What Are The Differences Between Mysql_fetch_array(), Mysql_fetch_object(), Mysql_fetch_row()?
Mysql_fetch_object is used to retrieve the result from the database as objects while mysql_fetch_array returns result as an array. This will allow access to the data by the field names.
For example:
Using mysql_fetch_object field can be accessed as $result->name.
Using mysql_fetch_array field can be accessed as $result->[name].
Using mysql_fetch_row($result) where $result is the result resource returned from a successful query executed using the mysql_query() function.
Example:
1.$result = mysql_query("SELECT * from students");
2.while($row = mysql_fetch_row($result))
3.{
4.Some statement;
5.}
How Do You Backup A Database In Mysql?
It is easy to backing up data with phpMyAdmin. Select the database you want to backup by clicking the database name in the left hand navigation bar. Then click the export button and make sure that all tables are highlighted that you want to backup. Then specify the option you want under export and save the output.
What Is Sqlyog?
SQLyog program is the most popular GUI tool for admin. It is the most popular MySQL manager and admin tool. It combines the features of MySQL administrator, phpMyadmin and others MySQL front ends and MySQL GUI tools.
What Is The Difference Between Char And Varchar?
A list of differences between CHAR and VARCHAR:
CHAR and VARCHAR types are different in storage and retrieval.
CHAR column length is fixed to the length that is declared while creating table. The length value ranges from 1 and 255.
When CHAR values are stored then they are right padded using spaces to specific length. Trailing spaces are removed when CHAR values are retrieved.
What Is The Difference Between Truncate And Delete In Mysql?
The DELETE command is used to delete data from a table. It only deletes the rows of data from the table while, truncate is very dangerous command and should be used carefully because it deletes every row permanently from a table.
How Many Triggers Are Possible In Mysql?
There are only six Triggers allowed to use in MySQL database.
Before Insert
After Insert
Before Update
After Update
Before Delete
After Delete
How to display top 50 rows?
In MySql, top 50 rows are displayed by using this following query:
SELECT * FROM
LIMIT 0,50;
1
2
SELECT * FROM
LIMIT 0,50;
How many columns can be used for creating Index?
Maximum of 16 indexed columns can be created for any standard table.
What is the different between NOW() and CURRENT_DATE()?
NOW () command is used to show current year,month,date with hours,minutes and seconds.
CURRENT_DATE() shows current year,month and date only.
What are the objects can be created using CREATE statement?
Following objects are created using CREATE statement:
DATABASE
EVENT
FUNCTION
INDEX
PROCEDURE
TABLE
TRIGGER
USER
VIEW
How many TRIGGERS are allowed in MySql table?
SIX triggers are allowed in MySql table. They are as follows:
BEFORE INSERT
AFTER INSERT
BEFORE UPDATE
AFTER UPDATE
BEFORE DELETE and
AFTER DELETE
What is the difference between mysql_fetch_array and mysql_fetch_object?
Following are the differences between mysql_fetch_array and mysql_fetch_object:
mysql_fetch_array() -Returns a result row as an associated array or a regular array from database.
mysql_fetch_object – Returns a result row as object from database.
How can we run batch mode in mysql?
Following commands are used to run in batch mode:
mysql ;
mysql mysql.out
1
2
mysql ;
mysql mysql.out
Where MyISAM table will be stored and also give their formats of storage?
Each MyISAM table is stored on disk in three formats:
The ‘.frm’ file stores the table definition
The data file has a ‘.MYD’ (MYData) extension
The index file has a ‘.MYI’ (MYIndex) extension
What are the different tables present in MySQL?
Total 5 types of tables are present:
MyISAM
Heap
Merge
INNO DB
ISAM
MyISAM is the default storage engine as of MySQL .
What is ISAM?
ISAM is abbreviated as Indexed Sequential Access Method.It was developed by IBM to store and retrieve data on secondary storage systems like tapes.
What is InnoDB?
lnnoDB is a transaction safe storage engine developed by Innobase Oy which is a Oracle Corporation now.
