PHP implements reading and writing documents or images in the bytea field of postgresql

It took nearly two days to upload the space-based documents in batches. The original document was originally stored in the folder under the website directory as a file, and then stored in the bytea field of PostgreSQL. This field is equivalent to the blob or clob field of oracle, data is stored in a second-level system, with a maximum of 2 GB of data.

I am not familiar with PHP programming. I have read and write the bytea FIELD IN THE postgesql database only after reading a large amount of reference materials. I would like to share with you the following:

First, you need to modify the php. ini file under the PHP installation directory to enable extension = php_pdo_pgsql.dll and extension = php_pgsql.dll to connect to the PostgreSQL database.

// Create a database connection
Function Createpgconnect ()
{
$ Host = " Localhost " ;
$ Port = " 5432 " ;
$ Dbname = " GLC " ;
$ User = " Postgres " ;
$ Password = " Gxsnprg2010 " ;
$ Dbconn = Pg_connect ( " Host = $ Host Port = $ Port Dbname = $ Dbname User = $ User Password = $ Password " );
Return   $ Dbconn ;
}

 

 

Key to writing document data into bytea FieldCode

$ Dbconn=Createpgconnect ();//Database Connection // Insert the file into the database tb_doc_res_data
$ Tmpfile = Iconv ( " UTF-8 " , " GBK " , $ Tmpfile ); // $ Tmpfile is the file name, which is garbled Chinese characters.
$ Data = File_get_contents (Upload_file_path . $ Tmpfile ); // Complete Document path
$ Escaped = Pg_escape_bytea ( $ Data ); // Key Points
$ Insertsql = " Insert into tb_doc_res_data values ( " . $ Tb_docmaxid . " ,'{ $ Escaped }') " ;
$ Result3 = Pg_query ( $ Dbconn , $ Insertsql ); // Execute the insert statement command

 

Read the bytea field value and save it as a PDF file

Code

// /Read the file from the database
Function Readblob ()
{
$ Dbconn = Createpgconnect (); // Database Connection
$ Insertsql = " Select filecontent from tb_doc_res_data where docid = 5 " ; // Query statement
$ Query = Pg_query ( $ Dbconn , $ Insertsql );
$ Row = Pg_fetch_result ( $ Query , ' Filecontent ' );

$ Filecontent = Pg_unescape_bytea ( $ Row ); // Obtain binary data
File_put_contents (Upload_file_path . ' 11. PDF ' , $ Filecontent ); // Convert binary data into PDF files
Return   " OK " ;
}

 

References:

Http://php.net/manual/en/function.pg-unescape-bytea.php

Http://www.phpf1.com/manual/pg-escape-bytea.html

Http://www.phpf1.com/manual/pg-unescape-bytea.html

Http://bytes.com/topic/php/answers/157633-storing-images-postgresql-php

Http://www.zephid.dk/2008/08/09/oid-vs-bytea-in-postgresql/

Http://www.zhougang.name /? P = 395

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