Create sql file in php

Create MySQL Database Using PHP

To create and delete a database you should have admin privilege. Its very easy to create a new MySQL database. PHP uses mysql_query function to create a MySQL database. This function takes two parameters and returns TRUE on success or FALSE on failure.

Syntax

bool mysql_query( sql, connection );

Required — SQL query to create a database

Optional — if not specified then last opend connection by mysql_connect will be used.

Example

Try out following example to create a database −

 echo 'Connected successfully'; $sql = 'CREATE Database test_db'; $retval = mysql_query( $sql, $conn ); if(! $retval ) < die('Could not create database: ' . mysql_error()); >echo "Database test_db created successfully\n"; mysql_close($conn); ?>

Selecting a Database

Once you establish a connection with a database server then it is required to select a particular database where your all the tables are associated.

This is required because there may be multiple databases residing on a single server and you can do work with a single database at a time.

PHP provides function mysql_select_db to select a database.It returns TRUE on success or FALSE on failure.

Syntax

bool mysql_select_db( db_name, connection );

Required — Database name to be selected

Optional — if not specified then last opend connection by mysql_connect will be used.

Example

Here is the example showing you how to select a database.

 echo 'Connected successfully'; mysql_select_db( 'test_db' ); mysql_close($conn); ?>

Creating Database Tables

To create tables in the new database you need to do the same thing as creating the database. First create the SQL query to create the tables then execute the query using mysql_query() function.

Example

Try out following example to create a table −

 echo 'Connected successfully'; $sql = 'CREATE TABLE employee( '. 'emp_id INT NOT NULL AUTO_INCREMENT, '. 'emp_name VARCHAR(20) NOT NULL, '. 'emp_address VARCHAR(20) NOT NULL, '. 'emp_salary INT NOT NULL, '. 'join_date timestamp(14) NOT NULL, '. 'primary key ( emp_id ))'; mysql_select_db('test_db'); $retval = mysql_query( $sql, $conn ); if(! $retval ) < die('Could not create table: ' . mysql_error()); >echo "Table employee created successfully\n"; mysql_close($conn); ?>

In case you need to create many tables then its better to create a text file first and put all the SQL commands in that text file and then load that file into $sql variable and excute those commands.

Consider the following content in sql_query.txt file

CREATE TABLE employee( emp_id INT NOT NULL AUTO_INCREMENT, emp_name VARCHAR(20) NOT NULL, emp_address VARCHAR(20) NOT NULL, emp_salary INT NOT NULL, join_date timestamp(14) NOT NULL, primary key ( emp_id ));

 $query_file = 'sql_query.txt'; $fp = fopen($query_file, 'r'); $sql = fread($fp, filesize($query_file)); fclose($fp); mysql_select_db('test_db'); $retval = mysql_query( $sql, $conn ); if(! $retval ) < die('Could not create table: ' . mysql_error()); >echo "Table employee created successfully\n"; mysql_close($conn); ?>

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Php – Create a .sql file in php

I have used the bellow code for get the wp-option value.

function option_value_change () < global $wpdb; $myrows = $wpdb->get_results( "SELECT * FROM `wp_options`"); foreach ($myrows as $rows)< $option = get_option($rows->option_name); $optin_id = $rows->option_id; $option_name = $rows->option_name; $option_value = $row->option_value; $option_load = $row->option_autoload; echo $option_value; > > 

now i want to create a .sql file using those above values. How can i create a .sql file using those values.

Best Solution

You have to generate the create table and insert statements manually. There is a good article here that has a backup script written in PHP.

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Php – How to prevent SQL injection in PHP

The correct way to avoid SQL injection attacks, no matter which database you use, is to separate the data from SQL, so that data stays data and will never be interpreted as commands by the SQL parser. It is possible to create SQL statement with correctly formatted data parts, but if you don’t fully understand the details, you should always use prepared statements and parameterized queries. These are SQL statements that are sent to and parsed by the database server separately from any parameters. This way it is impossible for an attacker to inject malicious SQL.

You basically have two options to achieve this:

Using PDO (for any supported database driver):

 $stmt = $pdo->prepare('SELECT * FROM employees WHERE name = :name'); $stmt->execute([ 'name' => $name ]); foreach ($stmt as $row) < // Do something with $row >

 $stmt = $dbConnection->prepare('SELECT * FROM employees WHERE name = ?'); $stmt->bind_param('s', $name); // 's' specifies the variable type => 'string' $stmt->execute(); $result = $stmt->get_result(); while ($row = $result->fetch_assoc()) < // Do something with $row >

If you’re connecting to a database other than MySQL, there is a driver-specific second option that you can refer to (for example, pg_prepare() and pg_execute() for PostgreSQL). PDO is the universal option.