Mysql_fetch_object is used to retrieve the result from the database as objects while mysql_fetch_array returns result as an array. This will allow access to the data by the field names.
For example:
Using mysql_fetch_object field can be accessed as $result->name.
Using mysql_fetch_array field can be accessed as $result->[name].
Using mysql_fetch_row($result) where $result is the result resource returned from a successful query executed using the mysql_query() function.
Example:
1.$result = mysql_query("SELECT * from students");
2.while($row = mysql_fetch_row($result))
3.{
4.Some statement;
5.}
How Do You Backup A Database In Mysql?
It is easy to backing up data with phpMyAdmin. Select the database you want to backup by clicking the database name in the left hand navigation bar. Then click the export button and make sure that all tables are highlighted that you want to backup. Then specify the option you want under export and save the output.
What Is Sqlyog?
SQLyog program is the most popular GUI tool for admin. It is the most popular MySQL manager and admin tool. It combines the features of MySQL administrator, phpMyadmin and others MySQL front ends and MySQL GUI tools.
 |
| Daum MySQL Most Frequently Asked Latest Interview Questions Answers |
A list of differences between CHAR and VARCHAR:
CHAR and VARCHAR types are different in storage and retrieval.
CHAR column length is fixed to the length that is declared while creating table. The length value ranges from 1 and 255.
When CHAR values are stored then they are right padded using spaces to specific length. Trailing spaces are removed when CHAR values are retrieved.
What Is The Difference Between Truncate And Delete In Mysql?
The DELETE command is used to delete data from a table. It only deletes the rows of data from the table while, truncate is very dangerous command and should be used carefully because it deletes every row permanently from a table.
How Many Triggers Are Possible In Mysql?
There are only six Triggers allowed to use in MySQL database.
Before Insert
After Insert
Before Update
After Update
Before Delete
After Delete
How to display top 50 rows?
In MySql, top 50 rows are displayed by using this following query:
SELECT * FROM
LIMIT 0,50;
1
2
SELECT * FROM
LIMIT 0,50;
How many columns can be used for creating Index?
Maximum of 16 indexed columns can be created for any standard table.
What is the different between NOW() and CURRENT_DATE()?
NOW () command is used to show current year,month,date with hours,minutes and seconds.
CURRENT_DATE() shows current year,month and date only.
What are the objects can be created using CREATE statement?
Following objects are created using CREATE statement:
DATABASE
EVENT
FUNCTION
INDEX
PROCEDURE
TABLE
TRIGGER
USER
VIEW
How many TRIGGERS are allowed in MySql table?
SIX triggers are allowed in MySql table. They are as follows:
BEFORE INSERT
AFTER INSERT
BEFORE UPDATE
AFTER UPDATE
BEFORE DELETE and
AFTER DELETE
What is the difference between mysql_fetch_array and mysql_fetch_object?
Following are the differences between mysql_fetch_array and mysql_fetch_object:
mysql_fetch_array() -Returns a result row as an associated array or a regular array from database.
mysql_fetch_object – Returns a result row as object from database.
How can we run batch mode in mysql?
Following commands are used to run in batch mode:
mysql ;
mysql mysql.out
1
2
mysql ;
mysql mysql.out
Where MyISAM table will be stored and also give their formats of storage?
Each MyISAM table is stored on disk in three formats:
The ‘.frm’ file stores the table definition
The data file has a ‘.MYD’ (MYData) extension
The index file has a ‘.MYI’ (MYIndex) extension
What are the different tables present in MySQL?
Total 5 types of tables are present:
MyISAM
Heap
Merge
INNO DB
ISAM
MyISAM is the default storage engine as of MySQL .
What is ISAM?
ISAM is abbreviated as Indexed Sequential Access Method.It was developed by IBM to store and retrieve data on secondary storage systems like tapes.
What is InnoDB?
lnnoDB is a transaction safe storage engine developed by Innobase Oy which is a Oracle Corporation now.