column name exists or not. However, this approach is not good since it display all the columns.mysql> DESC ... Read More

The 1046 error occurs if you forget to select any database before creating a table. Let us see how and why this error occurs. We will try to create a table without selecting a database − mysql> CREATE table MyTable1 -> ( -> id int -> ); ERROR 1046 (3D000): No database selected Or mysql> INSERT into sample values(1); ERROR 1046 (3D000): No database selected Look at the output above, we are getting the same 1046 error: “No database selected” Now, we can resolve this error after selecting any ... Read More

To open root access from all hosts, we need to change the database to “mysql” with the help of USE command. The syntax of USE command is as follows − USE anyDatabasename; Now, I will use predefined database ‘mysql’, which is as follows − mysql> use mysql; Database changed I have changed the database above. Here is the query to get root access from the entire host − mysql> UPDATE user set host='%' where host='localhost'; Query OK, 6 rows affected (0.19 sec) Rows matched: 6 Changed: 6 Warnings: 0

Firstly, we need to create a table to understand the limit clause (as we want for SQL server).We will create a table with the help of CREATE command.Creating a tablemysql> CREATE table limitDemo -> ( -> id int, -> primary key(id) -> ); Query OK, 0 rows affected (0.58 sec)After that, let us insert records into the table −mysql> INSERT into limitDemo values(1); Query OK, 1 row affected (0.16 sec) mysql> INSERT into limitDemo values(2); Query OK, 1 row affected (0.12 sec) mysql> INSERT into limitDemo values(3); Query OK, 1 row affected (0.11 sec) mysql> INSERT into ... Read More

We can achieve this with the help of SHOW command. Firstly, I will use my database with the help of USE command −mysql> USE business; Database changedWe are in the “business” database now. After that, we can check that how many tables are available for this database. The query is as follows −mysql> SHOW tables; The following is the output+------------------------+ | Tables_in_business     | +------------------------+ | addcolumntable         | | autoincrement          | | autoincrementtable     | | bookindexes            | | chardemo           ... Read More

To add 5 hours in current time, we will use now() function from MySQL. The syntax is as follows −SELECT date_add(now(),interval some integer value hour);Now, I am applying the above query to add 5 hours to current time. The query is as follows −mysql> SELECT date_add(now(),interval 5 hour); The following is the output+---------------------------------+ | date_add(now(),interval 5 hour) | +---------------------------------+ | 2018-10-11 15:59:23 | +---------------------------------+ 1 row in set (0.00 sec)Look at the output above, it has increased the current time by 5 hours

Both are engine types. Here is the query by which we can get to know which engine type and tables are being used. Firstly, we will choose the database with the help of USE command − mysql> USE business; Database changed Here is the query through which we can know which table or engine is being used − mysql> SHOW table status; The following is the output +------------------------+--------+---------+------------+------+----------------+-------------+-----------------+--------------+-----------+----------------+---------------------+-------------+------------+--------------------+----------+----------------+---------+ |Name | Engine | Version | Row_format | ... Read More