Correctly setting up the connection

Note that when using PDO to access a MySQL database real prepared statements are not used by default. To fix this you have to disable the emulation of prepared statements. An example of creating a connection using PDO is:

$dbConnection = new PDO('mysql:dbname=dbtest;host=127.0.0.1;charset=utf8', 'user', 'password'); $dbConnection->setAttribute(PDO::ATTR_EMULATE_PREPARES, false); $dbConnection->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION); 

In the above example the error mode isn’t strictly necessary, but it is advised to add it. This way the script will not stop with a Fatal Error when something goes wrong. And it gives the developer the chance to catch any error(s) which are throw n as PDOException s.

What is mandatory, however, is the first setAttribute() line, which tells PDO to disable emulated prepared statements and use real prepared statements. This makes sure the statement and the values aren’t parsed by PHP before sending it to the MySQL server (giving a possible attacker no chance to inject malicious SQL).

Although you can set the charset in the options of the constructor, it’s important to note that ‘older’ versions of PHP (before 5.3.6) silently ignored the charset parameter in the DSN.

Explanation

The SQL statement you pass to prepare is parsed and compiled by the database server. By specifying parameters (either a ? or a named parameter like :name in the example above) you tell the database engine where you want to filter on. Then when you call execute , the prepared statement is combined with the parameter values you specify.

The important thing here is that the parameter values are combined with the compiled statement, not an SQL string. SQL injection works by tricking the script into including malicious strings when it creates SQL to send to the database. So by sending the actual SQL separately from the parameters, you limit the risk of ending up with something you didn’t intend.

Any parameters you send when using a prepared statement will just be treated as strings (although the database engine may do some optimization so parameters may end up as numbers too, of course). In the example above, if the $name variable contains ‘Sarah’; DELETE FROM employees the result would simply be a search for the string «‘Sarah’; DELETE FROM employees» , and you will not end up with an empty table.

Another benefit of using prepared statements is that if you execute the same statement many times in the same session it will only be parsed and compiled once, giving you some speed gains.

Oh, and since you asked about how to do it for an insert, here’s an example (using PDO):

$preparedStatement = $db->prepare('INSERT INTO table (column) VALUES (:column)'); $preparedStatement->execute([ 'column' => $unsafeValue ]); 

Can prepared statements be used for dynamic queries?

While you can still use prepared statements for the query parameters, the structure of the dynamic query itself cannot be parametrized and certain query features cannot be parametrized.

For these specific scenarios, the best thing to do is use a whitelist filter that restricts the possible values.

// Value whitelist // $dir can only be 'DESC', otherwise it will be 'ASC' if (empty($dir) || $dir !== 'DESC')

Sql – Add a column with a default value to an existing table in SQL Server

Syntax:

ALTER TABLE ADD   CONSTRAINT DEFAULT WITH VALUES 

Example:

ALTER TABLE SomeTable ADD SomeCol Bit NULL --Or NOT NULL. CONSTRAINT D_SomeTable_SomeCol --When Omitted a Default-Constraint Name is autogenerated. DEFAULT (0)--Optional Default-Constraint. WITH VALUES --Add if Column is Nullable and you want the Default Value for Existing Records. 

Notes:

Optional Constraint Name:
If you leave out CONSTRAINT D_SomeTable_SomeCol then SQL Server will autogenerate
a Default-Contraint with a funny Name like: DF__SomeTa__SomeC__4FB7FEF6

Optional With-Values Statement:
The WITH VALUES is only needed when your Column is Nullable
and you want the Default Value used for Existing Records.
If your Column is NOT NULL , then it will automatically use the Default Value
for all Existing Records, whether you specify WITH VALUES or not.

How Inserts work with a Default-Constraint:
If you insert a Record into SomeTable and do not Specify SomeCol ‘s value, then it will Default to 0 .
If you insert a Record and Specify SomeCol ‘s value as NULL (and your column allows nulls),
then the Default-Constraint will not be used and NULL will be inserted as the Value.

Notes were based on everyone’s great feedback below.
Special Thanks to:
@Yatrix, @WalterStabosz, @YahooSerious, and @StackMan for their Comments.

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