Linking a web page to a database
Linking a web page to a database
Learning objective :
link a web page to a database
The theme of the lesson :
Mutual evaluation of the practical task 1
Mutual evaluation of the practical task
1. In PhpMyAdmin, create a database named Institute.
2. Fill in the tables with the data for the teachers, courses, and lessons table
3. Link the tables together through the values of the id and tid records.
name of student | Table | The web page | |
lessons | |||
Courses | |||
Teachers | |||
To open a connection to the server
To open a connection to the server
Select database
Send query to database
Closing database (not always)
Connection to the database via php takes place in 4 stages:
Connecting to the server via php
Connecting to the server via php
Php function mysql_connect-opens a connection to a MySQL server.
Three parameters of the function:
"localhost" - server, when working locally, the value "localhost" is specified»
"root" — the user name, when working locally is usually specified " root»
""- the third parameter is password, no password locally
Create a variable associated with a connection to a mySql server:
Connecting to the server via php 2
Connecting to the server via php
2. Handling possible errors
or die (mysql_error()) The php mysql_error () function returns the error string of the last MySQL operation and can be used not only when trying to connect to the server, but also in other variants of working with the mysql database
Selecting a mySQL database and connecting to it
Selecting a mySQL database and connecting to it
Php function mysql_connect-selects MySQL database. Two function parameters:
"db_name" — database name
$conn — a pointer to the connection
Php mysql_query function-sends a request to the active database of the server referenced by the passed pointer
a pointer to the connection
echo $sql; |
Php mysql_query function-sends a request to the active database of the server referenced by the passed pointer. Two function parameters:
$sql — request
$conn — a pointer to the connection
Important: to find the error easier, you can print a query:
Processing of query results to mySQL database
Processing of query results to mySQL database
Php function mysql_fetch_array-returns an array with the processed query result series or FALSE if there are no rows that meet the query parameters
Example: print all entries for the surname
Example: print all entries for the surname Ivanov
The print_r() function in php is used to output human-readable information about a variable
Important: absolutely the same result will be an appeal to the field by its name and by its number:
echo $row["name"]; |
И echo $row[1]; |
Task: Run the query to fetch id and name from the teacher table
Task:
Run the query to fetch id and name from the teacher table.
Display the data on the web page as: id: name
Example: Select the value of the field "name" in the record number 1
mysql_result($result, 1, "name")
assessment verbal feature expression in points unsatisfactorily 1 almost satisfactory 2 satisfactorily 3 highly satisfactory 4 almost good 5 good 6 quite well 7 almost…
assessment
verbal feature | expression in points |
unsatisfactorily | 1 |
almost satisfactory | 2 |
satisfactorily | 3 |
highly satisfactory | 4 |
almost good | 5 |
good | 6 |
quite well | 7 |
almost perfect | 8 |
perfectly | 9 |
superbly | 10 |
ICT_10 класс_Linking a web page to a database. lesson 2
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